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HomeMy WebLinkAbout1.07 Appendix G - Floodplain Application March 29, 2021 Attn: Glenn Hartmann Senior Planner Garfield County Planning Division ghartmann@garfield-county.com (970) 945-1377 x1570 Narrative for the Amended Rifle Pit Floodplain Application FDPA-08-20-8801 This narrative is written on behalf of IHC-Scott to address an amended mining plan for the Rifle Pit Property (Parcel No 217-908-300-103) based on the public comment period and County review for the associated Land Use Change application process for MIPA-05-20-8788. This amended application is also written to address all technical items that have been addressed during County staff review of FDPA-08-20-8801 to-date. An estimated 100-year floodplain and floodway delineation were determined by SGM in order to address the pertinent sections of the County Land Use Development Code (LUDC). Neither the floodplain nor the floodway is currently mapped based on FEMA panel 0802051360B dated 12/15/1977. SGM predicts that the proposed development at the Rifle Pit will result in no-rise to the base-flood elevation (BFE). Amended Mining Plan and Project Description Rifle Pit #1 is a proposed sand and gravel mine within a 58.7-acre property located in unincorporated Rifle, Colorado, at Garfield County parcel 217-908-300-103. The proposed Rifle Pit #1 is just north of Interstate 70 (I-70), roughly 1-mile northeast of the Rifle Airport. The 100-year floodplain delineation (shown in Attachment 1) does include a small portion of the proposed Rifle Pit #1, though much of the property is outside the 100-year floodplain delineation. Areas within the 100-year floodplain delineation are predicted to experience flood depths of approximately 3-ft, in what may be classified as a shallow flooding zone. IHC Scott has amended the proposed mining plan based on feedback from the County during its review of the technically complete application and the County’s consultations with other jurisdictional bodies, including but not limited to the US Army Corps of Engineers (USACE). IHC Scott’s proposed amended mining plan will avoid all existing wetland areas and any irrigation/drainage structures on the Rifle Pit property. SGM has developed an updated civil engineering sheet set (Attachment 1) since the initial submission of application for FDPA-08-20-8801 that reflect the amended mining plan. The amended proposed mining plan includes two stages (down from six in the original mining plan) for a total disturbance of 27.70 acres (down from roughly 50 acres in the original mining plan), approximately 7.68 acres are within the 100-year floodplain (down from roughly 9.1 acres in the original mining plan). www.s gm-inc.co m GLENWOOD SPRINGS 118 West Sixth St, Suite 200 | Glenwood Springs, CO 81601 | 970.945.1004 The amended Rifle Pit #1 project is expected progress in the following proposed phases from May 2021 to December 2027: 1) Phase 1 – Site Development and Dewatering a. Topsoil will be stripped from the proposed Mining Stage 1 Limits of Disturbed Area (LDA) shown in Attachment 1. Topsoil will be used to construct a perimeter berm along the LDA, and a silt fence will be installed around the existing wetland areas and the tailwater channel to prevent any disturbance. Excess topsoil will be stockpiled within the mining areas or on the operations pad. The stockpiles may need to be relocated during mining activities. A 1.6-acre operations pad will also be constructed to house parking, scale house, sanitary facilities, etc. b. Dewatering is proposed to be accomplished through the use of strategically placed wells on the property as well as a dewatering trench at the mine floor, as needed. IHC Scott will obtain the necessary dewatering permits prior to commencement of dewatering operations. See Attachment 9 for more details on dewatering analysis. c. A dewatering pipeline will be constructed on the neighboring Shidelerosa LLLP property, as shown on plans in Attachment 1. This pipeline will convey pumped, clean dewatering water to the discharge point shown in civil engineering plans and details. 2) Phase 2 – Mining Stages a. Stage 1 i. This 18.04-acre area will be mined according to the typical mining section shown on Sheet C5 of Attachment 1. ii. The existing drivable access over the tailwater channel will be refurbished in its present location with a new culvert and overburden to maintain existing hydraulic conveyance capacity of the tailwater channel and to allow for safe access to the area shown in Attachment 1 as Stage 2. b. Stage 2 i. This 8.70-acre area will be mined according to the typical mining section shown on Sheet C6 of Attachment 1. 3) Phase 3 – Reclamation a. Reclamation of the site will entail recontouring of the mined area to provide a wetland buffer, as shown on the detail on Sheet C8 of Attachment 1. b. The site will be revegetated based on the planting schedules shown in the Notes and Tables 1 & 2on Sheet C9 of Attachment 1. Floodplain Model Considerations The modeled floodplain and floodway delineations, which are detailed in the Updated Floodplain Engineering Report (Attachment 2), are based upon IHC Scott’s original mining plan that assumed nearly the entire property area would be mineable. As such, the flood model developed by SGM represents a hypothetical “fully developed” condition of the Rifle Pit property; from the perspective of flood impacts, this would be considered the worst-case scenario for impacts to the floodplain and BFE. Given that the model detailed in Attachment 2 assumes a much larger impact to the floodplain, the proposed amended mining plan impacts will be no greater than those predicted by the model. www.sgm-inc.com The findings of the Updated Floodplain Engineering Report in Attachment 2 show that there will be no-rise to the BFE as a result of development of the Rifle Pit property. A notable amendment to the proposed development of the Rifle Pit property is a proposed dewatering pipeline alignment through the neighboring Shidelerosa LLLP property (Garfield County Parcel ID 217-908-100-527). The dewatering pipeline will be buried at a depth of 1.5 to 2-feet below existing grade and discharge clean groundwater to the Colorado River. Though the buried dewatering pipeline alignment is shown inside the modeled floodplain and floodway delineations, there will be no changes to existing grades and consequently no impact on the base-flood elevation (BFE). IHC Scott Inc has secured a lease and use agreement for the Shidelerosa LLLP property, which can be provided at the County’s request. Updated Title Commitment An updated title commitment for the Rifle Pit property (Parcel No 217-908-300-103), dated September 8, 2020 is included in Attachment 3. Address List and Owners of Parcel No. 2179-083-00-102 An updated mailing list for nearby parcels, including a complete list of owners for Parcel No 2179-083-00-102 is included as Attachment 4. Analysis of Land Use Regulations 3-301 (A) Use Restrictions in the Floodplain Overlay Per Table 3-301, the proposed gravel extraction is permitted in the 100-year floodplain but outside of the floodway. Sheet C1 of Attachment 1 shows that the 100-year floodplain covers a portion of the Rifle Pit property and that the floodway does not cover any portion of the Rifle Pit property. 3-301 (B) General Standards A proposed mobile or prefabricated office/scale-house building is to be placed outside of the floodplain, somewhere inside the designated “Operational Pad” area shown on Attachment 1. As a precaution against the unlikely case of shallow inundation, SGM recommends that any structures be anchored to reinforced concrete caissons and built with a lowest finished floor elevation of 5385.14’, or 1-foot above the modeled 100-year floodplain water surface elevation in the vicinity of the operations pad area. No permanent structures or hazardous material storage areas are to be placed within the actively mined gravel pit area. No new or replacement water supply or sanitary sewer systems are proposed to be installed at the Pit. Drinking water will be delivered to the site and sewerage will be collected in portable toilets and pumped regularly by a contracted service. An on-site waste disposal system is not deemed feasible with the proposed dewatering activities during mining. It is expected that the dewatering activities would influence the functionality of the on- site waste disposal system. www.sgm-inc.com 3-301 (C) Specific Standards There are no defined BFE’s in this area; Zone A is an unstudied approximate floodplain. There are no proposed structures to be constructed or placed inside the modeled floodplain. As a precaution against the unlikely case of shallow inundation, SGM recommends that any structures be anchored to reinforced concrete caissons and built with a lowest finished floor elevation of 5385.14’, or 1-foot above the modeled 100-year floodplain water surface elevation in the vicinity of the operations pad area. 3-301 (D) Floodway This section of the LUDC does not apply as the Pit is not located within the estimated extents of the floodway. Sheet C1 of Attachment 1 shows the floodway delineation is approximately 926-feet away from the northern property boundary at its closest approach. 3-301 (E) Standards for Areas of Shallow Flooding The property is not currently in a designed Special Flood Hazard Area (SFHA) as it has not been mapped by FEMA. But as a precaution against the unlikely case of shallow inundation, SGM recommends that any structures be anchored to reinforced concrete caissons and built with a lowest finished floor elevation of 5385.14’, or 1-foot above the modeled 100-year floodplain water surface elevation in the vicinity of the operations pad area. 3-301 (F) Properties Removed from the Floodplain by Fill This section does not apply as no areas will be removed from the floodplain by fill. The proposed berm and other modifications of the site have been modeled to show a no-rise of the BFE, which is detailed in Attachment 2. 3-301 (G) Alteration of a Watercourse This section does not apply, no watercourse shall be changed with the proposed uses at the Rifle Pit. 3-301 (H) Standards for Critical Facilities This section does not apply because the proposed development of the Rifle Pit property does not meet the definition of a critical facility. Section 4-102 SGM has engaged the County staff throughout the permitting process and held a specific pre-application conference meeting to address the Floodplain Development Permit application. The remaining review procedures are pending submittal of this application. Mailed notice will be sent to neighbors following acceptance of this floodplain application by the County. A list of neighboring properties that will receive mail notice of this application are shown in Attachment 4. www.sgm-inc.com Section 4-109 (C) 1. The perimeter berm is designed to mitigate the risk of danger to life and minimize the risk of property damage inside the Rifle Pit. The berm shall be constructed at least 5-feet high with 2:1 revegetated side- slopes along the property’s boundary. The top-of-berm elevation is therefore no less than 4-feet above the BFE. The berm is designed to sustain the hydrodynamic forces and shear stresses exerted by the 100-year flood event and prevent inundation inside the Rifle Pit. In addition, there is no predicted significant increase in floodplain elevations as a result of the proposed development, therefore, no adverse impacts to adjacent properties will result from the proposed development (see Attachment 2). 2. The site is susceptible to inundation, but that risk is mitigated with the proposed berm (discussed above). Hydrodynamic parameters in the vicinity of the Rifle Pit during the 100-year storm event have been modeled and are summarized in Table 2 of Attachment 2. Velocities and shear stresses are expected to be less than 3 feet per second (fps) and 1 pound per square foot (psf), respectively. Under those conditions, the hydrodynamic and hydrostatic forces are considered insufficient to breach the proposed berm. 3. Predicted velocities during the 100-year flood are not sufficient to carry materials onto to other properties. The perimeter berm is designed to withstand the hydrodynamic and hydrostatic forces of the 100-year flood and will further prevent material from being carried off-site onto other properties. 4. The proposed use of the Pit as a gravel mining and extraction site is pending approval of a Land Use Change application MIPA-05-20-8788 and the adequacy of proposed uses are addressed in that application and follow-up responses to a Not Technically Complete application. Adjacent properties have similar uses that seem to be compatible with this development. Future development of adjacent properties with more restrictive uses is unlikely due to floodplain inundation in the vicinity. 5. Access to the property from County Road 346 (CR-346) is to be developed according to CDOT Access Permit #320024, included as Attachment 5. The proposed access point from CR 346 is outside of the modeled floodplain. 6. Neither the existing or proposed condition of the property will have public utilities, paved streets, bridges, or any other government services that will require repair after a flood event. On-site drinking water will be delivered, and sewerage will be collected in portable toilets and pumped regularly by a contracted service. 7. The average water velocity at the site during the 100-year flood is expected to be 2.7-fps with a depth of 3.2-feet and shear stress of 0.6-psf. 8. Does not apply – property is not a waterfront location. 9. There is no alternative location for mining and gravel extraction on the property. The operations pad and scale-house/office are shown to be located outside of the floodplain. 10. The Pit property is located within a Residential Medium High (Res MH) area and adjacent to the Urban Growth Area for Silt, CO, according to the Garfield County 2030 Comprehensive Plan. The Res MH areas in www.sgm-inc.com the county are expected to be developed at a density of between 1 dwelling unit (du) per 6 acres and 1 du per 2 acres; however, due to the area around the project site being within the designated 100 -year floodplain (as shown on the future land use map) it is unlikely to be developed with residential uses. The proposed development of the property does not include any housing or dwelling units as the property will be used for gravel mining and extraction. Pending approval of the Land Use Change application MIPA-05- 20-8788, the proposed development and use of the property will be coherent with the County’s zoning designation. Section 4-201 SGM has developed all required materials for submittal of the Floodplain Development Permit FDPA-08-20-8801. Section 4-203 (O) The extent of the 100-year floodplain and floodway have been more clearly labeled in Attachment 1. The area designated for a potential office/scale-house site, labeled “Operational Pad Area” is outside of the modeled 100- year floodplain. As a precaution against the unlikely case of shallow inundation, SGM recommends that any structures be anchored to reinforced concrete caissons and built with a lowest finished floor elevation 5385.14’, or 1-foot above the modeled 100-year floodplain water surface elevation in the vicinity of the operations pad area. IHC Scott will be required to apply for coverage under Permit COG603000, Discharges from Subterranean Dewatering Activities. It should be noted that this permit only covers situations where the source water is NOT expected to be contaminated and means that IHC Scott has no reason to believe the Rifle Pit #1 property is in an industrial area or near known sources of groundwater contamination. The Water Quality Control Division can request analytical data be collected and submitted prior to issuing a Permit Certification for coverage and can also require the applicant to collect samples over a two-year period to prove that the source water doesn’t exceed the water quality standards of the receiving water. The permit limits are different for discharges to surface water versus discharges to groundwater. This permit will also require the use of a settling basin to remove sediment. A preconstruction elevation certificate will be provided prior to the start of any construction. Sections 7-203 (A)-(D) All existing waterbodies, as defined in the Garfield County Land Use Regulations, including wetlands, will be avoided in the amended mining plan. Existing wetland areas and the tailwater channel will be protected with fencing along the 35-foot buffer from the waterbody edge. IHC Scott has installed 9 piezometers for the purpose of monitoring water surface elevations of shallow groundwater in and around the existing wetlands. The data collected during this piezometer study will be analyzed and inform the hydrologic conditions for the wetlands, i.e. whether or not they area agriculturally induced (i.e. outside of the jurisdiction of USACE) or if the groundwater is derived from more permanent natural aquifer sources (within the jurisdiction of USACE). See Attachment 6 for more details about the wetlands findings and a site plan of the Rifle Pit piezometer layout. www.sgm-inc.com Conclusion This Floodplain Development Permit narrative was written as a stand-alone document that is intended to address all land use code sections pertinent to this Floodplain Development application. For reference materials, Attachments 7-9 are also included here, even though they were provided in previous application materials during review of FDPA-08-20-8801. If you have any questions, please contact me at 303-746-2549 or chipf@sgm-inc.com. Sincerely, Richard (Chip) Fisher, PE Attachments: (1) Updated Civil Engineering Sheet Set (showing Amended Mining Plan) (2) Updated Floodplain Development Engineering Report (3) Updated Rifle Pit #1 Property Title Commitment (4) Updated Mailing List for Nearby Parcels (5) CDOT Access Permit #320024 (6) Piezometer Study Environmental (Wetlands) Findings Summary and Supplement (7) Statement of Authority (8) Pre-application Summary and NTC Letter (9) Dewatering Analysis and Reports www.sgm-inc.com Attachment 1 www.sgm-inc.com Project EngineersVicinity MapSheet IndexOwner/ApplicantScope of Work Drawings and engineering design for DRMS 112 Permit, Garfield County Land Use Change,and Garfield County Floodplain Development Permit Applications.118 West Sixth Street, Suite 200Glenwood Springs, CO 81601970.945.1004 www.sgm-inc.com Project SiteScott Contracting, Inc.Rifle Pit No. 11-COVER - Cover SheetC1 - Disturbance Summary PlanC2 - Floodplain Specific Site PlanC3 - Dewatering Pipeline PlanC4 - Dewatering Pipeline GeometryC5 - Mining Plan (Stage 1 of 2)C6 - Mining Plan (Stage 2 of 2)C7 - Erosion Control PlanC8 - Reclamation PlanC9 - Notes & Details (1)C10 - Notes & Details (2)C11 - Notes & Details (3)Scott Contracting IncMarch 20219200 East Mineral Ave, Suite #400Centennial, CO 80112Title:Cover SheetRevision#Dwg No.Scott Contracting, Inc. Rifle Pit No. 1Job No.Drawn by:Date:File:QC:2019-341.002RPF03.29.2021RPFRiflePit-Admin-17X11118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By:1-COVER 12Of :PE:ABFPermit Set (Not For Construction)Project Milestone:Jevon Poston, P.E. 57316Richard (Chip) Fisher, P.E. 57906N.T.S.Permit Set (Not For Construction) © 2020 Microsoft Corporation © 2020 Maxar ©CNES (2020) Distribution Airbus DS Title:DisturbanceSummary PlanRevision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-SitePlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C1 12Of :Graphic ScaleIn Feet: 1" = 500'02505001000Scott Contracting, Inc. Rifle Pit No. 1 © 2020 Microsoft Corporation © 2020 Maxar ©CNES (2020) Distribution Airbus DS Title:Floodplain SpecificSite PlanRevision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-FloodplainPlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C2 12Of :Graphic ScaleIn Feet: 1" = 1000'050010002000Scott Contracting, Inc. Rifle Pit No. 1 © 2020 Microsoft Corporation © 2020 Maxar ©CNES (2020) Distribution Airbus DS Title:DewateringPipeline PlanRevision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-SitePlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C3 12Of :Graphic ScaleIn Feet: 1" = 500'02505001000Scott Contracting, Inc. Rifle Pit No. 1 Title:DewateringPipelineGeometryRevision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-SitePlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C4 12Of :Graphic ScaleIn Feet: 1" = 500'0250Scott Contracting, Inc. Rifle Pit No. 1 5001000 Title:Mining Plan(Stage 1 of 2)Revision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-GrDrPlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C5 12Of :Graphic ScaleIn Feet: 1" = 200'0100Scott Contracting, Inc. Rifle Pit No. 1 200400 Title:Mining Plan(Stage 2 of 2)Revision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-GrDrPlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C6 12Of :Graphic ScaleIn Feet: 1" = 200'0100Scott Contracting, Inc. Rifle Pit No. 1 200400 Title:Erosion ControlPlanRevision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-GrDrPlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C7 12Of :Graphic ScaleIn Feet: 1" = 200'0100Scott Contracting, Inc. Rifle Pit No. 1 200400 Title:Reclamation PlanRevision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-GrDrPlanABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C8 12Of :Graphic ScaleIn Feet: 1" = 200'0100Scott Contracting, Inc. Rifle Pit No. 1 200400 Title:Notes & Details (1)Revision#Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-DetailsABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C9 12Of :Scott Contracting, Inc. Rifle Pit No. 1 Dwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-DetailsABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C10 12Of :Title:Notes & Details (2)Revision# Scott Contracting, Inc. Rifle Pit No. 1 ····FIXED COVER4" [10.16 CM] W X 1/2" [1.27 CM] TBASE MOUNTING FLANGEFIXED ENERGYABSORBING PLATE60" [152.4 CM] I.D.MANHOLE BARREL(MIN 1/2" [1.27 CM] T)Ø12"FLOWØ2'[30.48 CM]SCH 80[60.96CM ]SDR 266'-4" [193.04CM ]PLAN VIEW(DOMED TOP NOT SHOWN FOR CLARITY)FIBERGLASS DOMED TOPWITH CONFINED SPACEENTRY SIGN AND STAINLESSSTEEL GAS STRUT, HINGE,AND HASP1' [30.48CM ]TYPICALGRADE6'[182.88CM ]MANHOLE DEPTH5"[12.70CM ]5 17/64"[13.39CM ]FOAM PADCONCRETE PAD (BY OTHERS)6" [15.24 CM] T MINIMUMELEVATION CROSS-SECTION VIEWFLOWDwg No.Job No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.29.2021RPFRiflePit-DetailsABF118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Permit Set (Not For Construction)Project Milestone:C11 12Of :Title:Notes & Details (3)Revision# Scott Contracting, Inc. Rifle Pit No. 1 Attachment 2 www.sgm-inc.com December 7, 2020 Glenn Hartmann Senior Planner Garfield County Planning Division ghartmann@garfield-county.com (970) 945-1377 x1570 Updated Floodplain Development Engineering Report Introduction This memo was prepared by SGM on behalf of Scott Contracting Inc. (SCI) and summarizes the results of HEC-RAS modeling used to predict the impacts of a proposed gravel pit (Rifle Pit #1) to the 100-year flood event/floodplain. The Rifle Pit #1 is in Rifle, CO, in between the City of Rifle and the Town of Silt (Garfield County Parcel ID 217908300103). Development of the site will entail mining of sand and gravel. Placement of any structures on-site will be temporary, moveable, and limited to those necessary to support operations to mine, process, and transport sand and gravel. The site will be flood-proofed using an earthen berm of approximately 5 above ground surface, to hold back any flood waters during the 100-yr (1%) event, as well as mitigate industrial noise. A buried dewatering pipeline will be installed through the neighboring Shidelerosa LLLP property (Garfield County Parcel ID 217908100527) approximately 1.5-2 feet below existing grade in the floodplain and floodway but will not impact the BFE because installation of the pipeline will not change existing grades. There are no residential construction activities planned for the site. See associated Civil Engineering sheet set for site development plans. The region near the proposed Rifle Pit #1 has not been mapped by FEMA so neither the floodplain nor floodway has been determined, based on panel 0802051360B dated 12/15/1977. HEC-RAS Model Inputs Flow and Boundary Conditions The CWCB analyzed hydrology of the Colorado River and determined that the 100-year (1%) flow is projected to be 34,900 (cubic feet per second) which was used as the steady-state flow in both existing and proposed conditions of the model. The boundary condition for both existing and proposed conditions was set to a Normal Depth at the downstream cross-section (River Station 175063.0) with a slope () of 0.225%, as determined from LiDAR elevations. Existing Conditions Geometry Existing conditions were derived from Garfield County LiDAR topography. The HEC-RAS existing condition geometry (i.e., cross-sections, riverbank locations, ineffective flow areas, and river flowline) is shown in Error! Reference source not found. An existing gravel pit, just west of the Proposed Rifle Pit #1, was modeled as an obstruction after analyzing aerial imagery that shows the pit does not fill with water. www.s gm-inc.co m GLENWOOD SPRINGS 118 West Sixth St, Suite 200 | Glenwood Springs, CO 81601 | 970.945.1004 Proposed Conditions Geometry Proposed conditions were developed in AutoCAD to reflect the mining operation phase of the project (see associated Civil Engineering sheet set) and inserted in the LiDAR surface to create a hybrid surface. The HEC-RAS proposed condition geometry is shown in Figure 2. The Proposed Rifle Pit #1 was modeled as an obstruction within the perimeter berm to prevent flow from entering the pit and erroneously decreasing the WSE in the model. www.sgm-inc.com Figure 1. Map showing LiDAR topography of the Existing Condition and the model cross sections (light green lines), river flowline (blue line) and the left and right banks of the river (red dots). www.sgm-inc.com Figure 2. Map showing hybrid AutoCAD/LiDAR topography of the Proposed Condition and the model cross sections (light green lines), river flowline (blue line) and the left and right banks of the river (red dots). www.sgm-inc.com HEC-RAS Floodplain Model Results A hydraulic model was developed using HEC-RAS to simulate flooding effects during the 100-year flood event both before and after the proposed mining operation. Hydraulic stresses were analyzed to determine appropriate erosion control and structural characteristics of the earthen berm to withstand flood conditions. The difference between the existing and proposed WSE was computed as the rise in the WSE. A summary of the model WSE results provided in Table 1. Table 1. Summary of HEC-RAS model results: existing and proposed water surface elevation (WSE) and the computed rise (i.e. difference between existing and proposed WSE) at each river station. River Station Existing WSE Proposed WSE Rise ft ft ft 30902.14 5412.3 5412.3 0.0 29650.64 5409.4 5409.4 0.0 29500 Bridge Bridge N/A 29427.62 5406.2 5406.2 0.0 27494.84 5400.4 5400.4 0.0 26255.61 5397.1 5397.1 0.0 25219.46 5393.1 5393.1 0.0 24101.01 5389.9 5389.9 0.0 22688.22 5385.4 5385.4 0.0 20730.67 5379.1 5379.1 0.0 19398.23 5375.5 5375.5 0.0 17708.26 5371.8 5371.8 0.0 15834.35 5365.6 5365.6 0.0 13915.69 5359.6 5359.6 0.0 In the proposed condition geometry (Figure 2), cross-sections 22688.22 and 20730.67 include the proposed Rifle Pit #1 (earthen berm and mining pit). Hydraulic stress, depth, and velocity at these cross sections as well as the nearest upstream and downstream cross sections were used as design parameters for the construction of the earthen berm. Table 2 below summarizes the model results at these cross-sections. Based on these results, the earthen berm shall be built at 2H:1V slope, seeded with native grass blends, and stabilized with erosion control blankets until the native vegetation has established. Details for the seed blend and erosion control blanket installation are shown in on Sheet C3 of the Civil Engineering Sheet Set. Appendix A includes cross-sections and associated modeling results. www.sgm-inc.com Table 2. Summary of HEC-RAS model results: velocity, hydraulic depth, and shear stress of the left over-bank region of the four nearest cross- sections to the proposed Rifle Pit #1. River Station Velocity Hydraulic Depth Shear Stress ft ft/s ft lb/sq.ft. 24101.01 2.0 2.8 0.4 22688.22† 2.8 2.6 0.7 20730.67† 2.7 3.2 0.6 19398.23 2.4 3.5 0.5 † Cross-sections cutting through the proposed Rifle Pit #1. HEC-RAS Floodway Encroachment Results The sections above described the development and results of a HEC-RAS hydraulic model that was used to prepare a no-rise certification based on the proposed development of the Rifle Pit #1. SGM used the same HEC-RAS model to implement an encroachment analysis, where the effective flow area in the model has been incrementally decreased until the predicted water surface elevations at each modeled cross-section increased by 0.5 feet, as described in Rule 8 of 2 CCR 408-1. An encroachment analysis was used to estimate the floodway, using an iterative process of decreasing the effective flow area at each modeled cross-section by starting downstream at River Station 13915.69 and moving upstream. Some cross-sections showed no change in water surface elevation (WSE) so the floodway delineation is approximated as the stream bank at those cross-sections, which is defined in the model geometry. Left and Right Offsets for the floodway delineations are summarized below in and overlaid with the model geometry and topography in Figure 3. www.sgm-inc.com Figure 3. Encroachment Analysis results map showing the floodway (pink line) and the floodplain (black) delineations. www.sgm-inc.com www.sgm-inc.com Table 3. Summary of left and right offsets for the floodway encroachment at each model cross-section. Cross-section (River Station) Left Floodway Stationing Left Bank Stationing Right Bank Stationing Right Floodway Stationing Predicted Surcharge ft ft ft ft Ft 30902.14 1597.59 1956.95 2317.12 2421.92 0.50 29650.64 326.82 336.82 798.40 808.41 0.00 29500 Bridge Bridge Bridge Bridge 0.00 29427.62 356.90 366.90 982.50 992.50 0.50 27494.84 731.93 1401.12 2094.84 2104.84 0.50 26255.61 950.92 1974.18 2547.44 2557.44 0.50 25219.46 1391.78 1974.18 2547.44 3153.62 0.28 24101.01 1590.08 2483.80 2953.56 3982.04 0.50 22688.22 2402.02 3158.24 3981.04 5018.53 0.50 20730.67 3270.79 4559.40 5003.53 5510.56 0.50 19398.23 3012.35 4964.81 5448.56 5944.03 0.50 17708.26 3589.25 5386.70 5984.03 5751.30 0.50 15834.35 3052.93 3062.93 4872.42 4882.42 -0.10 13915.69 1935.13 1945.13 3731.21 3741.21 0.50 Conclusions The proposed Rifle Pit #1 will result in no rise to the WSE during the 100-yr flood. Furthermore, the proposed Rifle Pit #1 is also outside of the estimated floodway which satisfies requirements of GCLUR Sections 3-301 and 4-203 (O). An earthen berm built at 2H:1V slope to a height of 5-ft above ground elevation, seeded with native vegetation blend and stabilized with erosion control blankets surrounding the proposed Rifle Pit #1 will withstand the hydrostatic and hydrodynamic stresses during the 100-yr flood. If you have any questions, please contact Chip Fisher at 303-746-2549 or chipf@sgm-inc.com. Sincerely, Richard (Chip) Fisher, PE Water Resources Engineer Appendices: Appendix A – HEC-RAS Modeling Results www.sgm-inc.com Appendix A www.sgm-inc.com HEC-RAS Plan: Existing2 River: Colorado River Reach: Site 1 Profile: PF 1 Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) Site 1 30902.14 PF 1 34900.0 5404.0 5412.3 5412.5 0.0 4.99 14256.0 2639.3 0.31 Site 1 29650.64 PF 1 34900.0 5400.0 5409.4 5406.4 5410.7 0.0 9.17 3806.1 431.7 0.54 Site 1 29500 Bridge Site 1 29427.62 PF 1 34900.0 5400.0 5406.2 5406.2 5409.1 0.0 13.76 2536.7 435.3 1.00 Site 1 27494.84 PF 1 34900.0 5394.0 5400.4 5400.8 0.0 5.83 9099.6 1989.1 0.42 Site 1 26255.61 PF 1 34900.0 5390.5 5397.1 5397.8 0.0 7.92 7603.5 2397.0 0.60 Site 1 25219.46 PF 1 34900.0 5388.0 5393.1 5393.6 0.0 7.78 8065.2 2482.7 0.64 Site 1 24101.01 PF 1 34900.0 5384.0 5389.9 5390.2 0.0 5.54 10742.4 3287.2 0.45 Site 1 22688.22 PF 1 34900.0 5380.8 5385.4 5385.8 0.0 6.93 11072.7 4549.1 0.63 Site 1 20730.67 PF 1 34900.0 5374.9 5379.1 5379.3 0.0 5.19 11372.2 3465.4 0.49 Site 1 19398.23 PF 1 34900.0 5372.0 5375.5 5375.7 0.0 4.14 13616.5 4038.0 0.43 Site 1 17708.26 PF 1 34900.0 5366.0 5371.8 5372.0 0.0 4.90 10922.9 2547.9 0.44 Site 1 15834.35 PF 1 34900.0 5361.9 5365.6 5366.1 0.0 5.93 6972.2 2816.5 0.61 Site 1 13915.69 PF 1 34900.0 5353.8 5359.6 5358.1 5359.9 0.0 4.86 8147.4 2500.3 0.44 Plan: Existing2 Colorado River Site 1 RS: 30902.14 Profile: PF 1 E.G. Elev (ft) 5412.53 Element Left OB Channel Right OB Vel Head (ft) 0.19 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5412.34 Reach Len. (ft) 1356.00 1251.50 946.00 Crit W.S. (ft) Flow Area (sq ft) 7438.50 2950.46 3866.98 E.G. Slope (ft/ft) 0.000837 Area (sq ft) 7438.50 2950.46 3866.98 Q Total (cfs) 34900.00 Flow (cfs) 13152.40 14721.71 7025.89 Top Width (ft) 2639.26 Top Width (ft) 1521.88 360.17 757.21 Vel Total (ft/s) 2.45 Avg. Vel. (ft/s) 1.77 4.99 1.82 Max Chl Dpth (ft) 8.34 Hydr. Depth (ft) 4.89 8.19 5.11 Conv. Total (cfs) 1206009.0 Conv. (cfs) 454496.1 508725.5 242787.5 Length Wtd. (ft) 1240.44 Wetted Per. (ft) 1523.23 360.49 760.21 Min Ch El (ft) 5404.00 Shear (lb/sq ft) 0.26 0.43 0.27 Alpha 2.06 Stream Power (lb/ft s) 0.45 2.14 0.48 Frctn Loss (ft) 1.69 Cum Volume (acre-ft) 2259.83 1241.74 88.17 C & E Loss (ft) 0.11 Cum SA (acres) 748.32 300.04 20.11 Plan: Existing2 Colorado River Site 1 RS: 29650.64 Profile: PF 1 E.G. Elev (ft) 5410.73 Element Left OB Channel Right OB Vel Head (ft) 1.31 Wt. n-Val. 0.035 W.S. Elev (ft) 5409.43 Reach Len. (ft) 10.00 10.00 10.00 Crit W.S. (ft) 5406.35 Flow Area (sq ft) 3806.14 E.G. Slope (ft/ft) 0.002587 Area (sq ft) 3806.14 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 431.69 Top Width (ft) 431.69 Vel Total (ft/s) 9.17 Avg. Vel. (ft/s) 9.17 Max Chl Dpth (ft) 9.42 Hydr. Depth (ft) 8.82 Conv. Total (cfs) 686135.0 Conv. (cfs) 686135.0 Length Wtd. (ft) 10.00 Wetted Per. (ft) 435.00 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 1.41 Alpha 1.00 Stream Power (lb/ft s) 12.96 Frctn Loss (ft) 0.03 Cum Volume (acre-ft) 2144.05 1144.68 46.18 C & E Loss (ft) 0.05 Cum SA (acres) 724.64 288.67 11.89 Plan: Existing2 Colorado River Site 1 RS: 29500 BR U Profile: PF 1 E.G. Elev (ft) 5410.65 Element Left OB Channel Right OB Vel Head (ft) 1.47 Wt. n-Val. 0.035 W.S. Elev (ft) 5409.19 Reach Len. (ft) 195.00 195.00 195.00 Crit W.S. (ft) 5406.53 Flow Area (sq ft) 3593.16 E.G. Slope (ft/ft) 0.003544 Area (sq ft) 3593.16 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 418.62 Top Width (ft) 418.62 Vel Total (ft/s) 9.71 Avg. Vel. (ft/s) 9.71 Max Chl Dpth (ft) 9.19 Hydr. Depth (ft) 8.58 Conv. Total (cfs) 586246.7 Conv. (cfs) 586246.7 Length Wtd. (ft) 195.00 Wetted Per. (ft) 476.94 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 1.67 Alpha 1.00 Stream Power (lb/ft s) 16.19 Frctn Loss (ft) 0.93 Cum Volume (acre-ft) 2144.05 1143.83 46.18 C & E Loss (ft) 0.21 Cum SA (acres) 724.64 288.57 11.89 Plan: Existing2 Colorado River Site 1 RS: 29500 BR D Profile: PF 1 E.G. Elev (ft) 5409.51 Element Left OB Channel Right OB Vel Head (ft) 2.16 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5407.36 Reach Len. (ft) 18.02 18.02 18.02 Crit W.S. (ft) 5406.34 Flow Area (sq ft) 2.21 2963.34 E.G. Slope (ft/ft) 0.006786 Area (sq ft) 2.21 2963.34 Q Total (cfs) 34900.00 Flow (cfs) 0.77 34899.23 Top Width (ft) 461.64 Top Width (ft) 28.22 433.42 Vel Total (ft/s) 11.77 Avg. Vel. (ft/s) 0.35 11.78 Max Chl Dpth (ft) 7.36 Hydr. Depth (ft) 0.08 6.84 Conv. Total (cfs) 423673.1 Conv. (cfs) 9.3 423663.8 Length Wtd. (ft) 18.02 Wetted Per. (ft) 28.41 479.53 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 0.03 2.62 Alpha 1.00 Stream Power (lb/ft s) 0.01 30.83 Frctn Loss (ft) 0.15 Cum Volume (acre-ft) 2144.04 1129.16 46.18 C & E Loss (ft) 0.24 Cum SA (acres) 724.57 286.66 11.89 Plan: Existing2 Colorado River Site 1 RS: 29427.62 Profile: PF 1 E.G. Elev (ft) 5409.13 Element Left OB Channel Right OB Vel Head (ft) 2.94 Wt. n-Val. 0.035 W.S. Elev (ft) 5406.19 Reach Len. (ft) 1192.00 1932.78 2126.00 Crit W.S. (ft) 5406.19 Flow Area (sq ft) 2536.74 E.G. Slope (ft/ft) 0.010064 Area (sq ft) 2536.74 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 435.26 Top Width (ft) 435.26 Vel Total (ft/s) 13.76 Avg. Vel. (ft/s) 13.76 Max Chl Dpth (ft) 6.19 Hydr. Depth (ft) 5.83 Conv. Total (cfs) 347881.4 Conv. (cfs) 347881.4 Length Wtd. (ft) 1821.69 Wetted Per. (ft) 436.95 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 3.65 Alpha 1.00 Stream Power (lb/ft s) 50.18 Frctn Loss (ft) 6.26 Cum Volume (acre-ft) 2144.04 1128.02 46.18 C & E Loss (ft) 1.28 Cum SA (acres) 724.57 286.48 11.89 Plan: Existing2 Colorado River Site 1 RS: 27494.84 Profile: PF 1 E.G. Elev (ft) 5400.76 Element Left OB Channel Right OB Vel Head (ft) 0.39 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5400.37 Reach Len. (ft) 1158.00 1239.23 1263.00 Crit W.S. (ft) Flow Area (sq ft) 4894.15 4186.94 18.54 E.G. Slope (ft/ft) 0.001716 Area (sq ft) 4894.15 4186.94 18.54 Q Total (cfs) 34900.00 Flow (cfs) 10474.15 24399.92 25.93 Top Width (ft) 1989.06 Top Width (ft) 1287.26 693.72 8.08 Vel Total (ft/s) 3.84 Avg. Vel. (ft/s) 2.14 5.83 1.40 Max Chl Dpth (ft) 6.46 Hydr. Depth (ft) 3.80 6.04 2.29 Conv. Total (cfs) 842407.4 Conv. (cfs) 252822.3 588959.2 625.9 Length Wtd. (ft) 1214.79 Wetted Per. (ft) 1289.19 694.23 9.24 Min Ch El (ft) 5394.00 Shear (lb/sq ft) 0.41 0.65 0.21 Alpha 1.71 Stream Power (lb/ft s) 0.87 3.77 0.30 Frctn Loss (ft) 2.92 Cum Volume (acre-ft) 2077.08 978.85 45.72 C & E Loss (ft) 0.03 Cum SA (acres) 706.95 261.44 11.69 Plan: Existing2 Colorado River Site 1 RS: 26255.61 Profile: PF 1 E.G. Elev (ft) 5397.81 Element Left OB Channel Right OB Vel Head (ft) 0.71 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5397.10 Reach Len. (ft) 1050.00 1036.15 981.00 Crit W.S. (ft) Flow Area (sq ft) 4528.64 3074.86 E.G. Slope (ft/ft) 0.003607 Area (sq ft) 4528.64 3074.86 Q Total (cfs) 34900.00 Flow (cfs) 10531.85 24368.15 Top Width (ft) 2397.04 Top Width (ft) 1836.69 560.35 Vel Total (ft/s) 4.59 Avg. Vel. (ft/s) 2.33 7.92 Max Chl Dpth (ft) 6.57 Hydr. Depth (ft) 2.47 5.49 Conv. Total (cfs) 581124.2 Conv. (cfs) 175367.1 405757.1 Length Wtd. (ft) 1035.04 Wetted Per. (ft) 1837.99 561.12 Min Ch El (ft) 5390.53 Shear (lb/sq ft) 0.55 1.23 Alpha 2.16 Stream Power (lb/ft s) 1.29 9.78 Frctn Loss (ft) 4.11 Cum Volume (acre-ft) 1951.83 875.56 45.46 C & E Loss (ft) 0.05 Cum SA (acres) 665.43 243.60 11.57 Plan: Existing2 Colorado River Site 1 RS: 25219.46 Profile: PF 1 E.G. Elev (ft) 5393.65 Element Left OB Channel Right OB Vel Head (ft) 0.53 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5393.12 Reach Len. (ft) 1167.00 1118.45 1053.00 Crit W.S. (ft) Flow Area (sq ft) 3974.24 2161.75 1929.18 E.G. Slope (ft/ft) 0.004389 Area (sq ft) 3974.24 2161.75 1929.18 Q Total (cfs) 34900.00 Flow (cfs) 11213.86 16815.01 6871.13 Top Width (ft) 2482.74 Top Width (ft) 1534.97 469.76 478.00 Vel Total (ft/s) 4.33 Avg. Vel. (ft/s) 2.82 7.78 3.56 Max Chl Dpth (ft) 7.12 Hydr. Depth (ft) 2.59 4.60 4.04 Conv. Total (cfs) 526778.8 Conv. (cfs) 169261.4 253804.9 103712.5 Length Wtd. (ft) 1129.41 Wetted Per. (ft) 1536.54 470.06 478.67 Min Ch El (ft) 5388.00 Shear (lb/sq ft) 0.71 1.26 1.10 Alpha 1.83 Stream Power (lb/ft s) 2.00 9.80 3.93 Frctn Loss (ft) 3.42 Cum Volume (acre-ft) 1849.35 813.28 23.73 C & E Loss (ft) 0.07 Cum SA (acres) 624.79 231.35 6.19 Plan: Existing2 Colorado River Site 1 RS: 24101.01 Profile: PF 1 E.G. Elev (ft) 5390.16 Element Left OB Channel Right OB Vel Head (ft) 0.31 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5389.85 Reach Len. (ft) 1473.00 1412.79 1111.00 Crit W.S. (ft) Flow Area (sq ft) 6932.86 3805.82 3.76 E.G. Slope (ft/ft) 0.002215 Area (sq ft) 6932.86 3805.82 3.76 Q Total (cfs) 34900.00 Flow (cfs) 13813.37 21083.22 3.42 Top Width (ft) 3287.24 Top Width (ft) 2460.70 822.80 3.74 Vel Total (ft/s) 3.25 Avg. Vel. (ft/s) 1.99 5.54 0.91 Max Chl Dpth (ft) 6.10 Hydr. Depth (ft) 2.82 4.63 1.01 Conv. Total (cfs) 741518.9 Conv. (cfs) 293492.1 447954.2 72.6 Length Wtd. (ft) 1444.68 Wetted Per. (ft) 2461.74 824.44 4.33 Min Ch El (ft) 5383.97 Shear (lb/sq ft) 0.39 0.64 0.12 Alpha 1.91 Stream Power (lb/ft s) 0.78 3.54 0.11 Frctn Loss (ft) 4.42 Cum Volume (acre-ft) 1703.25 736.66 0.37 C & E Loss (ft) 0.00 Cum SA (acres) 571.27 214.75 0.37 Plan: Existing2 Colorado River Site 1 RS: 22688.22 Profile: PF 1 E.G. Elev (ft) 5385.75 Element Left OB Channel Right OB Vel Head (ft) 0.31 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5385.44 Reach Len. (ft) 1763.00 1957.55 2135.00 Crit W.S. (ft) Flow Area (sq ft) 9381.75 1689.59 1.40 E.G. Slope (ft/ft) 0.004503 Area (sq ft) 9381.75 1689.59 1.40 Q Total (cfs) 34900.00 Flow (cfs) 23183.79 11714.82 1.40 Top Width (ft) 4549.10 Top Width (ft) 4103.38 444.13 1.59 Vel Total (ft/s) 3.15 Avg. Vel. (ft/s) 2.47 6.93 1.00 Max Chl Dpth (ft) 5.44 Hydr. Depth (ft) 2.29 3.80 0.88 Conv. Total (cfs) 520111.4 Conv. (cfs) 345505.8 174584.8 20.9 Length Wtd. (ft) 1819.93 Wetted Per. (ft) 4105.57 444.97 2.37 Min Ch El (ft) 5380.75 Shear (lb/sq ft) 0.64 1.07 0.17 Alpha 2.03 Stream Power (lb/ft s) 1.59 7.40 0.17 Frctn Loss (ft) 6.43 Cum Volume (acre-ft) 1427.41 647.55 0.30 C & E Loss (ft) 0.04 Cum SA (acres) 460.29 194.21 0.30 Plan: Existing2 Colorado River Site 1 RS: 20730.67 Profile: PF 1 E.G. Elev (ft) 5379.29 Element Left OB Channel Right OB Vel Head (ft) 0.19 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5379.10 Reach Len. (ft) 1430.00 1332.44 1200.00 Crit W.S. (ft) Flow Area (sq ft) 9692.43 1678.11 1.66 E.G. Slope (ft/ft) 0.002843 Area (sq ft) 9692.43 1678.11 1.66 Q Total (cfs) 34900.00 Flow (cfs) 26195.08 8703.58 1.34 Top Width (ft) 3465.37 Top Width (ft) 2979.13 483.75 2.48 Vel Total (ft/s) 3.07 Avg. Vel. (ft/s) 2.70 5.19 0.81 Max Chl Dpth (ft) 7.10 Hydr. Depth (ft) 3.25 3.47 0.67 Conv. Total (cfs) 654494.4 Conv. (cfs) 491247.3 163221.9 25.1 Length Wtd. (ft) 1407.83 Wetted Per. (ft) 2981.29 483.92 2.76 Min Ch El (ft) 5374.88 Shear (lb/sq ft) 0.58 0.62 0.11 Alpha 1.29 Stream Power (lb/ft s) 1.56 3.19 0.09 Frctn Loss (ft) 3.60 Cum Volume (acre-ft) 1041.41 571.88 0.23 C & E Loss (ft) 0.02 Cum SA (acres) 316.96 173.36 0.20 Plan: Existing2 Colorado River Site 1 RS: 19398.23 Profile: PF 1 E.G. Elev (ft) 5375.67 Element Left OB Channel Right OB Vel Head (ft) 0.12 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5375.54 Reach Len. (ft) 1603.00 1689.97 1773.00 Crit W.S. (ft) Flow Area (sq ft) 11887.98 1726.70 1.83 E.G. Slope (ft/ft) 0.002315 Area (sq ft) 11887.98 1726.70 1.83 Q Total (cfs) 34900.00 Flow (cfs) 27747.05 7151.50 1.46 Top Width (ft) 4038.04 Top Width (ft) 3438.84 597.33 1.87 Vel Total (ft/s) 2.56 Avg. Vel. (ft/s) 2.33 4.14 0.80 Max Chl Dpth (ft) 7.57 Hydr. Depth (ft) 3.46 2.89 0.98 Conv. Total (cfs) 725334.6 Conv. (cfs) 576673.2 148631.1 30.3 Length Wtd. (ft) 1627.88 Wetted Per. (ft) 3443.19 598.09 2.66 Min Ch El (ft) 5372.00 Shear (lb/sq ft) 0.50 0.42 0.10 Alpha 1.19 Stream Power (lb/ft s) 1.16 1.73 0.08 Frctn Loss (ft) 3.64 Cum Volume (acre-ft) 687.19 519.80 0.18 C & E Loss (ft) 0.01 Cum SA (acres) 211.62 156.83 0.14 Plan: Existing2 Colorado River Site 1 RS: 17708.26 Profile: PF 1 E.G. Elev (ft) 5372.02 Element Left OB Channel Right OB Vel Head (ft) 0.21 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5371.81 Reach Len. (ft) 2036.00 1873.91 2008.00 Crit W.S. (ft) Flow Area (sq ft) 8307.43 2613.22 2.28 E.G. Slope (ft/ft) 0.002164 Area (sq ft) 8307.43 2613.22 2.28 Q Total (cfs) 34900.00 Flow (cfs) 22085.83 12812.57 1.60 Top Width (ft) 2547.92 Top Width (ft) 1878.96 667.70 1.26 Vel Total (ft/s) 3.20 Avg. Vel. (ft/s) 2.66 4.90 0.70 Max Chl Dpth (ft) 7.78 Hydr. Depth (ft) 4.42 3.91 1.81 Conv. Total (cfs) 750235.0 Conv. (cfs) 474772.6 275428.0 34.4 Length Wtd. (ft) 1932.91 Wetted Per. (ft) 1880.55 668.06 3.82 Min Ch El (ft) 5366.00 Shear (lb/sq ft) 0.60 0.53 0.08 Alpha 1.30 Stream Power (lb/ft s) 1.59 2.59 0.06 Frctn Loss (ft) 5.89 Cum Volume (acre-ft) 315.59 435.62 0.10 C & E Loss (ft) 0.03 Cum SA (acres) 113.77 132.29 0.07 Plan: Existing2 Colorado River Site 1 RS: 15834.35 Profile: PF 1 E.G. Elev (ft) 5366.10 Element Left OB Channel Right OB Vel Head (ft) 0.50 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5365.60 Reach Len. (ft) 2339.00 1918.66 1085.00 Crit W.S. (ft) Flow Area (sq ft) 1642.86 5329.35 E.G. Slope (ft/ft) 0.004607 Area (sq ft) 1642.86 5329.35 Q Total (cfs) 34900.00 Flow (cfs) 3321.21 31578.79 Top Width (ft) 2816.48 Top Width (ft) 1011.20 1805.29 Vel Total (ft/s) 5.01 Avg. Vel. (ft/s) 2.02 5.93 Max Chl Dpth (ft) 3.69 Hydr. Depth (ft) 1.62 2.95 Conv. Total (cfs) 514208.8 Conv. (cfs) 48934.0 465274.9 Length Wtd. (ft) 1952.79 Wetted Per. (ft) 1011.76 1807.23 Min Ch El (ft) 5361.91 Shear (lb/sq ft) 0.47 0.85 Alpha 1.28 Stream Power (lb/ft s) 0.94 5.03 Frctn Loss (ft) 6.10 Cum Volume (acre-ft) 83.05 264.78 0.04 C & E Loss (ft) 0.05 Cum SA (acres) 46.23 79.09 0.05 Plan: Existing2 Colorado River Site 1 RS: 13915.69 Profile: PF 1 E.G. Elev (ft) 5359.95 Element Left OB Channel Right OB Vel Head (ft) 0.35 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5359.60 Reach Len. (ft) Crit W.S. (ft) 5358.08 Flow Area (sq ft) 1450.64 6693.24 3.56 E.G. Slope (ft/ft) 0.002255 Area (sq ft) 1450.64 6693.24 3.56 Q Total (cfs) 34900.00 Flow (cfs) 2353.24 32543.53 3.23 Top Width (ft) 2500.29 Top Width (ft) 710.56 1786.08 3.65 Vel Total (ft/s) 4.28 Avg. Vel. (ft/s) 1.62 4.86 0.91 Max Chl Dpth (ft) 5.85 Hydr. Depth (ft) 2.04 3.75 0.98 Conv. Total (cfs) 734918.6 Conv. (cfs) 49554.1 685296.4 68.1 Length Wtd. (ft) Wetted Per. (ft) 710.60 1787.16 4.16 Min Ch El (ft) 5353.75 Shear (lb/sq ft) 0.29 0.53 0.12 Alpha 1.21 Stream Power (lb/ft s) 0.47 2.56 0.11 Frctn Loss (ft) Cum Volume (acre-ft) C & E Loss (ft) Cum SA (acres) 0 500 1000 1500 2000 2500 3000 3500 5404 5406 5408 5410 5412 5414 5416 5418 5420 5422 Colorado River Plan: Existing2 5/14/2020 RS = 30902.14 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5402 5404 5406 5408 5410 5412 5414 5416 Colorado River Plan: Existing2 5/14/2020 RS = 29650.64 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5405 5410 5415 5420 Colorado River Plan: Existing2 5/14/2020 RS = 29500 BR I-70 Bridge over Colorado River Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5402 5404 5406 5408 5410 5412 5414 5416 5418 Colorado River Plan: Existing2 5/14/2020 RS = 29500 BR I-70 Bridge over Colorado River Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5402 5404 5406 5408 5410 5412 5414 Colorado River Plan: Existing2 5/14/2020 RS = 29427.62 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 500 1000 1500 2000 2500 5390 5400 5410 5420 5430 5440 5450 Colorado River Plan: Existing2 5/14/2020 RS = 27494.84 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 500 1000 1500 2000 2500 3000 3500 5390 5400 5410 5420 5430 5440 Colorado River Plan: Existing2 5/14/2020 RS = 26255.61 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5380 5390 5400 5410 5420 5430 Colorado River Plan: Existing2 5/14/2020 RS = 25219.46 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 5380 5390 5400 5410 5420 5430 Colorado River Plan: Existing2 5/14/2020 RS = 24101.01 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 5380 5390 5400 5410 5420 5430 Colorado River Plan: Existing2 5/14/2020 RS = 22688.22 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 5370 5380 5390 5400 5410 5420 5430 5440 Colorado River Plan: Existing2 5/14/2020 RS = 20730.67 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 7000 5360 5370 5380 5390 5400 5410 5420 5430 Colorado River Plan: Existing2 5/14/2020 RS = 19398.23 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 7000 5350 5360 5370 5380 5390 5400 5410 5420 5430 Colorado River Plan: Existing2 5/14/2020 RS = 17708.26 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 5360 5365 5370 5375 5380 5385 Colorado River Plan: Existing2 5/14/2020 RS = 15834.35 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 . 0 7 0 1000 2000 3000 4000 5350 5355 5360 5365 5370 5375 5380 5385 5390 Colorado River Plan: Existing2 5/14/2020 RS = 13915.69 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 . 0 7 HEC-RAS Plan: Proposed2 River: Colorado River Reach: Site 1 Profile: PF 1 Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) Site 1 30902.14 PF 1 34900.0 5404.0 5412.3 5412.5 0.0 5.00 14244.1 2641.0 0.31 Site 1 29650.64 PF 1 34900.0 5400.0 5409.4 5406.4 5410.7 0.0 9.17 3806.1 431.7 0.54 Site 1 29500 Bridge Site 1 29427.62 PF 1 34900.0 5400.0 5406.2 5406.2 5409.1 0.0 13.75 2538.0 435.3 1.00 Site 1 27494.84 PF 1 34900.0 5394.0 5400.4 5400.8 0.0 5.85 9057.0 1988.9 0.42 Site 1 26255.61 PF 1 34900.0 5390.5 5397.1 5397.8 0.0 7.93 7604.5 2396.3 0.60 Site 1 25219.46 PF 1 34900.0 5388.0 5393.1 5393.6 0.0 7.80 8060.1 2481.8 0.64 Site 1 24101.01 PF 1 34900.0 5384.0 5389.9 5390.2 0.0 5.53 10767.1 3290.2 0.45 Site 1 22688.22 PF 1 34900.0 5380.8 5385.4 5385.8 0.0 6.95 10118.4 3654.6 0.63 Site 1 20730.67 PF 1 34900.0 5374.9 5379.1 5379.3 0.0 5.18 11396.7 3505.0 0.49 Site 1 19398.23 PF 1 34900.0 5372.0 5375.5 5375.6 0.0 4.12 13583.7 4022.9 0.43 Site 1 17708.26 PF 1 34900.0 5366.0 5371.8 5372.0 0.0 4.87 10968.8 2550.1 0.43 Site 1 15834.35 PF 1 34900.0 5361.9 5365.6 5366.1 0.0 5.93 6965.2 2814.3 0.61 Site 1 13915.69 PF 1 34900.0 5353.7 5359.6 5358.1 5359.9 0.0 4.86 8149.5 2491.9 0.44 Plan: Proposed2 Colorado River Site 1 RS: 30902.14 Profile: PF 1 E.G. Elev (ft) 5412.53 Element Left OB Channel Right OB Vel Head (ft) 0.19 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5412.34 Reach Len. (ft) 1356.00 1251.50 946.00 Crit W.S. (ft) Flow Area (sq ft) 7426.19 2950.85 3867.08 E.G. Slope (ft/ft) 0.000840 Area (sq ft) 7426.19 2950.85 3867.08 Q Total (cfs) 34900.00 Flow (cfs) 13121.90 14743.20 7034.90 Top Width (ft) 2641.05 Top Width (ft) 1523.66 360.17 757.21 Vel Total (ft/s) 2.45 Avg. Vel. (ft/s) 1.77 5.00 1.82 Max Chl Dpth (ft) 8.34 Hydr. Depth (ft) 4.87 8.19 5.11 Conv. Total (cfs) 1204513.0 Conv. (cfs) 452879.5 508836.0 242797.4 Length Wtd. (ft) 1240.36 Wetted Per. (ft) 1525.06 360.49 760.22 Min Ch El (ft) 5404.00 Shear (lb/sq ft) 0.26 0.43 0.27 Alpha 2.06 Stream Power (lb/ft s) 0.45 2.14 0.49 Frctn Loss (ft) 1.69 Cum Volume (acre-ft) 2226.64 1240.44 87.86 C & E Loss (ft) 0.11 Cum SA (acres) 715.85 300.03 20.12 Plan: Proposed2 Colorado River Site 1 RS: 29650.64 Profile: PF 1 E.G. Elev (ft) 5410.73 Element Left OB Channel Right OB Vel Head (ft) 1.31 Wt. n-Val. 0.035 W.S. Elev (ft) 5409.43 Reach Len. (ft) 10.00 10.00 10.00 Crit W.S. (ft) 5406.35 Flow Area (sq ft) 3806.14 E.G. Slope (ft/ft) 0.002587 Area (sq ft) 3806.14 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 431.69 Top Width (ft) 431.69 Vel Total (ft/s) 9.17 Avg. Vel. (ft/s) 9.17 Max Chl Dpth (ft) 9.42 Hydr. Depth (ft) 8.82 Conv. Total (cfs) 686135.0 Conv. (cfs) 686135.0 Length Wtd. (ft) 10.00 Wetted Per. (ft) 435.00 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 1.41 Alpha 1.00 Stream Power (lb/ft s) 12.96 Frctn Loss (ft) 0.03 Cum Volume (acre-ft) 2111.05 1143.37 45.87 C & E Loss (ft) 0.05 Cum SA (acres) 692.14 288.66 11.90 Plan: Proposed2 Colorado River Site 1 RS: 29500 BR U Profile: PF 1 E.G. Elev (ft) 5410.65 Element Left OB Channel Right OB Vel Head (ft) 1.47 Wt. n-Val. 0.035 W.S. Elev (ft) 5409.19 Reach Len. (ft) 195.00 195.00 195.00 Crit W.S. (ft) 5406.53 Flow Area (sq ft) 3593.16 E.G. Slope (ft/ft) 0.003544 Area (sq ft) 3593.16 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 418.62 Top Width (ft) 418.62 Vel Total (ft/s) 9.71 Avg. Vel. (ft/s) 9.71 Max Chl Dpth (ft) 9.19 Hydr. Depth (ft) 8.58 Conv. Total (cfs) 586246.7 Conv. (cfs) 586246.7 Length Wtd. (ft) 195.00 Wetted Per. (ft) 476.94 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 1.67 Alpha 1.00 Stream Power (lb/ft s) 16.19 Frctn Loss (ft) 0.93 Cum Volume (acre-ft) 2111.05 1142.52 45.87 C & E Loss (ft) 0.21 Cum SA (acres) 692.14 288.56 11.90 Plan: Proposed2 Colorado River Site 1 RS: 29500 BR D Profile: PF 1 E.G. Elev (ft) 5409.51 Element Left OB Channel Right OB Vel Head (ft) 2.16 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5407.36 Reach Len. (ft) 18.02 18.02 18.02 Crit W.S. (ft) 5406.34 Flow Area (sq ft) 2.10 2961.65 E.G. Slope (ft/ft) 0.006797 Area (sq ft) 2.10 2961.65 Q Total (cfs) 34900.00 Flow (cfs) 0.72 34899.28 Top Width (ft) 460.53 Top Width (ft) 27.15 433.38 Vel Total (ft/s) 11.78 Avg. Vel. (ft/s) 0.34 11.78 Max Chl Dpth (ft) 7.35 Hydr. Depth (ft) 0.08 6.83 Conv. Total (cfs) 423303.0 Conv. (cfs) 8.8 423294.2 Length Wtd. (ft) 18.02 Wetted Per. (ft) 27.34 479.47 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 0.03 2.62 Alpha 1.00 Stream Power (lb/ft s) 0.01 30.89 Frctn Loss (ft) 0.15 Cum Volume (acre-ft) 2111.05 1127.85 45.87 C & E Loss (ft) 0.23 Cum SA (acres) 692.08 286.65 11.90 Plan: Proposed2 Colorado River Site 1 RS: 29427.62 Profile: PF 1 E.G. Elev (ft) 5409.13 Element Left OB Channel Right OB Vel Head (ft) 2.94 Wt. n-Val. 0.035 W.S. Elev (ft) 5406.19 Reach Len. (ft) 1192.00 1932.78 2126.00 Crit W.S. (ft) 5406.19 Flow Area (sq ft) 2538.02 E.G. Slope (ft/ft) 0.010048 Area (sq ft) 2538.02 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 435.29 Top Width (ft) 435.29 Vel Total (ft/s) 13.75 Avg. Vel. (ft/s) 13.75 Max Chl Dpth (ft) 6.19 Hydr. Depth (ft) 5.83 Conv. Total (cfs) 348159.0 Conv. (cfs) 348159.0 Length Wtd. (ft) 1822.27 Wetted Per. (ft) 436.98 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 3.64 Alpha 1.00 Stream Power (lb/ft s) 50.10 Frctn Loss (ft) 6.32 Cum Volume (acre-ft) 2111.05 1126.71 45.87 C & E Loss (ft) 1.27 Cum SA (acres) 692.07 286.47 11.90 Plan: Proposed2 Colorado River Site 1 RS: 27494.84 Profile: PF 1 E.G. Elev (ft) 5400.76 Element Left OB Channel Right OB Vel Head (ft) 0.39 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5400.36 Reach Len. (ft) 1158.00 1239.23 1263.00 Crit W.S. (ft) Flow Area (sq ft) 4861.16 4177.35 18.47 E.G. Slope (ft/ft) 0.001737 Area (sq ft) 4861.16 4177.35 18.47 Q Total (cfs) 34900.00 Flow (cfs) 10420.06 24453.99 25.95 Top Width (ft) 1988.92 Top Width (ft) 1287.13 693.72 8.07 Vel Total (ft/s) 3.85 Avg. Vel. (ft/s) 2.14 5.85 1.41 Max Chl Dpth (ft) 6.45 Hydr. Depth (ft) 3.78 6.02 2.29 Conv. Total (cfs) 837333.6 Conv. (cfs) 250001.9 586709.1 622.6 Length Wtd. (ft) 1214.72 Wetted Per. (ft) 1289.08 694.24 9.23 Min Ch El (ft) 5394.00 Shear (lb/sq ft) 0.41 0.65 0.22 Alpha 1.71 Stream Power (lb/ft s) 0.88 3.82 0.30 Frctn Loss (ft) 2.95 Cum Volume (acre-ft) 2044.53 977.73 45.42 C & E Loss (ft) 0.03 Cum SA (acres) 674.46 261.42 11.70 Plan: Proposed2 Colorado River Site 1 RS: 26255.61 Profile: PF 1 E.G. Elev (ft) 5397.78 Element Left OB Channel Right OB Vel Head (ft) 0.71 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5397.07 Reach Len. (ft) 1050.00 1036.15 981.00 Crit W.S. (ft) Flow Area (sq ft) 4547.55 3056.94 E.G. Slope (ft/ft) 0.003637 Area (sq ft) 4547.55 3056.94 Q Total (cfs) 34900.00 Flow (cfs) 10650.84 24249.15 Top Width (ft) 2396.30 Top Width (ft) 1836.46 559.84 Vel Total (ft/s) 4.59 Avg. Vel. (ft/s) 2.34 7.93 Max Chl Dpth (ft) 6.54 Hydr. Depth (ft) 2.48 5.46 Conv. Total (cfs) 578683.9 Conv. (cfs) 176603.8 402080.1 Length Wtd. (ft) 1035.12 Wetted Per. (ft) 1837.77 560.58 Min Ch El (ft) 5390.53 Shear (lb/sq ft) 0.56 1.24 Alpha 2.16 Stream Power (lb/ft s) 1.32 9.82 Frctn Loss (ft) 4.10 Cum Volume (acre-ft) 1919.47 874.83 45.16 C & E Loss (ft) 0.05 Cum SA (acres) 632.94 243.59 11.58 Plan: Proposed2 Colorado River Site 1 RS: 25219.46 Profile: PF 1 E.G. Elev (ft) 5393.63 Element Left OB Channel Right OB Vel Head (ft) 0.54 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5393.09 Reach Len. (ft) 1167.00 1118.45 1053.00 Crit W.S. (ft) Flow Area (sq ft) 3947.71 2196.65 1915.77 E.G. Slope (ft/ft) 0.004325 Area (sq ft) 3947.71 2196.65 1915.77 Q Total (cfs) 34900.00 Flow (cfs) 11015.23 17142.44 6742.32 Top Width (ft) 2481.76 Top Width (ft) 1534.07 469.76 477.93 Vel Total (ft/s) 4.33 Avg. Vel. (ft/s) 2.79 7.80 3.52 Max Chl Dpth (ft) 7.09 Hydr. Depth (ft) 2.57 4.68 4.01 Conv. Total (cfs) 530694.1 Conv. (cfs) 167499.1 260670.3 102524.6 Length Wtd. (ft) 1129.40 Wetted Per. (ft) 1535.65 470.06 478.59 Min Ch El (ft) 5388.00 Shear (lb/sq ft) 0.69 1.26 1.08 Alpha 1.85 Stream Power (lb/ft s) 1.94 9.85 3.80 Frctn Loss (ft) 3.39 Cum Volume (acre-ft) 1817.09 812.35 23.58 C & E Loss (ft) 0.07 Cum SA (acres) 592.32 231.35 6.20 Plan: Proposed2 Colorado River Site 1 RS: 24101.01 Profile: PF 1 E.G. Elev (ft) 5390.18 Element Left OB Channel Right OB Vel Head (ft) 0.31 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5389.86 Reach Len. (ft) 1473.00 1412.79 1111.00 Crit W.S. (ft) Flow Area (sq ft) 6950.58 3812.73 3.74 E.G. Slope (ft/ft) 0.002201 Area (sq ft) 6950.58 3812.73 3.74 Q Total (cfs) 34900.00 Flow (cfs) 13817.05 21079.60 3.36 Top Width (ft) 3290.17 Top Width (ft) 2463.58 822.80 3.79 Vel Total (ft/s) 3.24 Avg. Vel. (ft/s) 1.99 5.53 0.90 Max Chl Dpth (ft) 6.11 Hydr. Depth (ft) 2.82 4.63 0.99 Conv. Total (cfs) 743889.4 Conv. (cfs) 294508.8 449309.1 71.5 Length Wtd. (ft) 1444.67 Wetted Per. (ft) 2464.64 824.45 4.37 Min Ch El (ft) 5383.97 Shear (lb/sq ft) 0.39 0.64 0.12 Alpha 1.91 Stream Power (lb/ft s) 0.77 3.51 0.11 Frctn Loss (ft) 4.42 Cum Volume (acre-ft) 1671.10 735.20 0.38 C & E Loss (ft) 0.00 Cum SA (acres) 538.77 214.75 0.38 Plan: Proposed2 Colorado River Site 1 RS: 22688.22 Profile: PF 1 E.G. Elev (ft) 5385.76 Element Left OB Channel Right OB Vel Head (ft) 0.33 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5385.43 Reach Len. (ft) 1763.00 1957.55 2135.00 Crit W.S. (ft) Flow Area (sq ft) 8428.58 1688.44 1.39 E.G. Slope (ft/ft) 0.004527 Area (sq ft) 8428.58 1688.44 1.39 Q Total (cfs) 34900.00 Flow (cfs) 23165.64 11732.96 1.40 Top Width (ft) 3654.56 Top Width (ft) 3208.84 444.13 1.59 Vel Total (ft/s) 3.45 Avg. Vel. (ft/s) 2.75 6.95 1.00 Max Chl Dpth (ft) 5.43 Hydr. Depth (ft) 2.63 3.80 0.88 Conv. Total (cfs) 518707.7 Conv. (cfs) 344303.6 174383.3 20.8 Length Wtd. (ft) 1819.93 Wetted Per. (ft) 3211.26 444.98 2.37 Min Ch El (ft) 5380.75 Shear (lb/sq ft) 0.74 1.07 0.17 Alpha 1.79 Stream Power (lb/ft s) 2.04 7.45 0.17 Frctn Loss (ft) 6.45 Cum Volume (acre-ft) 1411.07 645.99 0.32 C & E Loss (ft) 0.04 Cum SA (acres) 442.86 194.21 0.31 Plan: Proposed2 Colorado River Site 1 RS: 20730.67 Profile: PF 1 E.G. Elev (ft) 5379.28 Element Left OB Channel Right OB Vel Head (ft) 0.19 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5379.09 Reach Len. (ft) 1430.00 1332.44 1200.00 Crit W.S. (ft) Flow Area (sq ft) 9719.50 1675.51 1.65 E.G. Slope (ft/ft) 0.002846 Area (sq ft) 9719.50 1675.51 1.65 Q Total (cfs) 34900.00 Flow (cfs) 26213.27 8685.40 1.33 Top Width (ft) 3504.97 Top Width (ft) 3018.75 483.75 2.47 Vel Total (ft/s) 3.06 Avg. Vel. (ft/s) 2.70 5.18 0.80 Max Chl Dpth (ft) 7.09 Hydr. Depth (ft) 3.22 3.46 0.67 Conv. Total (cfs) 654172.5 Conv. (cfs) 491346.7 162800.9 24.9 Length Wtd. (ft) 1408.01 Wetted Per. (ft) 3020.93 483.92 2.75 Min Ch El (ft) 5374.88 Shear (lb/sq ft) 0.57 0.62 0.11 Alpha 1.30 Stream Power (lb/ft s) 1.54 3.19 0.09 Frctn Loss (ft) 3.62 Cum Volume (acre-ft) 1043.82 570.40 0.24 C & E Loss (ft) 0.02 Cum SA (acres) 316.84 173.36 0.21 Plan: Proposed2 Colorado River Site 1 RS: 19398.23 Profile: PF 1 E.G. Elev (ft) 5375.64 Element Left OB Channel Right OB Vel Head (ft) 0.12 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5375.52 Reach Len. (ft) 1603.00 1689.97 1773.00 Crit W.S. (ft) Flow Area (sq ft) 11874.22 1707.57 1.89 E.G. Slope (ft/ft) 0.002331 Area (sq ft) 11874.22 1707.57 1.89 Q Total (cfs) 34900.00 Flow (cfs) 27854.81 7043.63 1.56 Top Width (ft) 4022.93 Top Width (ft) 3423.81 597.33 1.80 Vel Total (ft/s) 2.57 Avg. Vel. (ft/s) 2.35 4.12 0.83 Max Chl Dpth (ft) 7.52 Hydr. Depth (ft) 3.47 2.86 1.05 Conv. Total (cfs) 722901.5 Conv. (cfs) 576970.9 145898.2 32.4 Length Wtd. (ft) 1627.56 Wetted Per. (ft) 3428.90 598.09 2.61 Min Ch El (ft) 5372.00 Shear (lb/sq ft) 0.50 0.42 0.11 Alpha 1.19 Stream Power (lb/ft s) 1.18 1.71 0.09 Frctn Loss (ft) 3.64 Cum Volume (acre-ft) 689.38 518.66 0.19 C & E Loss (ft) 0.01 Cum SA (acres) 211.09 156.82 0.15 Plan: Proposed2 Colorado River Site 1 RS: 17708.26 Profile: PF 1 E.G. Elev (ft) 5372.00 Element Left OB Channel Right OB Vel Head (ft) 0.20 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5371.79 Reach Len. (ft) 2036.00 1873.91 2008.00 Crit W.S. (ft) Flow Area (sq ft) 8365.50 2600.77 2.55 E.G. Slope (ft/ft) 0.002147 Area (sq ft) 8365.50 2600.77 2.55 Q Total (cfs) 34900.00 Flow (cfs) 22240.87 12657.13 2.01 Top Width (ft) 2550.15 Top Width (ft) 1880.85 667.70 1.60 Vel Total (ft/s) 3.18 Avg. Vel. (ft/s) 2.66 4.87 0.79 Max Chl Dpth (ft) 7.76 Hydr. Depth (ft) 4.45 3.90 1.60 Conv. Total (cfs) 753201.6 Conv. (cfs) 479995.9 273162.4 43.4 Length Wtd. (ft) 1933.27 Wetted Per. (ft) 1882.43 668.37 3.57 Min Ch El (ft) 5366.00 Shear (lb/sq ft) 0.60 0.52 0.10 Alpha 1.29 Stream Power (lb/ft s) 1.58 2.54 0.08 Frctn Loss (ft) 5.87 Cum Volume (acre-ft) 316.97 435.08 0.10 C & E Loss (ft) 0.03 Cum SA (acres) 113.48 132.29 0.08 Plan: Proposed2 Colorado River Site 1 RS: 15834.35 Profile: PF 1 E.G. Elev (ft) 5366.09 Element Left OB Channel Right OB Vel Head (ft) 0.50 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5365.59 Reach Len. (ft) 2339.00 1918.66 1085.00 Crit W.S. (ft) Flow Area (sq ft) 1639.42 5325.82 E.G. Slope (ft/ft) 0.004618 Area (sq ft) 1639.42 5325.82 Q Total (cfs) 34900.00 Flow (cfs) 3317.93 31582.07 Top Width (ft) 2814.33 Top Width (ft) 1009.07 1805.27 Vel Total (ft/s) 5.01 Avg. Vel. (ft/s) 2.02 5.93 Max Chl Dpth (ft) 3.68 Hydr. Depth (ft) 1.62 2.95 Conv. Total (cfs) 513590.6 Conv. (cfs) 48826.9 464763.8 Length Wtd. (ft) 1953.00 Wetted Per. (ft) 1009.63 1807.21 Min Ch El (ft) 5361.91 Shear (lb/sq ft) 0.47 0.85 Alpha 1.28 Stream Power (lb/ft s) 0.95 5.04 Frctn Loss (ft) 6.10 Cum Volume (acre-ft) 83.15 264.59 0.04 C & E Loss (ft) 0.05 Cum SA (acres) 45.94 79.09 0.05 Plan: Proposed2 Colorado River Site 1 RS: 13915.69 Profile: PF 1 E.G. Elev (ft) 5359.94 Element Left OB Channel Right OB Vel Head (ft) 0.34 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5359.60 Reach Len. (ft) Crit W.S. (ft) 5358.10 Flow Area (sq ft) 1457.74 6688.19 3.55 E.G. Slope (ft/ft) 0.002255 Area (sq ft) 1457.74 6688.19 3.55 Q Total (cfs) 34900.00 Flow (cfs) 2391.44 32505.35 3.22 Top Width (ft) 2491.92 Top Width (ft) 702.19 1786.08 3.64 Vel Total (ft/s) 4.28 Avg. Vel. (ft/s) 1.64 4.86 0.91 Max Chl Dpth (ft) 5.91 Hydr. Depth (ft) 2.08 3.74 0.97 Conv. Total (cfs) 734863.5 Conv. (cfs) 50354.7 684441.1 67.7 Length Wtd. (ft) Wetted Per. (ft) 702.24 1787.14 4.16 Min Ch El (ft) 5353.69 Shear (lb/sq ft) 0.29 0.53 0.12 Alpha 1.21 Stream Power (lb/ft s) 0.48 2.56 0.11 Frctn Loss (ft) Cum Volume (acre-ft) C & E Loss (ft) Cum SA (acres) 0 500 1000 1500 2000 2500 3000 3500 5404 5406 5408 5410 5412 5414 5416 5418 5420 5422 Colorado River Plan: Proposed2 5/14/2020 RS = 30902.14 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5402 5404 5406 5408 5410 5412 5414 5416 Colorado River Plan: Proposed2 5/14/2020 RS = 29650.64 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5405 5410 5415 5420 Colorado River Plan: Proposed2 5/14/2020 RS = 29500 BR I-70 Bridge over Colorado River Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5402 5404 5406 5408 5410 5412 5414 5416 5418 Colorado River Plan: Proposed2 5/14/2020 RS = 29500 BR I-70 Bridge over Colorado River Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 200 400 600 800 1000 1200 1400 5400 5402 5404 5406 5408 5410 5412 5414 Colorado River Plan: Proposed2 5/14/2020 RS = 29427.62 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 .07 0 500 1000 1500 2000 2500 5390 5400 5410 5420 5430 5440 5450 Colorado River Plan: Proposed2 5/14/2020 RS = 27494.84 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 500 1000 1500 2000 2500 3000 3500 5390 5400 5410 5420 5430 5440 Colorado River Plan: Proposed2 5/14/2020 RS = 26255.61 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5380 5390 5400 5410 5420 5430 Colorado River Plan: Proposed2 5/14/2020 RS = 25219.46 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 5380 5390 5400 5410 5420 5430 Colorado River Plan: Proposed2 5/14/2020 RS = 24101.01 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 5350 5360 5370 5380 5390 5400 5410 5420 5430 Colorado River Plan: Proposed2 5/14/2020 RS = 22688.22 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 5340 5360 5380 5400 5420 5440 Colorado River Plan: Proposed2 5/14/2020 RS = 20730.67 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 7000 5360 5370 5380 5390 5400 5410 5420 5430 Colorado River Plan: Proposed2 5/14/2020 RS = 19398.23 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 6000 7000 5350 5360 5370 5380 5390 5400 5410 5420 5430 Colorado River Plan: Proposed2 5/14/2020 RS = 17708.26 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 .07 0 1000 2000 3000 4000 5000 5360 5365 5370 5375 5380 5385 Colorado River Plan: Proposed2 5/14/2020 RS = 15834.35 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Ground Bank Sta .07 .035 . 0 7 0 1000 2000 3000 4000 5350 5355 5360 5365 5370 5375 5380 5385 5390 Colorado River Plan: Proposed2 5/14/2020 RS = 13915.69 Station (ft)Elevation (ft)Legend EG PF 1 WS PF 1 Crit PF 1 Ground Bank Sta .07 .035 . 0 7 HEC-RAS Plan: FwayM1 River: Colorado River Reach: Site 1 Reach River Sta Profile W.S. Elev Prof Delta WS E.G. Elev Top Wdth Act Q Left Q Channel Q Right Enc Sta L Ch Sta L Ch Sta R Enc Sta R (ft) (ft) (ft) (ft) (cfs) (cfs) (cfs) (ft) (ft) (ft) (ft) Site 1 30902.14 PF 1 5412.34 5412.53 2641.05 13121.90 14743.20 7034.90 1956.95 2317.12 Site 1 30902.14 PF 2 5412.85 0.50 5413.58 824.33 8160.65 24671.19 2068.16 1597.59 1956.95 2317.12 2421.92 Site 1 29650.64 PF 1 5409.43 5410.73 431.69 34900.00 336.82 798.40 Site 1 29650.64 PF 2 5409.42 0.00 5410.73 431.69 34900.00 326.82 336.82 798.40 808.41 Site 1 29500 BR U PF 1 5409.19 5410.65 418.62 34900.00 336.82 798.40 Site 1 29500 BR U PF 2 5409.19 0.00 5410.65 418.62 34900.00 326.82 336.82 798.40 808.41 Site 1 29500 BR D PF 1 5407.36 5409.51 461.09 0.75 34899.26 366.90 982.50 Site 1 29500 BR D PF 2 5407.36 0.00 5409.51 433.40 34900.00 356.90 366.90 982.50 992.50 Site 1 29427.62 PF 1 5406.19 5409.13 435.29 34900.00 366.90 982.50 Site 1 29427.62 PF 2 5406.19 0.00 5409.13 435.29 34900.00 356.90 366.90 982.50 992.50 Site 1 27494.84 PF 1 5400.36 5400.76 1988.92 10420.06 24453.99 25.95 1401.12 2094.84 Site 1 27494.84 PF 2 5400.86 0.50 5401.32 1371.76 7679.25 27187.41 33.34 731.93 1401.12 2094.84 2104.84 Site 1 26255.61 PF 1 5397.07 5397.78 2396.30 10650.84 24249.15 1974.18 2547.44 Site 1 26255.61 PF 2 5397.57 0.50 5398.42 1590.65 7356.71 27543.29 950.92 1974.18 2547.44 2557.44 Site 1 25219.46 PF 1 5393.09 5393.63 2481.76 11015.23 17142.44 6742.32 2483.80 2953.56 Site 1 25219.46 PF 2 5393.37 0.28 5394.10 1761.84 12335.27 19989.61 2575.12 1391.78 2483.80 2953.56 3153.62 Site 1 24101.01 PF 1 5389.86 5390.18 3290.17 13817.05 21079.60 3.36 3158.24 3981.04 Site 1 24101.01 PF 2 5390.36 0.50 5390.71 2391.96 11523.21 23375.09 1.70 1590.08 3158.24 3981.04 3982.04 Site 1 22688.22 PF 1 5385.43 5385.76 3654.56 23165.64 11732.96 1.40 4559.40 5003.53 Site 1 22688.22 PF 2 5385.94 0.50 5386.45 2603.56 19643.42 15253.69 2.90 2402.02 4559.40 5003.53 5018.53 Site 1 20730.67 PF 1 5379.09 5379.28 3504.97 26213.27 8685.40 1.33 4964.81 5448.56 Site 1 20730.67 PF 2 5379.59 0.50 5379.85 2135.99 24443.68 10453.36 2.96 3270.79 4964.81 5448.56 5510.56 Site 1 19398.23 PF 1 5375.52 5375.64 4022.92 27855.12 7043.32 1.56 5386.70 5984.03 Site 1 19398.23 PF 2 5376.02 0.50 5376.19 2931.68 26189.41 8710.59 3012.35 5386.70 5984.03 5944.03 Site 1 17708.26 PF 1 5371.79 5372.00 2550.16 22240.22 12657.77 2.01 5073.60 5741.30 Site 1 17708.26 PF 2 5372.30 0.50 5372.53 2153.90 19964.22 14932.92 2.86 3589.25 5073.60 5741.30 5751.30 Site 1 15834.35 PF 1 5365.59 5366.09 2814.29 3317.35 31582.65 3062.93 4872.42 Site 1 15834.35 PF 2 5365.49 -0.10 5366.21 1810.39 1.50 34898.50 3052.93 3062.93 4872.42 4882.42 Site 1 13915.69 PF 1 5359.60 5359.94 2492.14 2392.54 32504.24 3.22 1945.13 3731.21 Site 1 13915.69 PF 2 5360.10 0.50 5360.43 1800.91 26.48 34868.43 5.09 1935.13 1945.13 3731.21 3741.21 Plan: FwayM1 Colorado River Site 1 RS: 30902.14 Profile: PF 1 E.G. Elev (ft) 5412.53 Element Left OB Channel Right OB Vel Head (ft) 0.19 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5412.34 Reach Len. (ft) 1356.00 1251.50 946.00 Crit W.S. (ft) Flow Area (sq ft) 7426.19 2950.85 3867.08 E.G. Slope (ft/ft) 0.000840 Area (sq ft) 7426.19 2950.85 3867.08 Q Total (cfs) 34900.00 Flow (cfs) 13121.90 14743.20 7034.90 Top Width (ft) 2641.05 Top Width (ft) 1523.66 360.17 757.21 Vel Total (ft/s) 2.45 Avg. Vel. (ft/s) 1.77 5.00 1.82 Max Chl Dpth (ft) 8.34 Hydr. Depth (ft) 4.87 8.19 5.11 Conv. Total (cfs) 1204513.0 Conv. (cfs) 452879.5 508836.0 242797.4 Length Wtd. (ft) 1240.36 Wetted Per. (ft) 1525.06 360.49 760.22 Min Ch El (ft) 5404.00 Shear (lb/sq ft) 0.26 0.43 0.27 Alpha 2.06 Stream Power (lb/ft s) 0.45 2.14 0.49 Frctn Loss (ft) 1.69 Cum Volume (acre-ft) 2226.71 1240.51 87.86 C & E Loss (ft) 0.11 Cum SA (acres) 715.86 300.03 20.12 Plan: FwayM1 Colorado River Site 1 RS: 29650.64 Profile: PF 1 E.G. Elev (ft) 5410.73 Element Left OB Channel Right OB Vel Head (ft) 1.31 Wt. n-Val. 0.035 W.S. Elev (ft) 5409.43 Reach Len. (ft) 10.00 10.00 10.00 Crit W.S. (ft) 5406.35 Flow Area (sq ft) 3806.14 E.G. Slope (ft/ft) 0.002587 Area (sq ft) 3806.14 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 431.69 Top Width (ft) 431.69 Vel Total (ft/s) 9.17 Avg. Vel. (ft/s) 9.17 Max Chl Dpth (ft) 9.42 Hydr. Depth (ft) 8.82 Conv. Total (cfs) 686135.0 Conv. (cfs) 686135.0 Length Wtd. (ft) 10.00 Wetted Per. (ft) 435.00 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 1.41 Alpha 1.00 Stream Power (lb/ft s) 12.96 Frctn Loss (ft) 0.03 Cum Volume (acre-ft) 2111.12 1143.44 45.87 C & E Loss (ft) 0.05 Cum SA (acres) 692.14 288.66 11.90 Plan: FwayM1 Colorado River Site 1 RS: 29500 BR U Profile: PF 1 E.G. Elev (ft) 5410.65 Element Left OB Channel Right OB Vel Head (ft) 1.47 Wt. n-Val. 0.035 W.S. Elev (ft) 5409.19 Reach Len. (ft) 195.00 195.00 195.00 Crit W.S. (ft) 5406.53 Flow Area (sq ft) 3593.37 E.G. Slope (ft/ft) 0.003543 Area (sq ft) 3593.37 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 418.62 Top Width (ft) 418.62 Vel Total (ft/s) 9.71 Avg. Vel. (ft/s) 9.71 Max Chl Dpth (ft) 9.19 Hydr. Depth (ft) 8.58 Conv. Total (cfs) 586297.9 Conv. (cfs) 586297.9 Length Wtd. (ft) 195.00 Wetted Per. (ft) 476.94 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 1.67 Alpha 1.00 Stream Power (lb/ft s) 16.19 Frctn Loss (ft) 0.93 Cum Volume (acre-ft) 2111.12 1142.59 45.87 C & E Loss (ft) 0.21 Cum SA (acres) 692.14 288.56 11.90 Plan: FwayM1 Colorado River Site 1 RS: 29500 BR D Profile: PF 1 E.G. Elev (ft) 5409.51 Element Left OB Channel Right OB Vel Head (ft) 2.16 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5407.36 Reach Len. (ft) 18.02 18.02 18.02 Crit W.S. (ft) 5406.35 Flow Area (sq ft) 2.15 2962.49 E.G. Slope (ft/ft) 0.006792 Area (sq ft) 2.15 2962.49 Q Total (cfs) 34900.00 Flow (cfs) 0.75 34899.26 Top Width (ft) 461.09 Top Width (ft) 27.69 433.40 Vel Total (ft/s) 11.77 Avg. Vel. (ft/s) 0.35 11.78 Max Chl Dpth (ft) 7.36 Hydr. Depth (ft) 0.08 6.84 Conv. Total (cfs) 423488.1 Conv. (cfs) 9.0 423479.0 Length Wtd. (ft) 18.02 Wetted Per. (ft) 27.87 479.50 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 0.03 2.62 Alpha 1.00 Stream Power (lb/ft s) 0.01 30.86 Frctn Loss (ft) 0.15 Cum Volume (acre-ft) 2111.12 1127.92 45.87 C & E Loss (ft) 0.23 Cum SA (acres) 692.08 286.65 11.90 Plan: FwayM1 Colorado River Site 1 RS: 29427.62 Profile: PF 1 E.G. Elev (ft) 5409.13 Element Left OB Channel Right OB Vel Head (ft) 2.94 Wt. n-Val. 0.035 W.S. Elev (ft) 5406.19 Reach Len. (ft) 1192.00 1932.78 2126.00 Crit W.S. (ft) 5406.19 Flow Area (sq ft) 2538.02 E.G. Slope (ft/ft) 0.010048 Area (sq ft) 2538.02 Q Total (cfs) 34900.00 Flow (cfs) 34900.00 Top Width (ft) 435.29 Top Width (ft) 435.29 Vel Total (ft/s) 13.75 Avg. Vel. (ft/s) 13.75 Max Chl Dpth (ft) 6.19 Hydr. Depth (ft) 5.83 Conv. Total (cfs) 348159.0 Conv. (cfs) 348159.0 Length Wtd. (ft) 1822.27 Wetted Per. (ft) 436.98 Min Ch El (ft) 5400.00 Shear (lb/sq ft) 3.64 Alpha 1.00 Stream Power (lb/ft s) 50.10 Frctn Loss (ft) 6.32 Cum Volume (acre-ft) 2111.11 1126.78 45.87 C & E Loss (ft) 1.27 Cum SA (acres) 692.07 286.47 11.90 Plan: FwayM1 Colorado River Site 1 RS: 27494.84 Profile: PF 1 E.G. Elev (ft) 5400.76 Element Left OB Channel Right OB Vel Head (ft) 0.39 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5400.36 Reach Len. (ft) 1158.00 1239.23 1263.00 Crit W.S. (ft) Flow Area (sq ft) 4861.16 4177.35 18.47 E.G. Slope (ft/ft) 0.001737 Area (sq ft) 4861.16 4177.35 18.47 Q Total (cfs) 34900.00 Flow (cfs) 10420.06 24453.99 25.95 Top Width (ft) 1988.92 Top Width (ft) 1287.13 693.72 8.07 Vel Total (ft/s) 3.85 Avg. Vel. (ft/s) 2.14 5.85 1.41 Max Chl Dpth (ft) 6.45 Hydr. Depth (ft) 3.78 6.02 2.29 Conv. Total (cfs) 837333.6 Conv. (cfs) 250001.9 586709.1 622.6 Length Wtd. (ft) 1214.72 Wetted Per. (ft) 1289.08 694.24 9.23 Min Ch El (ft) 5394.00 Shear (lb/sq ft) 0.41 0.65 0.22 Alpha 1.71 Stream Power (lb/ft s) 0.88 3.82 0.30 Frctn Loss (ft) 2.95 Cum Volume (acre-ft) 2044.60 977.80 45.42 C & E Loss (ft) 0.03 Cum SA (acres) 674.46 261.42 11.70 Plan: FwayM1 Colorado River Site 1 RS: 26255.61 Profile: PF 1 E.G. Elev (ft) 5397.78 Element Left OB Channel Right OB Vel Head (ft) 0.71 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5397.07 Reach Len. (ft) 1050.00 1036.15 981.00 Crit W.S. (ft) Flow Area (sq ft) 4547.55 3056.94 E.G. Slope (ft/ft) 0.003637 Area (sq ft) 4547.55 3056.94 Q Total (cfs) 34900.00 Flow (cfs) 10650.84 24249.15 Top Width (ft) 2396.30 Top Width (ft) 1836.46 559.84 Vel Total (ft/s) 4.59 Avg. Vel. (ft/s) 2.34 7.93 Max Chl Dpth (ft) 6.54 Hydr. Depth (ft) 2.48 5.46 Conv. Total (cfs) 578683.9 Conv. (cfs) 176603.8 402080.1 Length Wtd. (ft) 1035.12 Wetted Per. (ft) 1837.77 560.58 Min Ch El (ft) 5390.53 Shear (lb/sq ft) 0.56 1.24 Alpha 2.16 Stream Power (lb/ft s) 1.32 9.82 Frctn Loss (ft) 4.10 Cum Volume (acre-ft) 1919.54 874.90 45.16 C & E Loss (ft) 0.05 Cum SA (acres) 632.94 243.59 11.58 Plan: FwayM1 Colorado River Site 1 RS: 25219.46 Profile: PF 1 E.G. Elev (ft) 5393.63 Element Left OB Channel Right OB Vel Head (ft) 0.54 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5393.09 Reach Len. (ft) 1167.00 1118.45 1053.00 Crit W.S. (ft) Flow Area (sq ft) 3947.71 2196.65 1915.77 E.G. Slope (ft/ft) 0.004325 Area (sq ft) 3947.71 2196.65 1915.77 Q Total (cfs) 34900.00 Flow (cfs) 11015.23 17142.44 6742.32 Top Width (ft) 2481.76 Top Width (ft) 1534.07 469.76 477.93 Vel Total (ft/s) 4.33 Avg. Vel. (ft/s) 2.79 7.80 3.52 Max Chl Dpth (ft) 7.09 Hydr. Depth (ft) 2.57 4.68 4.01 Conv. Total (cfs) 530694.1 Conv. (cfs) 167499.1 260670.3 102524.6 Length Wtd. (ft) 1129.40 Wetted Per. (ft) 1535.65 470.06 478.59 Min Ch El (ft) 5388.00 Shear (lb/sq ft) 0.69 1.26 1.08 Alpha 1.85 Stream Power (lb/ft s) 1.94 9.85 3.80 Frctn Loss (ft) 3.39 Cum Volume (acre-ft) 1817.15 812.41 23.58 C & E Loss (ft) 0.07 Cum SA (acres) 592.32 231.35 6.20 Plan: FwayM1 Colorado River Site 1 RS: 24101.01 Profile: PF 1 E.G. Elev (ft) 5390.18 Element Left OB Channel Right OB Vel Head (ft) 0.31 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5389.86 Reach Len. (ft) 1473.00 1412.79 1111.00 Crit W.S. (ft) Flow Area (sq ft) 6950.58 3812.73 3.74 E.G. Slope (ft/ft) 0.002201 Area (sq ft) 6950.58 3812.73 3.74 Q Total (cfs) 34900.00 Flow (cfs) 13817.05 21079.60 3.36 Top Width (ft) 3290.17 Top Width (ft) 2463.58 822.80 3.79 Vel Total (ft/s) 3.24 Avg. Vel. (ft/s) 1.99 5.53 0.90 Max Chl Dpth (ft) 6.11 Hydr. Depth (ft) 2.82 4.63 0.99 Conv. Total (cfs) 743889.4 Conv. (cfs) 294508.8 449309.1 71.5 Length Wtd. (ft) 1444.67 Wetted Per. (ft) 2464.64 824.45 4.37 Min Ch El (ft) 5383.97 Shear (lb/sq ft) 0.39 0.64 0.12 Alpha 1.91 Stream Power (lb/ft s) 0.77 3.51 0.11 Frctn Loss (ft) 4.42 Cum Volume (acre-ft) 1671.17 735.26 0.38 C & E Loss (ft) 0.00 Cum SA (acres) 538.77 214.75 0.38 Plan: FwayM1 Colorado River Site 1 RS: 22688.22 Profile: PF 1 E.G. Elev (ft) 5385.76 Element Left OB Channel Right OB Vel Head (ft) 0.33 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5385.43 Reach Len. (ft) 1763.00 1957.55 2135.00 Crit W.S. (ft) Flow Area (sq ft) 8428.58 1688.44 1.39 E.G. Slope (ft/ft) 0.004527 Area (sq ft) 8428.58 1688.44 1.39 Q Total (cfs) 34900.00 Flow (cfs) 23165.64 11732.96 1.40 Top Width (ft) 3654.56 Top Width (ft) 3208.84 444.13 1.59 Vel Total (ft/s) 3.45 Avg. Vel. (ft/s) 2.75 6.95 1.00 Max Chl Dpth (ft) 5.43 Hydr. Depth (ft) 2.63 3.80 0.88 Conv. Total (cfs) 518707.7 Conv. (cfs) 344303.6 174383.3 20.8 Length Wtd. (ft) 1819.93 Wetted Per. (ft) 3211.26 444.98 2.37 Min Ch El (ft) 5380.75 Shear (lb/sq ft) 0.74 1.07 0.17 Alpha 1.79 Stream Power (lb/ft s) 2.04 7.45 0.17 Frctn Loss (ft) 6.45 Cum Volume (acre-ft) 1411.14 646.05 0.32 C & E Loss (ft) 0.04 Cum SA (acres) 442.86 194.21 0.31 Plan: FwayM1 Colorado River Site 1 RS: 20730.67 Profile: PF 1 E.G. Elev (ft) 5379.28 Element Left OB Channel Right OB Vel Head (ft) 0.19 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5379.09 Reach Len. (ft) 1430.00 1332.44 1200.00 Crit W.S. (ft) Flow Area (sq ft) 9719.50 1675.51 1.65 E.G. Slope (ft/ft) 0.002846 Area (sq ft) 9719.50 1675.51 1.65 Q Total (cfs) 34900.00 Flow (cfs) 26213.27 8685.40 1.33 Top Width (ft) 3504.97 Top Width (ft) 3018.75 483.75 2.47 Vel Total (ft/s) 3.06 Avg. Vel. (ft/s) 2.70 5.18 0.80 Max Chl Dpth (ft) 7.09 Hydr. Depth (ft) 3.22 3.46 0.67 Conv. Total (cfs) 654172.5 Conv. (cfs) 491346.7 162800.9 24.9 Length Wtd. (ft) 1408.01 Wetted Per. (ft) 3020.93 483.92 2.75 Min Ch El (ft) 5374.88 Shear (lb/sq ft) 0.57 0.62 0.11 Alpha 1.30 Stream Power (lb/ft s) 1.54 3.19 0.09 Frctn Loss (ft) 3.62 Cum Volume (acre-ft) 1043.89 570.47 0.24 C & E Loss (ft) 0.02 Cum SA (acres) 316.84 173.36 0.21 Plan: FwayM1 Colorado River Site 1 RS: 19398.23 Profile: PF 1 E.G. Elev (ft) 5375.64 Element Left OB Channel Right OB Vel Head (ft) 0.12 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5375.52 Reach Len. (ft) 1603.00 1689.97 1773.00 Crit W.S. (ft) Flow Area (sq ft) 11872.55 1707.28 1.89 E.G. Slope (ft/ft) 0.002332 Area (sq ft) 11872.55 1707.28 1.89 Q Total (cfs) 34900.00 Flow (cfs) 27855.12 7043.32 1.56 Top Width (ft) 4022.92 Top Width (ft) 3423.79 597.33 1.80 Vel Total (ft/s) 2.57 Avg. Vel. (ft/s) 2.35 4.13 0.83 Max Chl Dpth (ft) 7.52 Hydr. Depth (ft) 3.47 2.86 1.05 Conv. Total (cfs) 722726.4 Conv. (cfs) 576837.4 145856.6 32.3 Length Wtd. (ft) 1627.56 Wetted Per. (ft) 3428.88 598.09 2.61 Min Ch El (ft) 5372.00 Shear (lb/sq ft) 0.50 0.42 0.11 Alpha 1.19 Stream Power (lb/ft s) 1.18 1.71 0.09 Frctn Loss (ft) 3.64 Cum Volume (acre-ft) 689.47 518.73 0.19 C & E Loss (ft) 0.01 Cum SA (acres) 211.09 156.82 0.15 Plan: FwayM1 Colorado River Site 1 RS: 17708.26 Profile: PF 1 E.G. Elev (ft) 5372.00 Element Left OB Channel Right OB Vel Head (ft) 0.20 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5371.79 Reach Len. (ft) 2036.00 1873.91 2008.00 Crit W.S. (ft) Flow Area (sq ft) 8368.25 2601.75 2.56 E.G. Slope (ft/ft) 0.002145 Area (sq ft) 8368.25 2601.75 2.56 Q Total (cfs) 34900.00 Flow (cfs) 22240.22 12657.77 2.01 Top Width (ft) 2550.16 Top Width (ft) 1880.86 667.70 1.60 Vel Total (ft/s) 3.18 Avg. Vel. (ft/s) 2.66 4.87 0.79 Max Chl Dpth (ft) 7.76 Hydr. Depth (ft) 4.45 3.90 1.60 Conv. Total (cfs) 753635.3 Conv. (cfs) 480258.2 273333.6 43.4 Length Wtd. (ft) 1933.26 Wetted Per. (ft) 1882.44 668.37 3.57 Min Ch El (ft) 5366.00 Shear (lb/sq ft) 0.60 0.52 0.10 Alpha 1.29 Stream Power (lb/ft s) 1.58 2.54 0.08 Frctn Loss (ft) 5.87 Cum Volume (acre-ft) 317.04 435.14 0.10 C & E Loss (ft) 0.03 Cum SA (acres) 113.49 132.29 0.08 Plan: FwayM1 Colorado River Site 1 RS: 15834.35 Profile: PF 1 E.G. Elev (ft) 5366.09 Element Left OB Channel Right OB Vel Head (ft) 0.50 Wt. n-Val. 0.070 0.035 W.S. Elev (ft) 5365.59 Reach Len. (ft) 2339.00 1918.66 1085.00 Crit W.S. (ft) Flow Area (sq ft) 1638.93 5324.94 E.G. Slope (ft/ft) 0.004620 Area (sq ft) 1638.93 5324.94 Q Total (cfs) 34900.00 Flow (cfs) 3317.35 31582.65 Top Width (ft) 2814.29 Top Width (ft) 1009.03 1805.26 Vel Total (ft/s) 5.01 Avg. Vel. (ft/s) 2.02 5.93 Max Chl Dpth (ft) 3.68 Hydr. Depth (ft) 1.62 2.95 Conv. Total (cfs) 513440.2 Conv. (cfs) 48804.0 464636.2 Length Wtd. (ft) 1953.01 Wetted Per. (ft) 1009.59 1807.21 Min Ch El (ft) 5361.91 Shear (lb/sq ft) 0.47 0.85 Alpha 1.28 Stream Power (lb/ft s) 0.95 5.04 Frctn Loss (ft) 6.10 Cum Volume (acre-ft) 83.18 264.64 0.04 C & E Loss (ft) 0.05 Cum SA (acres) 45.95 79.09 0.05 Plan: FwayM1 Colorado River Site 1 RS: 13915.69 Profile: PF 1 E.G. Elev (ft) 5359.94 Element Left OB Channel Right OB Vel Head (ft) 0.34 Wt. n-Val. 0.070 0.035 0.070 W.S. Elev (ft) 5359.60 Reach Len. (ft) Crit W.S. (ft) 5358.10 Flow Area (sq ft) 1459.11 6691.67 3.55 E.G. Slope (ft/ft) 0.002251 Area (sq ft) 1459.11 6691.67 3.55 Q Total (cfs) 34900.00 Flow (cfs) 2392.54 32504.24 3.22 Top Width (ft) 2492.14 Top Width (ft) 702.41 1786.08 3.65 Vel Total (ft/s) 4.28 Avg. Vel. (ft/s) 1.64 4.86 0.91 Max Chl Dpth (ft) 5.91 Hydr. Depth (ft) 2.08 3.75 0.97 Conv. Total (cfs) 735527.1 Conv. (cfs) 50423.4 685035.7 67.9 Length Wtd. (ft) Wetted Per. (ft) 702.45 1787.14 4.16 Min Ch El (ft) 5353.69 Shear (lb/sq ft) 0.29 0.53 0.12 Alpha 1.21 Stream Power (lb/ft s) 0.48 2.56 0.11 Frctn Loss (ft) Cum Volume (acre-ft) C & E Loss (ft) Cum SA (acres) 01000200030004000535053555360536553705375538053855390Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1Crit PF 2 - FwayM1Crit PF 1 - FwayM1Crit PF 1 - Existing2GroundBank StaEncroachment.07.035.07 05001000150020002500300035005404540654085410541254145416541854205422Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - FwayM1EG PF 1 - Existing2WS PF 1 - FwayM1WS PF 1 - Existing2GroundBank StaEncroachment.07.035.07 0200400600800100012001400540054025404540654085410541254145416Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 1 - Existing2EG PF 1 - FwayM1EG PF 2 - FwayM1WS PF 1 - FwayM1WS PF 1 - Existing2WS PF 2 - FwayM1Crit PF 1 - Existing2Crit PF 1 - FwayM1Crit PF 2 - FwayM1GroundBank Sta.07.035.07 020040060080010001200140054005405541054155420Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 I-70 Bridge over Colorado River (ft) (ft)LegendEG PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 2 - FwayM1WS PF 1 - FwayM1WS PF 1 - Existing2Crit PF 1 - Existing2Crit PF 1 - FwayM1Crit PF 2 - FwayM1GroundBank Sta.07.035.07 02004006008001000120014005400540254045406540854105412541454165418Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 I-70 Bridge over Colorado River (ft) (ft)LegendEG PF 1 - Existing2EG PF 1 - FwayM1EG PF 2 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1WS PF 2 - FwayM1Crit PF 1 - FwayM1Crit PF 2 - FwayM1Crit PF 1 - Existing2GroundBank StaEncroachment.07.035.07 020040060080010001200140054005402540454065408541054125414Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 1 - Existing2EG PF 1 - FwayM1EG PF 2 - FwayM1WS PF 1 - FwayM1Crit PF 1 - FwayM1WS PF 2 - FwayM1Crit PF 2 - FwayM1Crit PF 1 - Existing2WS PF 1 - Existing2GroundBank Sta.07.035.07 050010001500200025005390540054105420543054405450Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 0500100015002000250030003500539054005410542054305440Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 2 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 01000200030004000538053905400541054205430Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 2 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 010002000300040005000538053905400541054205430Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - FwayM1EG PF 1 - Existing2WS PF 1 - FwayM1WS PF 1 - Existing2GroundBank StaEncroachment.07.035.07 0100020003000400050006000535053605370538053905400541054205430Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - FwayM1EG PF 1 - Existing2WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 0100020003000400050006000534053605380540054205440Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 0100020003000400050006000700053605370538053905400541054205430Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 01000200030004000500060007000535053605370538053905400541054205430Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1WS PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1GroundBank StaEncroachment.07.035.07 010002000300040005000536053655370537553805385Colorado River Plan: 1) Existing2 5/14/2020 2) FwayM1 9/14/2020 (ft) (ft)LegendEG PF 2 - FwayM1EG PF 1 - Existing2EG PF 1 - FwayM1WS PF 1 - Existing2WS PF 1 - FwayM1WS PF 2 - FwayM1GroundBank StaEncroachment.07.035.07 Attachment 3 www.sgm-inc.com Land Title Guarantee Company Customer Distribution PREVENT FRAUD - Please remember to call a member of our closing team when initiating a wire transfer or providing wiring instructions. Order Number:ABS63013676.1 Date: 09/08/2020 Property Address:MALONE RANCH, SILT, CO 81650 PLEASE CONTACT YOUR CLOSER OR CLOSER'S ASSISTANT FOR WIRE TRANSFER INSTRUCTIONS For Closing Assistance For Title Assistance Scott Cieslewicz 5975 GREENWOOD PLAZA BLVD GREENWOOD VILLAGE, CO 80111 (303) 850-4189 (Work) scieslewicz@ltgc.com Seller/Owner SCOTT CONTRACTING, INC. Attention: CHRISTOPHER HURLEY (720) 490-7407 (Cell) (720) 889-4402 (Work) churley@scottcontracting.com> Delivered via: Electronic Mail Land Title Guarantee Company Estimate of Title Fees Order Number:ABS63013676.1 Date: 09/08/2020 Property Address:MALONE RANCH, SILT, CO 81650 Parties:A BUYER TO BE DETERMINED SCOTT CONTRACTING, INC. A COLORADO CORPORATION Visit Land Title's Website at www.ltgc.com for directions to any of our offices. Estimate of Title insurance Fees "ALTA" Owner's Policy 06-17-06 TBD Total TBD If Land Title Guarantee Company will be closing this transaction, the fees listed above will be collected at closing. Thank you for your order! Note: The documents linked in this commitment should be reviewed carefully. These documents, such as covenants conditions and restrictions, may affect the title, ownership and use of the property. You may wish to engage legal assistance in order to fully understand and be aware of the implications of the effect of these documents on your property. Chain of Title Documents: Garfield county recorded 06/03/2009 under reception no. 769092 Garfield county recorded 09/13/2019 under reception no. 925393 Property Address: MALONE RANCH, SILT, CO 81650 1.Effective Date: 08/21/2020 at 5:00 P.M. 2.Policy to be Issued and Proposed Insured: "ALTA" Owner's Policy 06-17-06 Proposed Insured: A BUYER TO BE DETERMINED TBD 3.The estate or interest in the land described or referred to in this Commitment and covered herein is: A FEE SIMPLE 4.Title to the estate or interest covered herein is at the effective date hereof vested in: SCOTT CONTRACTING, INC. A COLORADO CORPORATION 5.The Land referred to in this Commitment is described as follows: TOWNSHIP 6 SOUTH, RANGE 92 WEST OF THE 6TH P.M., SECTION 8: S1/2 SW 1/4 SECTION 17: NE 1/4 NW 1/4 AND NW 1/4 NW 1/4 LESS AND EXCEPTING THE FOLLOWING TRACTS OF LAND PREVIOUSLY CONVEYED AND RECORDED: 1. A TRACT OF LAND LOCATED IN THE SW 1/4 SW 1/4 SECTION 8, AND THE NW1/4 NW 1/4 SECTION 17, CONVEYED BY GEORGE YULE BY WARRANTY DEED RECORDED APRIL 17, 1893 IN BOOK 32 AT PAGE 425. 2. A TRACT OF LAND LYING IN THE SE CORNER OF THE NE 1/4 NW 1/4 OF SECTION 17 AS GRANTED TO SCHOOL DISTRICT 27 OF GARFIELD COUNTY BY WARRANTY DEED DATED OCTOBER 10, 1891, RECORDED OCTOBER 12, 1891 IN BOOK 25 AT PAGE 188. 3. A TRACT OF LAND LYING IN THE SE 1/4 SW 1/4 SECTION 8, AND N 1/2 NW 1/4 SECTION 17 COMPRISING INTERSTATE HIGHWAY 70 R.O.W., INCLUDING: THAT PART OF THE N 1/2 NW 1/4 SECTION 17 CONVEYED TO THE BOARD OF COUNTY COMMISSIONERS OF THE COUNTY OF GARFIELD, STATE OF COLORADO AND STATE DEPARTMENT OF HIGHWAYS, DIVISION OF HIGHWAYS, STATE OF COLORADO BY COURT ORDER RECORDED FEBRUARY 24, 1977 IN BOOK 493 AT PAGE 768. 4. THAT PORTION OF THE NE1/4NW1/4 AND NW1/4NW1/4 OF SECTION 17, TOWNSHIP 6 SOUTH, RANGE 92 WEST, SITUATE SOUTHERLY OF THE INTERSTATE HIGHWAY 70 RIGHT OF WAY, AS CONVEYED TO JACQUE COUEY BURRIS BY SPECIAL WARRANTY DEED RECORDED OCTOBER 4, 1991 IN BOOK 814 AT PAGE 812. COUNTY OF GARFIELD, STATE OF COLORADO. ALTA COMMITMENT Old Republic National Title Insurance Company Schedule A Order Number:ABS63013676.1 Copyright 2006-2020 American Land Title Association. All rights reserved. The use of this Form is restricted to ALTA licensees and ALTA members in good standing as of the date of use. All other uses are prohibited. Reprinted under license from the American Land Title Association. ALTA COMMITMENT Old Republic National Title Insurance Company Schedule A Order Number:ABS63013676.1 ALTA COMMITMENT Old Republic National Title Insurance Company Schedule B, Part I (Requirements) Order Number: ABS63013676.1 All of the following Requirements must be met: This proposed Insured must notify the Company in writing of the name of any party not referred to in this Commitment who will obtain an interest in the Land or who will make a loan on the Land. The Company may then make additional Requirements or Exceptions. Pay the agreed amount for the estate or interest to be insured. Pay the premiums, fees, and charges for the Policy to the Company. Documents satisfactory to the Company that convey the Title or create the Mortgage to be insured, or both, must be properly authorized, executed, delivered, and recorded in the Public Records. THIS COMMITMENT IS FOR INFORMATION ONLY, AND NO POLICY WILL BE ISSUED PURSUANT HERETO. This commitment does not republish any covenants, condition, restriction, or limitation contained in any document referred to in this commitment to the extent that the specific covenant, conditions, restriction, or limitation violates state or federal law based on race, color, religion, sex, sexual orientation, gender identity, handicap, familial status, or national origin. 1.Any facts, rights, interests, or claims thereof, not shown by the Public Records but that could be ascertained by an inspection of the Land or that may be asserted by persons in possession of the Land. 2.Easements, liens or encumbrances, or claims thereof, not shown by the Public Records. 3.Any encroachment, encumbrance, violation, variation, or adverse circumstance affecting the Title that would be disclosed by an accurate and complete land survey of the Land and not shown by the Public Records. 4.Any lien, or right to a lien, for services, labor or material heretofore or hereafter furnished, imposed by law and not shown by the Public Records. 5.Defects, liens, encumbrances, adverse claims or other matters, if any, created, first appearing in the public records or attaching subsequent to the effective date hereof but prior to the date of the proposed insured acquires of record for value the estate or interest or mortgage thereon covered by this Commitment. 6.(a) Taxes or assessments that are not shown as existing liens by the records of any taxing authority that levies taxes or assessments on real property or by the Public Records; (b) proceedings by a public agency that may result in taxes or assessments, or notices of such proceedings, whether or not shown by the records of such agency or by the Public Records. 7.(a) Unpatented mining claims; (b) reservations or exceptions in patents or in Acts authorizing the issuance thereof; (c) water rights, claims or title to water. 8.EXISTING LEASES AND TENANCIES, IF ANY. NOTE: UPON RECEIPT OF THE SIGNED FINAL SELLER AFFIDAVIT STATING HERE ARE NO EXISTING LEASES OR TENANCIES THE ABOVE ITEM WILL BE REMOVED, 9.ANY AND ALL RIGHTS OF A DITCH COMPANY RELATING TO THE LAST CHANCE DITCH TRAVERSING SUBJECT PROPERTY, INCLUDING BUT NOT LIMITED TO DITCH MAINTENANCE AND ACCESS RIGHTS TO LANDS ADJOINING THE DITCH OR CANAL. 10.NOTWITHSTANDING THE INSURING CLAUSES OF THE POLICY, THE COMPANY DOES NOT INSURE AGAINST LOSS OR DAMAGE BY REASON OF A LACK OF A RIGHT OF PHYSICAL ACCESS TO AND FROM THE LAND. 11.RIGHT OF THE PROPRIETOR OF A VEIN OR LODE TO EXTRACT AND REMOVE HIS ORE THEREFROM, SHOULD THE SAME BE FOUND TO PENETRATE OR INTERSECT THE PREMISES HEREBY GRANTED, AND A RIGHT OF WAY FOR DITCHES OR CANALS CONSTRUCTED BY THE AUTHORITY OF THE UNITED STATES, AS RESERVED IN UNITED STATES PATENT RECORDED MARCH 05, 1906 IN BOOK 56 AT PAGE 537. ALTA COMMITMENT Old Republic National Title Insurance Company Schedule B, Part II (Exceptions) Order Number: ABS63013676.1 12.RESERVATION OF ONE-HALF INTEREST IN ALL OIL, GAS AND OTHER MINERALS AS EVIDENCED IN INSTRUMENT RECORDED MARCH 27, 1972 IN BOOK 428 AT PAGE 459, AND ANY AND ALL ASSIGNMENTS THEREOF OR INTERESTS THEREIN. 13.ALL OIL, GAS, HYDROCARBONS AND OTHER MINERALS, TOGETHER WITH SO MUCH OF THE SURFACE AS MAY BE NECESSARY FOR THE CONVENIENT MINING OR EXTRACTION OF SAME, AND TOGETHER, FURTHER, THE RIGHT OF INGRESS AND EGRESS FOR THE PURPOSES OF PROSPECTING FOR, DEVELOPING AND PRODUCING SAME, AS RESERVED IN INSTRUMENTS RECORDED FEBRUARY 13, 1973 IN BOOK 440 AT PAGE 469, AND ANY AND ALL ASSIGNMENTS THEREOF OR INTERESTS THEREIN. 14.NO RIGHT OR RIGHTS OF ACCESS TO AND FROM THE HIGHWAY AS EVIDENCED IN RULE AND ORDER RECORDED FEBRUARY 24, 1977 IN BOOK 493 AT PAGE 768. 15.OIL AND GAS LEASE RECORDED NOVEMBER 02, 1982, IN BOOK 612 AT PAGE 973, AND ANY AND ALL ASSIGNMENTS THEREOF OR INTERESTS THEREIN. 16.RESERVATION OF ALL OIL SHALE, KEROGEN, SHALE OIL, COAL, OIL, GAS, FISSIONABLE MATERIAL AN ALL OTHER MINERALS OF ANY KIND OR NATURE AS EVIDENCED BY SPECIAL WARRANTY DEED RECORDED NOVEMBER 03, 1989 IN BOOK 766 AT PAGE 317, AND ANY AND ALL ASSIGNMENTS THEREOF OR INTERESTS THEREIN. 17.TERMS, CONDITIONS, PROVISIONS, BURDENS AND OBLIGATIONS AS SET FORTH IN WATER WELL SHARING AGREEMENT RECORDED JUNE 05, 2009 UNDER RECEPTION NO. 769089. 18.ANY INCREASE OR DECREASE IN THE AREA OF THE LAND AND ANY ADVERSE CLAIM TO ANY PORTION OF THE LAND WHICH HAS BEEN CREATED BY OR CAUSED BY ACCRETION OR RELICTION, WHETHER NATURAL OR ARTIFICIAL; AND THE EFFECT OF THE GAIN OR LOSS OF AREA BY ACCRETION OR RELICTION UPON THE MARKETABILITY OF THE TITLE OF THE LAND. 19.ANY FACTS, RIGHTS, INTERESTS OR CLAIMS WHICH MAY EXIST OR ARISE BY REASON OF THE FOLLOWING FACTS SHOWN ON ALTA/NSPS LAND TITLE SURVEY CERTIFIED AUGUST 08, 2019 PREPARED BY SHAWN BINION, P.L.S. #38200, ON BEHALF OF SGM INC., JOB #2019-341.001 SAID DOCUMENT STORED AS OUR IMAGE 18207166 FENCE LINES DO NOT COINCIDE WITH THE PROPERTY BOUNDARIES ALTA COMMITMENT Old Republic National Title Insurance Company Schedule B, Part II (Exceptions) Order Number: ABS63013676.1 LAND TITLE GUARANTEE COMPANY DISCLOSURE STATEMENTS Note: Pursuant to CRS 10-11-122, notice is hereby given that: Note: Effective September 1, 1997, CRS 30-10-406 requires that all documents received for recording or filing in the clerk and recorder's office shall contain a top margin of at least one inch and a left, right and bottom margin of at least one half of an inch. The clerk and recorder may refuse to record or file any document that does not conform, except that, the requirement for the top margin shall not apply to documents using forms on which space is provided for recording or filing information at the top margin of the document. Note: Colorado Division of Insurance Regulations 8-1-2 requires that "Every title entity shall be responsible for all matters which appear of record prior to the time of recording whenever the title entity conducts the closing and is responsible for recording or filing of legal documents resulting from the transaction which was closed". Provided that Land Title Guarantee Company conducts the closing of the insured transaction and is responsible for recording the legal documents from the transaction, exception number 5 will not appear on the Owner's Title Policy and the Lenders Policy when issued. Note: Affirmative mechanic's lien protection for the Owner may be available (typically by deletion of Exception no. 4 of Schedule B, Section 2 of the Commitment from the Owner's Policy to be issued) upon compliance with the following conditions: No coverage will be given under any circumstances for labor or material for which the insured has contracted for or agreed to pay. The Subject real property may be located in a special taxing district.(A) A certificate of taxes due listing each taxing jurisdiction will be obtained from the county treasurer of the county in which the real property is located or that county treasurer's authorized agent unless the proposed insured provides written instructions to the contrary. (for an Owner's Policy of Title Insurance pertaining to a sale of residential real property). (B) The information regarding special districts and the boundaries of such districts may be obtained from the Board of County Commissioners, the County Clerk and Recorder, or the County Assessor. (C) The land described in Schedule A of this commitment must be a single family residence which includes a condominium or townhouse unit. (A) No labor or materials have been furnished by mechanics or material-men for purposes of construction on the land described in Schedule A of this Commitment within the past 6 months. (B) The Company must receive an appropriate affidavit indemnifying the Company against un-filed mechanic's and material-men's liens. (C) The Company must receive payment of the appropriate premium.(D) If there has been construction, improvements or major repairs undertaken on the property to be purchased within six months prior to the Date of Commitment, the requirements to obtain coverage for unrecorded liens will include: disclosure of certain construction information; financial information as to the seller, the builder and or the contractor; payment of the appropriate premium fully executed Indemnity Agreements satisfactory to the company, and, any additional requirements as may be necessary after an examination of the aforesaid information by the Company. (E) Note: Pursuant to CRS 10-11-123, notice is hereby given: This notice applies to owner's policy commitments disclosing that a mineral estate has been severed from the surface estate, in Schedule B-2. Note: Pursuant to CRS 10-1-128(6)(a), It is unlawful to knowingly provide false, incomplete, or misleading facts or information to an insurance company for the purpose of defrauding or attempting to defraud the company. Penalties may include imprisonment, fines, denial of insurance, and civil damages. Any insurance company or agent of an insurance company who knowingly provides false, incomplete, or misleading facts or information to a policyholder or claimant for the purpose of defrauding or attempting to defraud the policyholder or claimant with regard to a settlement or award payable from insurance proceeds shall be reported to the Colorado Division of Insurance within the Department of Regulatory Agencies. Note: Pursuant to Colorado Division of Insurance Regulations 8-1-3, notice is hereby given of the availability of a closing protection letter for the lender, purchaser, lessee or seller in connection with this transaction. That there is recorded evidence that a mineral estate has been severed, leased, or otherwise conveyed from the surface estate and that there is substantial likelihood that a third party holds some or all interest in oil, gas, other minerals, or geothermal energy in the property; and (A) That such mineral estate may include the right to enter and use the property without the surface owner's permission. (B) JOINT NOTICE OF PRIVACY POLICY OF LAND TITLE GUARANTEE COMPANY, LAND TITLE GUARANTEE COMPANY OF SUMMIT COUNTY LAND TITLE INSURANCE CORPORATION AND OLD REPUBLIC NATIONAL TITLE INSURANCE COMPANY This Statement is provided to you as a customer of Land Title Guarantee Company as agent for Land Title Insurance Corporation and Old Republic National Title Insurance Company. We want you to know that we recognize and respect your privacy expectations and the requirements of federal and state privacy laws. Information security is one of our highest priorities. We recognize that maintaining your trust and confidence is the bedrock of our business. We maintain and regularly review internal and external safeguards against unauthorized access to your non-public personal information ("Personal Information"). In the course of our business, we may collect Personal Information about you from: applications or other forms we receive from you, including communications sent through TMX, our web-based transaction management system; your transactions with, or from the services being performed by us, our affiliates, or others; a consumer reporting agency, if such information is provided to us in connection with your transaction; and The public records maintained by governmental entities that we obtain either directly from those entities, or from our affiliates and non-affiliates. Our policies regarding the protection of the confidentiality and security of your Personal Information are as follows: We restrict access to all Personal Information about you to those employees who need to know that information in order to provide products and services to you. We may share your Personal Information with affiliated contractors or service providers who provide services in the course of our business, but only to the extent necessary for these providers to perform their services and to provide these services to you as may be required by your transaction. We maintain physical, electronic and procedural safeguards that comply with federal standards to protect your Personal Information from unauthorized access or intrusion. Employees who violate our strict policies and procedures regarding privacy are subject to disciplinary action. We regularly assess security standards and procedures to protect against unauthorized access to Personal Information. WE DO NOT DISCLOSE ANY PERSONAL INFORMATION ABOUT YOU WITH ANYONE FOR ANY PURPOSE THAT IS NOT STATED ABOVE OR PERMITTED BY LAW. Consistent with applicable privacy laws, there are some situations in which Personal Information may be disclosed. We may disclose your Personal Information when you direct or give us permission; when we are required by law to do so, for example, if we are served a subpoena; or when we suspect fraudulent or criminal activities. We also may disclose your Personal Information when otherwise permitted by applicable privacy laws such as, for example, when disclosure is needed to enforce our rights arising out of any agreement, transaction or relationship with you. Our policy regarding dispute resolution is as follows: Any controversy or claim arising out of or relating to our privacy policy, or the breach thereof, shall be settled by arbitration in accordance with the rules of the American Arbitration Association, and judgment upon the award rendered by the arbitrator(s) may be entered in any court having jurisdiction thereof. Commitment For Title Insurance Issued by Old Republic National Title Insurance Corporation NOTICE IMPORTANT—READ CAREFULLY: THIS COMMITMENT IS AN OFFER TO ISSUE ONE OR MORE TITLE INSURANCE POLICIES. ALL CLAIMS OR REMEDIES SOUGHT AGAINST THE COMPANY INVOLVING THE CONTENT OF THIS COMMITMENT OR THE POLICY MUST BE BASED SOLELY IN CONTRACT. THIS COMMITMENT IS NOT AN ABSTRACT OF TITLE, REPORT OF THE CONDITION OF TITLE, LEGAL OPINION, OPINION OF TITLE, OR OTHER REPRESENTATION OF THE STATUS OF TITLE. THE PROCEDURES USED BY THE COMPANY TO DETERMINE INSURABILITY OF THE TITLE, INCLUDING ANY SEARCH AND EXAMINATION, ARE PROPRIETARY TO THE COMPANY, WERE PERFORMED SOLELY FOR THE BENEFIT OF THE COMPANY, AND CREATE NO EXTRACONTRACTUAL LIABILITY TO ANY PERSON, INCLUDING A PROPOSED INSURED. THE COMPANY’S OBLIGATION UNDER THIS COMMITMENT IS TO ISSUE A POLICY TO A PROPOSED INSURED IDENTIFIED IN SCHEDULE A IN ACCORDANCE WITH THE TERMS AND PROVISIONS OF THIS COMMITMENT. THE COMPANY HAS NO LIABILITY OR OBLIGATION INVOLVING THE CONTENT OF THIS COMMITMENT TO ANY OTHER PERSON. . COMMITMENT TO ISSUE POLICY Subject to the Notice; Schedule B, Part I—Requirements; Schedule B, Part II—Exceptions; and the Commitment Conditions, Old Republic National Title Insurance Company, a Minnesota corporation (the “Company”), commits to issue the Policy according to the terms and provisions of this Commitment. This Commitment is effective as of the Commitment Date shown in Schedule A for each Policy described in Schedule A, only when the Company has entered in Schedule A both the specified dollar amount as the Proposed Policy Amount and the name of the Proposed Insured. If all of the Schedule B, Part I—Requirements have not been met within 6 months after the Commitment Date, this Commitment terminates and the Company’s liability and obligation end. COMMITMENT CONDITIONS 1. DEFINITIONS 2. If all of the Schedule B, Part I—Requirements have not been met within the time period specified in the Commitment to Issue Policy, Commitment terminates and the Company’s liability and obligation end. 3. The Company’s liability and obligation is limited by and this Commitment is not valid without: 4. COMPANY’S RIGHT TO AMEND The Company may amend this Commitment at any time. If the Company amends this Commitment to add a defect, lien, encumbrance, adverse claim, or other matter recorded in the Public Records prior to the Commitment Date, any liability of the Company is limited by Commitment Condition 5. The Company shall not be liable for any other amendment to this Commitment. 5. LIMITATIONS OF LIABILITY i. comply with the Schedule B, Part I—Requirements; ii. eliminate, with the Company’s written consent, any Schedule B, Part II—Exceptions; or iii. acquire the Title or create the Mortgage covered by this Commitment. “Knowledge” or “Known”: Actual or imputed knowledge, but not constructive notice imparted by the Public Records.(a) “Land”: The land described in Schedule A and affixed improvements that by law constitute real property. The term “Land” does not include any property beyond the lines of the area described in Schedule A, nor any right, title, interest, estate, or easement in abutting streets, roads, avenues, alleys, lanes, ways, or waterways, but this does not modify or limit the extent that a right of access to and from the Land is to be insured by the Policy. (b) “Mortgage”: A mortgage, deed of trust, or other security instrument, including one evidenced by electronic means authorized by law.(c) “Policy”: Each contract of title insurance, in a form adopted by the American Land Title Association, issued or to be issued by the Company pursuant to this Commitment. (d) “Proposed Insured”: Each person identified in Schedule A as the Proposed Insured of each Policy to be issued pursuant to this Commitment.(e) “Proposed Policy Amount”: Each dollar amount specified in Schedule A as the Proposed Policy Amount of each Policy to be issued pursuant to this Commitment. (f) “Public Records”: Records established under state statutes at the Commitment Date for the purpose of imparting constructive notice of matters relating to real property to purchasers for value and without Knowledge. (g) “Title”: The estate or interest described in Schedule A.(h) the Notice;(a) the Commitment to Issue Policy;(b) the Commitment Conditions;(c) Schedule A;(d) Schedule B, Part I—Requirements; and(e) Schedule B, Part II—Exceptions; and(f) a counter-signature by the Company or its issuing agent that may be in electronic form.(g) The Company’s liability under Commitment Condition 4 is limited to the Proposed Insured’s actual expense incurred in the interval between the Company’s delivery to the Proposed Insured of the Commitment and the delivery of the amended Commitment, resulting from the Proposed Insured’s good faith reliance to: (a) The Company shall not be liable under Commitment Condition 5(a) if the Proposed Insured requested the amendment or had Knowledge of the matter and did not notify the Company about it in writing. (b) The Company will only have liability under Commitment Condition 4 if the Proposed Insured would not have incurred the expense had the Commitment included the added matter when the Commitment was first delivered to the Proposed Insured. (c) The Company’s liability shall not exceed the lesser of the Proposed Insured’s actual expense incurred in good faith and described in Commitment Conditions 5(a)(i) through 5(a)(iii) or the Proposed Policy Amount. (d) The Company shall not be liable for the content of the Transaction Identification Data, if any.(e) 6. LIABILITY OF THE COMPANY MUST BE BASED ON THIS COMMITMENT 7. IF THIS COMMITMENT HAS BEEN ISSUED BY AN ISSUING AGENT The issuing agent is the Company’s agent only for the limited purpose of issuing title insurance commitments and policies. The issuing agent is not the Company’s agent for the purpose of providing closing or settlement services. 8. PRO-FORMA POLICY The Company may provide, at the request of a Proposed Insured, a pro-forma policy illustrating the coverage that the Company may provide. A pro-forma policy neither reflects the status of Title at the time that the pro-forma policy is delivered to a Proposed Insured, nor is it a commitment to insure. 9. ARBITRATION The Policy contains an arbitration clause. All arbitrable matters when the Proposed Policy Amount is $2,000,000 or less shall be arbitrated at the option of either the Company or the Proposed Insured as the exclusive remedy of the parties. A Proposed Insured may review a copy of the arbitration rules at http://www.alta.org/arbitration. IN WITNESS WHEREOF, Land Title Insurance Corporation has caused its corporate name and seal to be affixed by its duly authorized officers on the date shown in Schedule A to be valid when countersigned by a validating officer or other authorized signatory. Issued by: Land Title Guarantee Company 3033 East First Avenue Suite 600 Denver, Colorado 80206 303-321-1880 Senior Vice President This page is only a part of a 2016 ALTA® Commitment for Title Insurance issued by Land Title Insurance Corporation. This Commitment is not valid without the Notice; the Commitment to Issue Policy; the Commitment Conditions; Schedule A; Schedule B, Part I—Requirements; and Schedule B, Part II—Exceptions; and a counter-signature by the Company or its issuing agent that may be in electronic form. Copyright 2006-2016 American Land Title Association. All rights reserved. The use of this Form (or any derivative thereof) is restricted to ALTA licensees and ALTA members in good standing as of the date of use. All other uses are prohibited. Reprinted under license from the American Land Title Association. In no event shall the Company be obligated to issue the Policy referred to in this Commitment unless all of the Schedule B, Part I—Requirements have been met to the satisfaction of the Company. (f) In any event, the Company’s liability is limited by the terms and provisions of the Policy.(g) Only a Proposed Insured identified in Schedule A, and no other person, may make a claim under this Commitment.(a) Any claim must be based in contract and must be restricted solely to the terms and provisions of this Commitment.(b) Until the Policy is issued, this Commitment, as last revised, is the exclusive and entire agreement between the parties with respect to the subject matter of this Commitment and supersedes all prior commitment negotiations, representations, and proposals of any kind, whether written or oral, express or implied, relating to the subject matter of this Commitment. (c) The deletion or modification of any Schedule B, Part II—Exception does not constitute an agreement or obligation to provide coverage beyond the terms and provisions of this Commitment or the Policy. (d) Any amendment or endorsement to this Commitment must be in writing and authenticated by a person authorized by the Company.(e) When the Policy is issued, all liability and obligation under this Commitment will end and the Company’s only liability will be under the Policy.(f) Attachment 4 www.sgm-inc.com Rifle Pit #1 - Neighboring Parcel Mailing List Parcel Number Physical Address Owner(s)Account Number Mailing Address 217907100292 Not available SILT ISLAND PARK LLC R024363 2311 MEADOWLARK LANE GLENWOOD SPRINGS, CO 81601 217908100527 Not available SILT SHIELEROSA LLLP R230963 1411 COUNTY ROAD 316 SILT, CO 81652 217908200101 6073 346 COUNTY RD, SILT COLORADO RIVER RANCH, LLC R023384 10 MUSTANG DRIVE NEW CASTLE, CO 81647 217908300102 Not available SILT REX ROBINSON RANCH LLC & SWANSON COLORADO TRUST & ILGEN, CARROL JEANNE & ROSA, LINDA JANE & ROBINSON, JAMES DEAN R023138 5473 N CRESCENT RIDGE DRIVE TUCSON, AZ 85718 217908300103 Not available SILT SCOTT CONTRACTING INC R023405 9200 MINERAL AVENUE #400 CENTENNIAL, CO 80112 ROW Not available null Attachment 5 www.sgm-inc.com Attachment 6 www.sgm-inc.com Title:Piezometer StudyExhibitRevision# Rifle Pit #1 Rifle, COJob No.Drawn by:Date:File:PE:QC:2019-341.002RPF03.24.2021RPFRiflePit-Piezo-Exhibit--118 West Sixth Street, Suite 200Glenwood Springs, CO 81601 970.945.1004 www.sgm-inc.com Date By: Not For ConstructionProject Milestone:Graphic ScaleIn Feet: 1" = 200'0100200400 August 5, 2019 Chris Hurley, Corporate Counsel Scott Contracting, Inc 9200 E. Mineral Avenue, Suite 400 Centennial, Colorado 80112 RE: Summary of Environmental (Wetland) Findings for the Rifle Gravel Pit #1 Property Dear Chris, A summary of the Environmental (Wetland) Findings for the Rifle Gravel Pit #1 Property is provided in this letter. We hope this information meets your goals regarding potential purchase of this Property. Please feel free to contact me with any questions angief@sgm-inc.com / 970.384.9027. I look forward to hearing from you soon. Sincerely, SGM Angie Fowler, PE Project Manager www.sgm-inc.com GLENWOOD SPRINGS 118 West Sixth St, Suite 200 | Glenwood Springs, CO 81601 | 970.945.1004 2 Wetlands Delineation Finding The National Wetlands Inventory (NWI) provides the user with information to conduct an initial desktop assessment and generate maps for an area of interest. The NWI for the Rifle Pit #1 property (Property) indicated that most of the area is wetlands (Figure 1). A site visit and delineation performed by SGM on July 17, 2019 generally confirmed that this parcel contains large areas of wetlands, although not as extensive as suggested by the NWI (Figure 2). The wetland areas are concentrated on the west end of the property and are well-developed and relatively high-quality from a biological and functional perspective. The east end is mesic pasture meadow rather than jurisdictional wetlands, and development of the gravel resources in this area could be accomplished without Section 404 permits. Parcel Geology The Parcel is underlain by river gravels which are saturated and in direct contact with the water table. The surface soil is generally an alluvial silty clay loam, with areas of heavy clay. Boring logs and direct observation suggest that many areas of wetland vegetation are underlain by a clay aquitard layer at a depth of approximately three feet. The site visit and supplemental subsurface documentation suggests that the wetlands are supported primarily by surface water discharge onto the property via pooling of that water on the shallow clay aquitards. Shallow groundwater may be supplementing the wetland hydrology in some areas, but drilling data suggest that the water table is approximately seven feet below the surface across most of the Parcel, and that 3 or 4 feet of dry gravel underlies the clay pans and wetlands. Surface water reaches the property exclusively via artificially-excavated channels off the Last Chance Ditch. This includes the large lateral/tailwater ditch that bisects the property from east to west, and several smaller ditches that discharge underneath the interstate and onto the southern boundary of the property (Figure 3). Based on this understanding of the hydrology, if the tailwater seepage and direct discharge onto the property are stopped (by closing headgates, re-routing and/or piping the ditches, or other similar methods), the primary water source for the wetlands could be removed. Groundwater modeling also suggests that pit dewatering activities in adjacent upland areas (east) will significantly and rapidly depress groundwater levels throughout the Parcel, further isolating the wetlands from groundwater hydrology (See attached Letter Report, Hahn Water Resources, LLC, August 2, 2019). The combination of pit dewatering adjacent to the wetlands, and removal of irrigation-derived water discharges onto the property, could remove the hydrology supporting the wetlands throughout the Parcel, and will likely result in the loss of wetland status within two growing seasons. Army Corps Section 404 Permitting Considerations The Army Corps of Engineers (Army Corps) regulates the discharge of sediment into wetlands through Section 404 of the Clean Water Act. The eastern portion of the Parcel does not contain jurisdictional waters or wetlands, and development could proceed in that location without Section 404 permitting. SGM’s site investigation completed on July 17, 2019 would be formalized in a wetland delineation report if the property is purchased which would provide confirmation of regulatory compliance for the initial development activities. www.sgm-inc.com 3 The NWI mapping, which shows much of the western portion of the Parcel as wetlands, means that prior to developing those areas, the burden of proof would be on Scott Contracting to prove to the Army Corps that the wetlands are either (a) supported entirely by irrigation water and therefore non-jurisdictional, or (b) no longer wetlands. In general, no more than 0.5 acres of direct wetland impact can be permitted without going through the extensive Army Corps Individual Permit process, which is incompatible with effective development on the Parcel. However, documenting that the Parcel no longer contains wetland characteristics would allow full development on the site. Removing irrigation and upstream flows from being directed on the Parcel and documenting a loss of wetland conditions are the most common way to accomplish this goal. In addition, groundwater pumping is not regulated by Section 404, and indirect impacts to wetlands due to an adjacent pit dewatering operation are not regulated by Section 404 either (Army Corps, T. Morse, pers. comm.). Therefore, although initial gravel pit dewatering in the eastern portion of the property will depresses groundwater in adjacent wetlands and contribute to a loss of wetland conditions, that activity is not regulated and does not require a permit under Section 404. A dewatering permit from the Colorado Department of Public Health and Environment (CDPHE) – Water Quality Control Division (WQCD) is, however required for dewatering operations. Recommendations Based upon these initial wetland and groundwater modeling evaluations, we recommended that Scott Contracting proceed with a two-pronged approach to remove the hydrology which supports wetlands on the Parcel: · Remove all irrigation water discharge onto the property · Maintain dewatering in a pit located in the upland eastern portion of the property, which could depress groundwater throughout the property. Monitoring of wetland conditions on a quarterly or bi-annual basis would allow Scott Contracting to document that all activities are in compliant with Section 404 regulations and would also document the point at which wetlands disappear from some or all the Parcel. At that point Scott Contracting could apply to the Army Corps for an Approved Jurisdictional Determination (AJD), which would formally recognize that the NWI wetlands are no longer present, and that development of the remainder of the property can proceed without Section 404 permitting. www.sgm-inc.com 4 Figures Figure 1. NWI Wetlands Map. Figure 2. Initial Wetlands Mapping by SGM (July 17, 2019). www.sgm-inc.com 5 Figure 3. Location of Irrigation Laterals, Ditches, and Other Drainages. www.sgm-inc.com Dewatering Report Hahn Water Resources, llc ________________________________________________________________________ 1 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com August 2, 2019 Angie Fowler, PE SGM 118 W Sixth St, Suite 200 Glenwood Springs, CO 81601 Letter Report: Evaluation of the Impacts of Dewatering at Rifle Pit No. 1 BACKGROUND AND OBJECTIVES This letter report provides a brief summary of my findings in an investigation of the impacts of dewatering of a proposed sand and gravel mine known as the Rifle Pit No. 1. The proposed mine is located in Garfield County, Colorado within the alluvial channel of the Colorado River. The effects of dewatering are of interest in terms of how they might impact several areas on the property that have been identified as wetlands. METHODS OF INVESTIGATION Basic Data Site-specific data available for this analysis was extremely limited. That data included drilling logs and water level measurements for 5 exploratory borings (HP Geotech, 2008), a site elevation survey, preliminary mapping of on-site wetlands, mapping of various ditches and laterals surrounding and traversing the property, a decree for water rights on an adjacent parcel that included a discussion of aquifer properties (SGM, 2019). and aerial imagery (Google Earth and NAIP imagery). Model Selection It was determined that a numerical model would be best suited for making the types of predictions required. Whereas analytical solutions can, in some instances, provide more precise solutions, they have difficulty representing the multiple boundary conditions that need to be addressed in this setting. It was further determined that given the very limited data available for the site, the model would need to be relatively simple in its representation of the hydrogeologic system. MODFLOW-2000 (Harbaugh, et. al., 2000) was selected as the modeling platform. MODFLOW is a three dimensional, finite-difference groundwater model developed by the U. S. Geological Survey. The model was constructed with the following attributes: Model Layering The model was constructed as a single layer model representing an aquifer consisting of coarse and highly permeable alluvial sands and gravels. The sands and gravels overlie claystone/siltstone bedrock. The bedrock is treated as an impermeable boundary. Considering the limited information on the underlying bedrock (depth, elevation), the aquifer was represented as being horizontal, with a flat bottom. Hahn Water Resources, llc ________________________________________________________________________ 2 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Model Domain The model domain is square, measuring 7,000 feet x 7,000 feet. Model cells measure 100 feet x feet. The model grid is aligned in a north-south direction. Aquifer Properties The principal aquifer properties of interest in this investigation are:  Saturated thickness (b) – the thickness of the saturated porous medium measured as the difference between the static water level and the base of the aquifer, measured in feet. The model was based on an average saturated thickness of 18 feet.  Hydraulic conductivity (K) – a measure of the capacity of a porous medium to transmit a volume of water through a unit cross-sectional area, typically expressed in units of feet per day. The aquifer was assigned a uniform hydraulic conductivity of 1,000 feet per day.  Storage coefficient or specific yield (Sy) – the volume of water released from a unit volume of saturated aquifer per unit decline in head, expressed as a fraction. The aquifer was assigned a uniform value of 0.2 for specific yield.  Transmissivity (T) – a measure of the capacity of a porous medium to transmit a volume of water through the entire saturated thickness, expressed in units of feet2 per day. Transmissivity is obtained by multiplying the hydraulic conductivity by the saturated thickness (T = K x b). Transmissivity was therefore set equal to 18,000 feet2 per day. Boundary Conditions The northern edge of the model coincides with the Colorado River. The river is modeled using the “river package” of MODFLOW. The southern edge of the model terminates at the first apparent river terrace above the floodplain. This feature is mapped as a no-flow boundary (no water can enter or leave the model through this boundary). The eastern and western boundaries of the model are modeled using the “general-head boundary package” of MODFLOW. This type of boundary condition allows for movement into and out of the model, based on the difference between groundwater levels that are predicted to occur within the model domain and groundwater levels that are specified for locations outside of the model’s domain. Recharge It is understood that any surface water runoff, tail water from ditches and laterals, irrigation return flows, and other sources of surface water entering the site will be re-routed in advance of the mining. The Last Chance Ditch lateral (mapped as entering the site along the eastern boundary) will likely be routed into the dewatering trench. In light of these plans, there are no sources of surface water that were modeled as entering the groundwater system on site. Rainfall recharge was set at approximately 10 percent of total rainfall, and represents the net recharge to the groundwater system. The Last Chance Ditch (running approximately east-west through the southern portion of the model was assumed to leak water, with leakage ultimately recharging the groundwater system. Leakage from this ditch was modeled as a constant value of approximately 20,000 cubic feet per day over the portion of the canal lying within the model domain. Hahn Water Resources, llc ________________________________________________________________________ 3 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Dewatering System Dewatering of the Rifle Pit No. 1 will be accomplished with a perimeter trench running along the northern and western edges of the pit. The trench will be excavated approximately 4 feet into the underlying bedrock. Water accumulating in the trench will be pumped out of the trench and conveyed offset, ultimately discharging to the Colorado River. The dewatering system was represented using the “drain” package. The drain representation requires that an elevation be specified for the drain invert. The model then compares the elevation of the adjacent groundwater to the invert elevation. If the groundwater elevation exceeds the invert elevation, the model causes groundwater to move to the drain (where it is subsequently removed from the groundwater system). The dewatering system is modeled as being fully installed and fully operational at the start of the simulation. Model Stress Periods The model was set up as a transient, 3-year simulation, consisting of 99 stress periods of equal length of 10 days, and a final stress period of 105 days. RESULTS The model predicts a rapid response of groundwater levels to the dewatering. The following figure (Figure 1) shows the predicted groundwater level decline as a function of time (hydrograph) at a location near the western edge of the pit. The water level hydrograph indicates that most of the groundwater level response will occur within the first 60 days of the initiation of dewatering. The hydrograph also indicates that groundwater level response will reach a near- equilibrium condition within about 150 days of the start of dewatering. Dewatering will most likely be developed in stages, over time, as the pit is advanced. Accordingly, water level response times could differ significantly from those predicted in response to a fully developed dewatering system that is fully operational from the start of mining. Figure 1. Predicted Groundwater Level Decline vs. Time in Response to Dewatering Hahn Water Resources, llc ________________________________________________________________________ 4 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Figure 2 (below) shows the model-predicted groundwater level decline (drawdown) in plan view. The semi-concentric circles (with white labels) indicate lines of equal water level decline in feet, predicted at 100 days following the start of dewatering. The model predicts that the water level lowering will be laterally extensive. This behavior is consistent with a highly permeable system as exists at the Rifle No. 1 pit. Figure 2. Contours of Groundwater Level Lowering (Drawdown) Following 90 Days of Dewatering To the extent that the on-site wetlands are dependent on the underlying groundwater system, it is likely that these wetlands will disappear in a relatively short period of time (months to years) following the onset of dewatering. To the extent that such wetlands depend on an influx of surface or near-surface water (tail water, irrigation returns, etc.), the current plans to intercept these inflows will also likely result in the disappearance of the wetlands in a relatively short period of time. Respectfully submitted, William F. Hahn, P.G. Hahn Water Resources, llc ________________________________________________________________________ 5 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com REFERENCES District Court, Water Division 5, 2007. Judgment and Decree in Case No. 06CW121 Concerning the Application for Water Rights of Gypsum Ranch Co, LLC and Silt Sand & Gravel, LLC. Harbaugh, Arlen W., Edward R. Banta, Mary C. Hill, and Michael G. McDonald, 2000. MODFLOW-2000, the U.S. Geological Survey Modular Ground-water Model. USGS Open-File Report 00-92. HP Geotech, 2008. Location and Logs of Exploratory Borings drilled June 26 and 30, 2008. Job No. 108 354A SGM, 2019. Miscellaneous data, including site elevation survey, preliminary mapping of wetlands, boundary information, gradation analysis for multiple pit samples. June 26, 2020 1 Wetlands Delineation Finding Fill and dredging within Waters of the U.S. and tributary wetlands are regulated by the US Army Corps of Engineers (USACE) under Section 404 of the Clean Water Act (CWA). The National Wetlands Inventory (NWI) provides the user with information to conduct an initial desktop assessment and generate maps of the potential extent of jurisdictional waters for any area of interest. As a national-level dataset, the NWI is not and cannot be entirely accurate at a local level and should always be evaluated against a field-based study of conditions on the site. The NWI for the Rifle Pit #1 property (Property) indicates that the area consists of a mosaic of upland areas interspersed with wetland zones dominated by herbaceous emergent vegetation (Figure 1). A site visit and delineation performed by SGM on July 17, 2019 generally confirmed that this parcel contains large areas of wetlands dominated by cattail and bulrush emergent communities, although these areas are not as extensive as suggested by the NWI (Figure 2). The wetland areas are concentrated on the west end of the property and are well-developed and relatively high-quality from a biological and functional perspective. The east end is mesic pasture meadow rather than jurisdictional wetlands, and development of the gravel resources in this area could be accomplished without Section 404 permits or impacts to Waterbodies protected by the Garfield County Land Use Development Code (LUDC).The Last Chance Ditch enters the Property from the east; this is an artificially-excavated, gated and controlled irrigation ditch and as such is explicitly excluded from consideration as a protected Waterbody in the LUDC. The Last Chance Ditch and its laterals discharge tailwaters onto the surface of the Property, at numerous locations. Parcel Geology Boring logs (HP Geotech, 2008) and direct observation indicate that the entire Property is underlain by a consistent subsurface column consisting of (a) silty clay loam from the surface to a depth of 3 feet, (b) an impermeable clay aquitard layer at a depth of approximately 3 feet, (c) dry gravel to a depth of approximately 7 feet, and (d) saturated gravels in direct contact with the water table starting at a depth of 7 feet (see Land Use Permit Application, May 2020). The site visit and supplemental subsurface documentation suggests that the wetlands are supported entirely by irrigation tailwater discharge onto the Property, which pools on the shallow clay aquitards and forms a perched zone of saturation above dry gravel. There is no indication of natural surface hydrology on the Property: surface water reaches the property exclusively via artificially-excavated channels off the Last Chance Ditch, including the large lateral/tailwater ditch that bisects the property from east to west, and several smaller ditches that discharge underneath the interstate and onto the southern boundary of the property (Figure 3). The available drilling data consistently show that the water table is approximately 7 feet below the surface, and that 3 or 4 feet of dry gravel intervene between the zone of surface saturation and groundwater. Based on this understanding of the hydrology, if the tailwater discharge onto the property are stopped (by closing headgates, re-routing and/or piping the ditches, or other similar methods), the primary water source for the wetlands will be removed. Groundwater modeling also suggests that pit dewatering activities in adjacent upland areas (east) will significantly and rapidly depress groundwater levels throughout the Property, further isolating the wetlands from groundwater hydrology (See attached Letter Report, Hahn Water Resources, LLC, August 2, 2019 and July 8, 2020). 2 The combination of pit dewatering adjacent to the wetlands, and removal of irrigation-derived water discharges onto the property, are expected to remove the hydrology supporting the wetlands throughout the Parcel. It is expected that the areas currently mapped as wetlands per the USACE and LUDC criteria (Figure 2) will cease to display wetland hydrology and/or hydrophytic vegetation within two growing seasons and will no longer meet the criteria as wetlands under USACE jurisdiction or as Waterbodies under LUDC definitions. Army Corps Section 404 Permitting Considerations The USACE regulates the discharge or dredging of sediment into wetlands, including activities such as the commercial development of gravel resources, however wetlands supported entirely by irrigation water (a.k.a. agriculturally induced wetlands) are not regulated. The eastern portion of the Parcel does not contain jurisdictional waters or wetlands, and development can proceed in this area without further Section 404 permitting considerations. SGM’s site investigation completed on July 17, 2019 will be formalized in a wetland delineation report to provide confirmation of regulatory compliance, once development of the gravel operation is approved and the precise extent and nature of the initial development activities are determined. In addition, groundwater pumping is not regulated by the USACE, nor are indirect impacts to wetlands due to an adjacent pit dewatering operation (USACE, T. Morse, pers. comm.). Therefore, although initial gravel pit dewatering in the eastern portion of the property will depresses groundwater in adjacent wetlands and contribute to a loss of wetland conditions, that activity is not regulated and does not require a permit under Section 404. Dewatering permits from the Colorado Department of Public Health and Environment (CDPHE) – Water Quality Control Division (WQCD) and the Division of Water Resources (DWR) are required for dewatering operations. The NWI mapping, which shows much of the western portion of the Parcel as wetlands, means that prior to developing those areas, the burden of proof is on Scott Contracting to prove to the USACE that the wetlands are either (a) supported entirely by irrigation water and therefore non-jurisdictional, or (b) no longer meeting the regulatory definition of wetlands. In general, no more than 0.5 acres of direct wetland impact can be permitted without going through the extensive USACE Individual Permit process, therefore seeking a permit for impact to the wetlands is incompatible with effective development on the Parcel. However, documenting that the Parcel no longer contains wetland characteristics will allow full development on the site. Based on the underlying hydrology and geology described above, Scott Contracting believes that by removing irrigation tailwater discharge from the Property and rerouting the Last Chance Ditch and laterals, will remove the sole water source for the wetlands and result in the loss of wetland characteristics. Scott will monitor and document the change in wetland conditions and will seek formal confirmation of the findings from the USACE via an Approved Jurisdictional Determination. Once the USACE has formally recognized that the removal of irrigation water has resulted in the loss of wetland criteria, indicating that the wetlands are agriculturally induced, Scott Contracting will proceed to develop the remaining portion of the Property. Garfield County Wetland Impact Considerations Garfield County’s definition of “wetland” relies on the same fundamental criteria as the USACE: the presence of continuous or reoccurring saturation/inundation, the development of chemical signatures in the 3 soil that indicate anaerobic conditions typical of long-term saturation (i.e. “hydric soils”), and the dominance of plant species that depend on saturated soils (i.e. “hydrophytic vegetation”). Therefore, the wetland delineation performed for the Property (Figure 2) accurately describes the extent of wetlands/Waterbodies under the LUDC, as well as under the CWA. However, unlike the CWA the LUDC does not distinguish between wetlands supported by natural hydrology and those that are agriculturally-induced, and in fact the LUDC explicitly requires the disclosure of impacts to wetlands, regardless of “whether or not they are jurisdictional as defined by the Corps of Engineers [USACE]” (Article 14-401.T). Based on this reading of the LUDC, Figure 2 should be taken to indicate the extent of proposed impacts to wetlands, as required by Article 4-203.G. The proposed gravel pit operation on the Property would result in development within wetland areas and within the 35-foot buffer zone around Waterbodies, and therefore a waiver for this development is requested. The waiver request is based on the following factors: · Hydrologic studies, drilling logs, and site observations indicate that the wetlands on the site are supported by irrigation water rather than natural hydrology. · The proposed gravel operation is not logistically feasible without re-routing the current tailwater ditches and initiating groundwater pumping to dewater the pit, which would remove the irrigation water supporting the wetlands. · The development of the initial phase of the gravel operation, confined to the eastern portion of the Property outside of wetland areas, is expected to result in the loss of wetlands from the remainder of the Property. · The proposed gravel operation is financially feasible only if most of the Property is developed, including the areas of agriculturally induced wetlands. · The reclamation of the site would produce habitat value that would replace the lost values to some extent, since the gravel pond would support a wetland fringe on its periphery. These wetlands would be supported by natural groundwater rather than irrigation tailwaters, and therefore would be protected under the CWA. Recommended Monitoring & Development Based upon the wetland and groundwater modeling evaluations performed to date, Scott Contracting will proceed with the two-pronged approach to remove the hydrology which supports wetlands on the Parcel, while remaining in compliance with the CWA and the LUDC: 1. Remove all irrigation water discharge onto the property by rerouting the Last Chance Ditch to the northern boundary of the Property (See Drawings attached to NTC Letter) 2. Maintain dewatering in the initial pit development, to be in the upland eastern portion of the Property, which will depress groundwater throughout the Property. SGM will monitoring wetland conditions on a quarterly basis, using the standard USACE wetland delineation protocols to track the response of the hydrology and vegetation to the altered hydrology. Quarterly reports will contain conditions assessments and maps of the evolving extent of wetland areas, and the results will be shared with the USACE on a regular basis. Physical boundary indicators (such as earthen berms or silt fence) will be maintained to prevent any inadvertent transgression into areas that retain wetland characteristics during the initial phases of development. The quarterly reports will allow Scott Contracting 4 to document that all ongoing activities follow Section 404 regulations and would also document the point at which wetlands disappear from some or all the Property. At the point when monitoring indicates an unambiguous loss of wetland characteristics from the Property, Scott Contracting will submit the revised delineation results to the USACE and request an Approved Jurisdictional Determination (AJD), which would formally recognize that the NWI wetlands are no longer present, and that development of the remainder of the property can proceed without Section 404 permitting. Figures Figure 1. NWI Wetlands Map. 5 Figure 2. Initial Wetlands Mapping by SGM (July 17, 2019). 6 Figure 3. Location of Irrigation Laterals, Ditches, and Other Drainages. Attachment 7 www.sgm-inc.com Attachment 8 www.sgm-inc.com 1 (( Community Development Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 (970) 945-8212 www.garfield-county.com PRE-APPLICATION CONFERENCE SUMMARY TAX PARCEL NUMBER: 2179-083-00-103 PRE-APP DATE: July 15, 2020 PROJECT: Rifle Gravel Pit #1 - Scott Contracting - Floodplain Permit OWNER/APPLICANT Scott Contracting Inc. REPRESENTATIVE: Chip Fischer, SGM & Angie Fowler, SGM PRACTICAL LOCATION: Address tbd, approximately 1 mile northeast of the Rifle – Garfield County Airport off of the I-70 north frontage road SITE INFORMATION: The site is approximately 57.9 acres in size and located adjacent to the Colorado River ZONING: Rural TYPE OF APPLICATION: Floodplain Development Permit I. GENERAL PROJECT DESCRIPTION The Applicant is in the process of seeking a Land Use Change Permit for a commercial gravel pit on the 57.9 acre site. A portion of the site has been identified as being with the 100 year floodplain. Development of the site including grading and earth moving associated with the gravel pit requires approval of a Floodplain Development Permit and compliance with the Garfield County Land Use and Development Code (LUDC) standards and requirements. Issues anticipated to be addressed include floodplain, wetlands, and water body setbacks. II. REGULATORY PROVISIONS APPLICANT IS REQUIRED TO ADDRESS The following Sections of the Garfield Land Use and Development Code as amended apply to the proposed Application: • Section 3-301 – Floodplain Overlay Regulations to include 3-301(E)(3). • Section 4-109 – Development in the 100 Year Floodplain, including review criteria. 2 • Table 4-102 – Common Review Procedures and Required Notice • Table 4-201 – Submittal Requirements • Section 4-203 – Submittal Requirements as appropriate • Section 4-203 (O) – Flood Plain Analysis • Section 4-118 – Waiver from Standards (if needed) • Section 7-203(B) & (C) – Protection of Water Bodies III. ADMINISTRATIVE REVIEW PROCESS The review process shall follow a modified version of the steps contained in Table 4-102 and Section 4-103, Administrative Review (see attached flow chart). IV. SUBMITTAL REQUIREMENTS – KEY TOPICS As a convenience, outlined below is a list of information typically required for this type of application. Staff anticipates much of the information will be consistent with the overall gravel pit Land Use Change Permit which has recently been submitted. • General Application Materials o Completed application form o Completed Payment Agreement form o Authorization to represent as appropriate o Proof of Ownership (title work and deed) o Names and mailing addresses of property owners within 200 ft. of the property. o Completed Certification of Mineral Owner Research form o Project description – narrative • Copy of the pre-application summary • A Vicinity Map within approximately 3 miles • Site Plan – to applicable scale, including all proposed improvements and significant features. • Floodplain Analysis meeting the requirements of the LUDC including Sections 3-301 and 4- 203(O) as applicable. Section 3-301(E)(3) needs to be addressed confirming no drainage impacts on adjacent properties. The Flood Plain Analysis/memo needs to be completed by a qualified licensed professional engineer. Some elements may not be applicable based on the type of project. An explanation/justification in those cases should be provided. • The Application will need to include details and plans for the proposed improvements. • The Analysis will need to address the lack of any impacts from the proposed improvements (i.e. no impact on flooding potential – Zero Rise) • The Analysis will need to include information on construction practices including staging areas, stock piling areas, protection of water quality from sediment or erosion potential, equipment to be used, and revegetation plans as appropriate. • The submittals need to address compliance with the Review Criteria contained in Section 4- 109 (attached) as applicable. • The submittals need to include any other existing reports, studies, and permits including but not limited to any past review by the Army Corp of Engineers and wetlands analyses. • The submittals need to generally address compliance with Section 7-203 (B), Protection of Water Bodies, Structures Permitted in Setbacks. Any significant removal of vegetation should be addressed in the submittals with waivers requested if needed. 3 Follow-up conversations with Staff and/or our Consulting Engineering are options if additional questions come up regarding the submittal requirements. As noted above some elements of the Flood Plain Analysis may not be applicable and the Application submittals can reflect that representation. The Application submittal needs to include 3 hard copies of the entire Application and 1 Digital PDF Copy of the entire Application (on a CD or USB Stick). Both the paper and digital copies should be split into individual sections and properly labeled. Please refer to the pre-application summary for submittal requirements that are appropriate for your Application. V. APPLICATION REVIEW a. Review by: Staff for completeness recommendation and referral agencies for additional technical review b. Public Hearing: _X_ Director Decision with notice ___ Planning Commission ___ Board of County Commissioners ___ Board of Adjustment VI. APPLICATION REVIEW FEES a. Planning Review Fees: $ 400.00 b. Referral Agency Fees: $ TBD (Fees associated with consulting engineer review) c. Total Deposit: $ 400.00 (additional hours are billed at $40.50 /hour) VII. GENERAL APPLICATION PROCESSING The foregoing summary is advisory in nature only and is not binding on the County. The summary is based on current zoning, which is subject to change in the future, and upon factual representations that may or may not be accurate. This summary does not create a legal or vested right. The summary is valid for a six month period, after which an update should be requested. The Applicant is advised that the Application submittal once accepted by the County becomes public information and will be available (including electronically for review by the public. Proprietary information can be redacted from documents prior to submittal. PRE-APPLICATION SUMMARY PREPARED BY: __________________________________________________ ___7/15/20__________ Glenn Hartmann, Principal Planner Date 4 NOTE: Notice requirements is 15 days prior to the Director’s Decision August 27, 2020 Angie Fowler, SGM Inc. Chip Fisher, SGM Inc. 118 W. Sixth Street Glenwood Springs, CO 81601 RE: Completeness Review Scott Contracting Floodplain Development Permit (File No. FDPA-08-20-8801) Dear Angie and Chip: Thank you for the detailed submittals that you have provided for the Scott Contracting Inc. Floodplain Development Permit Application. Our completeness review included input from the County Attorney’s Office and has identified some items that will need to be addressed prior to a determination of technical completeness. Please respond to the following items: 1. At the request of the County Attorney’s Office, please provide an updated title commitment as it is over a year old. 2. Please provide additional specific responses to each Review Criteria contained in Section 4-109 (C). 3. Please provide additional responses to Section 3-301 in particular the following need to be addressed: - Compliance with General and Specific Standards for non-residential construction and placement of manufactured structures, anchoring or floodproofing. - Confirmation that the site is not located within the floodway. - Confirmation that drainage will not adversely impact adjacent properties (this includes the placement of the berm on the site) 4. The Floodplain Study portion of the Application needs to specifically address the requirements contained in Section 4-203 (O) or provide explanations where they may not be applicable. Of note responses are needed to the following: Community Development Department - Sheet C-1 needs to clearly label the extent of the 100 year floodplain and floodway on the site. - Elevations of the lowest floor of the proposed structure are needed or more detail demonstrating floodproofing. - A pre-construction elevation certificate needs to be provided, as appropriate. 5. Please double check your mailing lists to confirm that all owners for Parcel No. 2179-083-00-102 are listed. Once the above items are addressed, we can schedule a date for your Director’s Decision. An addendum/supplement to your submittal would be an acceptable and efficient way to include your responses in the file. If further explanation of the above items would be of assistance a supplemental meeting with staff is suggested. Please note that the Garfield County Land Use and Development Code requires that the technical completeness issues be resolved within 60-days of the date of this letter, otherwise the application will be deemed withdrawn unless a request for extension is submitted and approved. Please feel free to contact me with any questions. Sincerely, Glenn Hartmann Principal Planner Attachment 9 www.sgm-inc.com Hahn Water Resources, llc ________________________________________________________________________ 1 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com August 2, 2019 Angie Fowler, PE SGM 118 W Sixth St, Suite 200 Glenwood Springs, CO 81601 Letter Report: Evaluation of the Impacts of Dewatering at Rifle Pit No. 1 BACKGROUND AND OBJECTIVES This letter report provides a brief summary of my findings in an investigation of the impacts of dewatering of a proposed sand and gravel mine known as the Rifle Pit No. 1. The proposed mine is located in Garfield County, Colorado within the alluvial channel of the Colorado River. The effects of dewatering are of interest in terms of how they might impact several areas on the property that have been identified as wetlands. METHODS OF INVESTIGATION Basic Data Site-specific data available for this analysis was extremely limited. That data included drilling logs and water level measurements for 5 exploratory borings (HP Geotech, 2008), a site elevation survey, preliminary mapping of on-site wetlands, mapping of various ditches and laterals surrounding and traversing the property, a decree for water rights on an adjacent parcel that included a discussion of aquifer properties (SGM, 2019). and aerial imagery (Google Earth and NAIP imagery). Model Selection It was determined that a numerical model would be best suited for making the types of predictions required. Whereas analytical solutions can, in some instances, provide more precise solutions, they have difficulty representing the multiple boundary conditions that need to be addressed in this setting. It was further determined that given the very limited data available for the site, the model would need to be relatively simple in its representation of the hydrogeologic system. MODFLOW-2000 (Harbaugh, et. al., 2000) was selected as the modeling platform. MODFLOW is a three dimensional, finite-difference groundwater model developed by the U. S. Geological Survey. The model was constructed with the following attributes: Model Layering The model was constructed as a single layer model representing an aquifer consisting of coarse and highly permeable alluvial sands and gravels. The sands and gravels overlie claystone/siltstone bedrock. The bedrock is treated as an impermeable boundary. Considering the limited information on the underlying bedrock (depth, elevation), the aquifer was represented as being horizontal, with a flat bottom. Hahn Water Resources, llc ________________________________________________________________________ 2 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Model Domain The model domain is square, measuring 7,000 feet x 7,000 feet. Model cells measure 100 feet x feet. The model grid is aligned in a north-south direction. Aquifer Properties The principal aquifer properties of interest in this investigation are:  Saturated thickness (b) – the thickness of the saturated porous medium measured as the difference between the static water level and the base of the aquifer, measured in feet. The model was based on an average saturated thickness of 18 feet.  Hydraulic conductivity (K) – a measure of the capacity of a porous medium to transmit a volume of water through a unit cross-sectional area, typically expressed in units of feet per day. The aquifer was assigned a uniform hydraulic conductivity of 1,000 feet per day.  Storage coefficient or specific yield (Sy) – the volume of water released from a unit volume of saturated aquifer per unit decline in head, expressed as a fraction. The aquifer was assigned a uniform value of 0.2 for specific yield.  Transmissivity (T) – a measure of the capacity of a porous medium to transmit a volume of water through the entire saturated thickness, expressed in units of feet2 per day. Transmissivity is obtained by multiplying the hydraulic conductivity by the saturated thickness (T = K x b). Transmissivity was therefore set equal to 18,000 feet2 per day. Boundary Conditions The northern edge of the model coincides with the Colorado River. The river is modeled using the “river package” of MODFLOW. The southern edge of the model terminates at the first apparent river terrace above the floodplain. This feature is mapped as a no-flow boundary (no water can enter or leave the model through this boundary). The eastern and western boundaries of the model are modeled using the “general-head boundary package” of MODFLOW. This type of boundary condition allows for movement into and out of the model, based on the difference between groundwater levels that are predicted to occur within the model domain and groundwater levels that are specified for locations outside of the model’s domain. Recharge It is understood that any surface water runoff, tail water from ditches and laterals, irrigation return flows, and other sources of surface water entering the site will be re-routed in advance of the mining. The Last Chance Ditch lateral (mapped as entering the site along the eastern boundary) will likely be routed into the dewatering trench. In light of these plans, there are no sources of surface water that were modeled as entering the groundwater system on site. Rainfall recharge was set at approximately 10 percent of total rainfall, and represents the net recharge to the groundwater system. The Last Chance Ditch (running approximately east-west through the southern portion of the model was assumed to leak water, with leakage ultimately recharging the groundwater system. Leakage from this ditch was modeled as a constant value of approximately 20,000 cubic feet per day over the portion of the canal lying within the model domain. Hahn Water Resources, llc ________________________________________________________________________ 3 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Dewatering System Dewatering of the Rifle Pit No. 1 will be accomplished with a perimeter trench running along the northern and western edges of the pit. The trench will be excavated approximately 4 feet into the underlying bedrock. Water accumulating in the trench will be pumped out of the trench and conveyed offset, ultimately discharging to the Colorado River. The dewatering system was represented using the “drain” package. The drain representation requires that an elevation be specified for the drain invert. The model then compares the elevation of the adjacent groundwater to the invert elevation. If the groundwater elevation exceeds the invert elevation, the model causes groundwater to move to the drain (where it is subsequently removed from the groundwater system). The dewatering system is modeled as being fully installed and fully operational at the start of the simulation. Model Stress Periods The model was set up as a transient, 3-year simulation, consisting of 99 stress periods of equal length of 10 days, and a final stress period of 105 days. RESULTS The model predicts a rapid response of groundwater levels to the dewatering. The following figure (Figure 1) shows the predicted groundwater level decline as a function of time (hydrograph) at a location near the western edge of the pit. The water level hydrograph indicates that most of the groundwater level response will occur within the first 60 days of the initiation of dewatering. The hydrograph also indicates that groundwater level response will reach a near- equilibrium condition within about 150 days of the start of dewatering. Dewatering will most likely be developed in stages, over time, as the pit is advanced. Accordingly, water level response times could differ significantly from those predicted in response to a fully developed dewatering system that is fully operational from the start of mining. Figure 1. Predicted Groundwater Level Decline vs. Time in Response to Dewatering Hahn Water Resources, llc ________________________________________________________________________ 4 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Figure 2 (below) shows the model-predicted groundwater level decline (drawdown) in plan view. The semi-concentric circles (with white labels) indicate lines of equal water level decline in feet, predicted at 100 days following the start of dewatering. The model predicts that the water level lowering will be laterally extensive. This behavior is consistent with a highly permeable system as exists at the Rifle No. 1 pit. Figure 2. Contours of Groundwater Level Lowering (Drawdown) Following 90 Days of Dewatering To the extent that the on-site wetlands are dependent on the underlying groundwater system, it is likely that these wetlands will disappear in a relatively short period of time (months to years) following the onset of dewatering. To the extent that such wetlands depend on an influx of surface or near-surface water (tail water, irrigation returns, etc.), the current plans to intercept these inflows will also likely result in the disappearance of the wetlands in a relatively short period of time. Respectfully submitted, William F. Hahn, P.G. Hahn Water Resources, llc ________________________________________________________________________ 5 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com REFERENCES District Court, Water Division 5, 2007. Judgment and Decree in Case No. 06CW121 Concerning the Application for Water Rights of Gypsum Ranch Co, LLC and Silt Sand & Gravel, LLC. Harbaugh, Arlen W., Edward R. Banta, Mary C. Hill, and Michael G. McDonald, 2000. MODFLOW-2000, the U.S. Geological Survey Modular Ground-water Model. USGS Open-File Report 00-92. HP Geotech, 2008. Location and Logs of Exploratory Borings drilled June 26 and 30, 2008. Job No. 108 354A SGM, 2019. Miscellaneous data, including site elevation survey, preliminary mapping of wetlands, boundary information, gradation analysis for multiple pit samples. Hahn Water Resources, llc ________________________________________________________________________ 1 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com July 8, 2020 Angie Fowler, PE SGM 118 W Sixth St, Suite 200 Glenwood Springs, CO 81601 Supplement to Hahn Water Resources Letter Report of August 2, 2019 on an Evaluation of the Impacts of Dewatering at Rifle Pit No. 1 This report presents supplemental findings to those in my August 2, 2019 letter report to you on the impacts of dewatering at the Rifle Pit No. 1. The Rifle Pit No. 1 is a proposed sand and gravel mine located in Garfield County, Colorado within the alluvial channel of the Colorado River. SGM filed a permit application to the Colorado Division of Reclamation, Mining and Safety (DRMS) entitled “Construction Materials Regular (112) Operation Reclamation Permit Application” (Application) in January 2020. SGM received comments to the Application from DRMS (through Scott Contracting, Inc.) and from Garfield County. Those comments included questions related to the proposed dewatering activities. This report is intended to address questions and requests for additional information contained in the DRMS and Garfield County responses to the Application. Dewatering Concepts The initial goal of my investigation was to evaluate the expected changes in on-site and off-site groundwater levels that would accompany the dewatering activities. Changes in groundwater levels were of particular interest in terms of their impacts to on-site wetlands. A numerical groundwater flow model (MODFLOW) was used to estimate water level impacts from pit dewatering with an emphasis on water level change that would result from dewatering rather than on a specific dewatering system and its performance. Site-specific data available for this analysis was extremely limited. That data included drilling logs and water level measurements for 5 exploratory borings (HP Geotech, 2008), a site elevation survey, preliminary mapping of on-site wetlands, mapping of various ditches and laterals surrounding and traversing the property, a decree for water rights on an adjacent parcel that included a discussion of aquifer properties, and aerial imagery. The dewatering was modeled as if it were accomplished with a fully penetrating perimeter drain. The model predicted a pit inflow rate of about 7 cubic feet per second (cfs) or about 3,000 gallons per minute (gpm) under steady-state conditions. In this case, steady state conditions represent the point in time following an extended period of dewatering when inflow rates have leveled off. Given the absence of site-specific information on aquifer properties, there is significant uncertainty in these predicted inflow rates. Hahn Water Resources, llc ________________________________________________________________________ 2 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com As the mining plans have been refined, the dewatering concept was modified such that the dewatering will be accomplished with a series of wells. Whereas the dewatering concept has not yet been finalized, for purposes of my investigation the concept now includes a series of wells surrounding the pit. These wells would be augmented with perimeter drains as needed to capture seepage that may enter the pit in areas at seepage faces, or other areas where the seepage cannot be intercepted by wells. The perimeter drains would extend a short distance below the floor of the pit. Locations of the drains cannot be predicted in advance – these would likely be installed on an as-needed basis as the mining advances and would be removed when no longer needed for dewatering. In some instances, water collecting on the floor of the mine may be removed with portable pumps that are repositioned as needed to remove seepage water. Discharge from the perimeter drains and portable pumps would be combined with discharge from the wells prior to conveyance to the river. Although the Application identified a single well located near the western edge of the pit to accomplish the dewatering, the actual dewatering system would likely consist of multiple wells combined with a perimeter drain. It is important to note that the dewatering system described herein represents a concept only and should not be relied upon for design/construction of the dewatering system. The dewatering concept was developed to allow a “planning-level” investigation of probable water level impacts and dewatering flow rates. I recommend engaging a dewatering contractor who would make further investigation of subsurface conditions, design the dewatering system, and refine estimates of the timing and rates of inflow to be expected during dewatering activities. Supplemental Findings Performance of the conceptual dewatering system was evaluated in terms of expected discharge rates during dewatering and the effects on groundwater levels during the mining period and post- mining. This investigation made use of the numerical model developed during my initial investigation, modified to simulate wells rather than a fully penetrating perimeter drain. I also made use of an analytical model as an independent check on the solution provided by the numerical model. My analysis assumed that dewatering would be accomplished with 8 wells approximately evenly spaced around the perimeter of the mine. I adjusted pumping rates to achieve near-complete dewatering of the sediments to be mined. I did not attempt to balance the number of wells and the discharge rates of those wells relative to the efficiency of the dewatering scheme. The current investigation suggests that dewatering could be accomplished with wells operating at a combined discharge rate of about 7 cfs or about 3,000 gpm. These results agree with findings of my earlier investigation. For this analysis, it was assumed that dewatering would be continuous over an estimated 5-year life of the mine. Figure 1 shows the predicted water levels at a location near the western edge of the pit. As seen in this figure, groundwater levels drop relatively quickly, approaching steady-state water levels in about 6 months. Water levels are predicted to stabilize in about 12 months. This figure also shows that groundwater levels recover Hahn Water Resources, llc ________________________________________________________________________ 3 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com quickly following the cessation of dewatering, returning to pre-mining levels within about 6 months. Figure 1. Predicted Groundwater Level Decline vs. Time in Response to Dewatering Figure 2 (below) shows the model-predicted groundwater level decline (drawdown) in plan view as predicted for a dewatering system consisting of wells. The semi-concentric circles (with white labels) indicate lines of equal water level decline in feet, predicted at the end of 5 years of continuous dewatering. The model predicts that the water level lowering will be laterally extensive. This behavior is consistent with a highly permeable system as exists at the Rifle No. 1 pit. Figure 2. Contours of Groundwater Level Lowering (Drawdown) Following 5 Years of Dewatering Hahn Water Resources, llc ________________________________________________________________________ 4 6589 Elaine Road ∙Evergreen, Colorado 80439 ∙ office 720.242.8639 ∙ cell: 303.870.5757 hahnwaterresources@gmail.com ∙ www.hahnwaterresources.com Seasonal variations in the performance of the dewatering system are expected to be relatively minor. Groundwater levels in the alluvial aquifer, the target of the dewatering, are expected to track water levels in the Colorado River. River stage is estimated to vary over the course of a year by about 3 feet, with the exception of the month of June. Snowmelt runoff typically peaks in June, when river stage may peak at 5 feet or more above average. Changes in groundwater levels may require slightly more pumping to achieve the equivalent water level drawdown, or they may limit the depth to which mining can advance while the groundwater levels are elevated. Peaks in river stage typically last less than one month. Respectfully submitted, William F. Hahn, P.G.