Loading...
HomeMy WebLinkAbout4.0 BOCC Staff Report 03.16.1998Ponderosa subdivision exhibits BOCC 3/16/98 Exhibit Explanation A. Proof of publication B. Certified mailing receipts C. Application with all attachments and supplements D. Project information and staff comments with all attachments E. Copy of the Garfield county subdivision regulations of 1984, as amended F. Copy of the Garfield county zoning resolution of 1978, as amended G. Copy of the Garfield county comprehensive plans of 1981 and 1984 BOCC 3/16/98 PROJECT INFORMATION AND STAFF COMMENTS REQUEST: Preliminary Plan consideration of the Ponderosa Subdivision. APPLICANT: Kenneth (Scott) Rose LOCATION: A tract of land located within Section 5, T5S, R93W of the 6th P.M.; located approximately 10 miles northwest of the City of Rifle, along State Highway 13. SITE DATA: 8.56 Acres WATER: Shared spring/shared well SEWER: Individual sewage disposal systems ACCESS: Direct access to State Highway 13 EXISTING ZONING: A/R/RD ADJACENT ZONING: North/East: O/S South/West: R/L I. RELATIONSHIP TO THE COMPREHENSIVE PLAN The subject tract is located within District C - Rural Areas/Minor Environmental Constraints, as designated by the Garfield County Comprehensive Plan's Management Districts Map. II. DESCRIPTION OF THE PROPOSAL A. Site Description: The 8.56 acre tract is located approximately 10 miles northwest of Rifle, along SH 13 and is currently utilized as a single family residential homesite, with an existing mobile home occupying the site. Slope varies across the tract and in the eastern portion exceeds 40%. However, the majority of the tract slopes at gentler angles between 2% and 20%. Vegetation appears to be native, with pinion juniper, sage and annual grasses scattered across the tract. B. Adjacent Land Uses: The area is largely devoted to single-family residential, limited agricultural and recreational land uses. See vicinity map, page c6 . Development Proposal: The applicant proposes to subdivide the 8.56 acre tract into two (2) parcels of 3.06 and 5.50 acres each. The larger parcel would contain the existing mobile home and other improvements, and the smaller parcel would be developed as a single family residential parcel. See sketch map, page III. REVIEW AGENCY/PUBLIC COMMENTS A. Garfield School District No. Re -2: Has reviewed the proposal and due to the size of the project, has no comment. See letter, page / C Book Cliff Soil Conservation District: States concerns regarding erosion and revegetation using weed -free seed, animal control, drainage, and water quality. See letter, pages 1/- J 2— . C. Division of Water Resources: Has evaluated the water supply documentation and in their opinion the supply would cause material injury to decreed water rights and would not be an adequate, physical supply. See letter, page / 3 D. Colorado Geological Survey: Has reviewed the proposal and identifies the site located upon both landslide and alluvial fan deposits. Recommends that this subdivision be investigat-d by a qualified engineering geologist, prior to any approval. See letter, pages - `J IV. MAJOR ISSUES AND CONCERNS A. Zoning: The subject tract is located within the A/R/RD zone district and both proposed lots meet the two (2) acre minimum lot size requirement. It appears that slope would not be a significant constraint to development and neither lot is within an identified, 100 -year floodplain. According to the Colorado Geological Survey, the entire subdivision site is located on geologically hazardous terrain and building envelopes should be evaluated and proposed by a qualified professional. B. Physical Water Supply: The majority of the water supply would be derived from an adjudicated spring, located east of the subdivision site, on BLM property. This supply has been evaluated over the course of the last year, both before and after development of the spring. This spring has been found to produce between 936 and 1195 gallons per day and, for the duration of the flow measurements, appears to be a continual water source. There is an existing well that may also be utilized; however, historically it has not been a reliable water source. In both the original engineering report and the letter provided by the Division of Water Resources, there is concern for the amount of the physical water supply in 2 periods of prolonged drought, where the spring may not be capable of meeting even the in-house demand. Legal Water Supply: Originally, the existing well was the subject of a West Divide Water Allotment contract, which was amended to include diversions made from the springs. The springs are the subject of a conditional water right decree, wherein the applicant was awarded an amount equivalent to 75 gallons per minute (GPM)1, for each spring. This right is subordinate to an absolute right granted to the BLM (USA) for an equivalent amount of 3.1 GPM, for wildlife watering and habitat. (Although this decree is for Ponderosa Springs #1 and #2, only Spring #2 has been developed and measured.) Obviously, the spring is not flowing at this rate, which underscores the issue associated with the Division of Water Resources' opinion that a call could be placed on the spring and possible curtailment of the water source to the subdivision. Since the BLM has the absolute right, it appears that the Division does not consider the statement made by Roy Smith, BLM Water Rights and Instream Flow Coordinator (wherein the BLM would not place a call on the spring), to be enforceable and suggests a call on the subdivision water supply is possible. A Supplemental Water Supply Report was submitted prior to the Planning Commission review of this subdivision and forwarded to the SEO for its review and additional comment. To, date, the SEO has not provided its written opinion concerning injury to senior water rights and physical adequacy of the supply. Staff has evaluated this supplemental report and, based on this information, it appears that the flow of the spring is sufficient to provide a domestic supply to the subdivision lots. Staff notes that the Subdivision Regulations are silent to an actual, physical supply that is sufficient to serve the needs of a particular subdivision. In staff's opinion, this water supply is marginal and pushes the limit of a physical water supply. However, in staffs experience with Garfield County, a more -detailed physical water supply report, for a subdivision of this size, has never been submitted for review. If the engineer's calculations and assumptions concerning the long-term flow rate from the spring are correct, then an adequate, in-house water supply probably exists. See Report, pages g — Z 5 . C. Soils/Sewer: The method of waste water disposal is the use of ISD systems for the individual lots. According to the Soil Conservation Service, soils on-site are predominantly within the Nihill channery loam classification, typically deep and well - drained soils. When used for community development and the placement of ISD systems, these soils are considered, by the SCS, to have severe constraints. On July 25, 1996, percolation tests were performed, indicating that conventional septic 1 0.1666 cubic feet x 7.48 gallons x 60 sec = 74.7 gallons 1 sec 1 CF 1 min 1 min systems could be utilized. See report, page 2G . Given this information, it is likely that a conventional ISD system could be utilized. D. Access: Access to the lots would be from the historical access point, which would be developed as a shared easement, proposed to be 30 feet wide. Regulations require this 30 foot easement, which may be developed with a single travel lane, 12 feet in width. Flows from an existing drainage gully would be directed through a 36 inch culvert to provide access to the designated building envelope for Lot 1. The State highway department has recently issued a driveway permit that approves access to the proposed lots. Site distances along State Highway 13 are sufficient and staff sees no special problems associated with access, as long as it is constructed in a way that does not impede the historic drainage flows. E. Fire Protection: The Rifle Fire Protection District has responded, suggesting this subdivision would not materially impact the ability of the District to provide services. The District does request that the applicant create defensible space around the dwellings and instructs the applicant to work with neighbors to identify water supplies for fire fighting purposes. See letter, page 2:3 . Staff suggests the inclusion of the standard plat note addressing wildfire mitigation. F. Natural Hazards: According to Exhibit H of the application,' the eastern portion of the subdivision site is identified on a landslide deposit (Qls) and the western portion is identified on an alluvial fan deposit (Qfy). The Colorado Geological Survey has conducted an analysis of the site and strongly recommends that these hazards be evaluated by a qualified professional, and an appropriate building envelope, for Lot #1, be designated on the plat. Pursuant to the CGS written responses, the proposed building envelopes have been further evaluated by the applicant's engineer and geologist. This evaluation has considered the size of the upstream drainage basin, the 100 year flood flow rate and the relative elevation of the proposed building envelope. This study concludes that flood flows in excess of the 100 year flood would not affect the building envelope as it is currently proposed. See letters and information, pages 3 b . The engineering evaluation states that the landslide deposits on proposed Lot #2 are not active and proposes that, if the subdivision is approved, the building envelope be further evaluated, with site specific testing for building permit application. G. Easements: All required easements for access, utilities, water supply, etc.,would be required to be shown on an a final plat. 'Preliminary Geologic Map of the Horse Mountain Quadrangle, Garfield County, Colorado H. School Site Acquisition Fees: The applicant would be required to pay the $200.00 school site acquisition fee, for the creation of the subdivision parcel. V. SUGGESTED FINDINGS 1. That proper publication and public notice and posting were provided as required by law for the hearing before the Planning Commission and the Board of County Commissioners. That the hearings before the Planning Commission and the Board of County Commissioners were extensive and complete, that all pertinent facts, matters and issues were submitted and that all interested parties were heard at the hearing. 3. That the proposed subdivision of land is in general conformity with the recommendations set forth in the Comprehensive Plan for the unincorporated area of the County. 4. That the proposed subdivision of land conforms to the Garfield County Zoning Resolution. 5. That all data, surveys, analyses, studies, plans and designs as are required by the State of Colorado and Garfield County have been submitted and, in addition, have been found to meet the requirements of the Garfield County Subdivision Regulations. VL RECOMMENDATION At its February 11, 1998, session, the Garfield County Planning Commission recommended APPROVAL (7-0) of the Ponderosa Subdivision, subject to the following conditions: 1. That all representations of the applicant, either within the application or stated at the meeting before the Planning Commission, shall be considered conditions of approval. A Final Plat shall be submitted, indicating the legal description of the property, dimension and area of the proposed lots, access to a public right-of-way, and any proposed easements for setbacks, water supply, drainage, irrigation ditches, access, utilities, etc. 3. The applicant shall prepare and submit a Subdivision Improvements Agreement addressing all on-site improvements, prior to the submittal of a final plat. 4. That the applicant shall submit school site acquisition fees, for the creation of the additional subdivision parcel, prior to authorization of a final plat. The applicant shall be notified of the actual fee that will be applicable at time of submittal of the final plat. 5. That the following plat notes shall be included on the final plat: "Pursuant to C.R.S. 30-28-136(h)(I), the State Engineer has found that the water supply for this subdivision will result in the material injury of senior water rights. All prospective future owners are advised to seek a copy of the State Engineer's opinion." "The minimum defensible space distance shall be 30 feet on level terrain, plus appropriate modification to recognize the increased rate of fire spread at sloped sites. The methodology described in "Determining Safety Zone Dimensions, Wildfire Safety Guidelines for Rural Homeowners," (Colorado State Forest Service) shall be used to determine defensible space requirements for the required defensible space within building envelopes in areas exceeding five (5) percent grade." "Soil conditions on the site may require engineered septic systems and will require engineered building foundations based on site-specific soils testing." "The individual lot owners shall be responsible for the control of noxious weeds." 6. That the final plat submittal include a copy of a computer disk of the plat data, formatted for use on the County Assessor's CAD system. That all proposed lots shall comply with the Garfield County Zoning Resolution of 1978, as amended, and any building shall comply with the 1994 Uniform Building Code, as adopted. 8. The water rights associated with the Ponderosa Spring #2, together with the well permit(s), shall be transferred by the developer to a homeowner's association which shall have the power and the duty to enforce compliance by lot owners with the terms and conditions of the well permit. Appropriate Protective Covenants shall further require compliance with the terms and conditions of the well permit. 9. That the following provisions be included in the protective covenants governing the subdivision: One (1) dog will be allowed for each residential unit within this subdivision and the dog shall be required to be confined within the owner's property boundaries. Enforcement provisions shall be developed for allowing the removal of a dog from the area, as a final remedy in worst cases. No open hearth solid -fuel fireplaces will be allowed anywhere within this subdivision. One (1) new solid -fuel burning stove as defined by C.R.S. 25-7-401, et. seq., and the regulations promulgated thereunder, will be allowed in any dwelling unit. All dwelling units will be allowed an unrestricted number of natural gas burning stoves and appliances. All exterior lighting shall be the minimum amount necessary and all exterior lighting shall be directed inward, towards the interior of the subdivision, except that provisions may be made to allow for safety lighting that goes beyond the property boundaries. 4395 1 794-- - \ - --- -- 94- --/o oA'� � �i \ "g890.- \�\ � �. 4394 �Oy 4393 T. 4 5. T. 5 S. 670 000 FEET \`\,� ✓^ Ji�i 77^-7Z-. 7000 4391 �n eV 6.600 39°3730" ;254 255 107°52'30" Mapped, edited, and published by the Geological Survey ja.\y4k Control by USGS and USC&GS xxpb�‘‘ Topography from aerial photographs by multiplex methods " Aerial photographs taken 1948. Field check 1952 Polyconic projection. 1927 North American datum 10,000•foot grid based on Colorado coordinate system, central zone Dashed land lines indicate approximate locations - 1'48• 32 MILS ""mi..— is 11. 340 000 FEET MN I) / 15' 267 MILS "a 0' '257 RIFLE /JUNC U _` OLENWOOD SPRl' g OF THE GARFIELD COUNTY ZONING OF 1978. AS AMENDED: N a d (11 U r- 17/ - U m 0 z A u NW U N m 4J� 1$ 0 2 A a A 2 GIRL 1V3S CNV m X N ym OR n ') / eco` / la �j n // laZi 4* 4. '• Zti�GR Mg W Cf ce re ;T; 'Y atg / ►y /xy UO2 fo 3dO13AN3 ONIQ11118 BASIS OF BEARINGS: SC9'49'00"1I m>v 2 O • D . fig • 2 W C 0 mcz N Z u .g U 0 .D 4 • / _- / n ✓ / sc a t 8 N00'20'53 ,,, , 44 NN Zr�n r September 29, 1997 (QCT 0 1997 ICL OC/J;44TY Jarfk[cf School (District o. e-2 J,nnard (Eckhardt Superintendent *i.,wrence (D. Mc(3ride ,associate Superintendent Garfield County Planning Department 109 8th Street, Suite 303 Glenwood Springs, CO 81601 To Whom It May Concern: The Garfield Re -2 Board of Directors has reviewed the Ponderosa Subdivision preliminary plan request which is going before the planning commission on November 12. Due to the size of the project, there were no concerns or comments. Sincerely, Lennard Eckhardt Superintendent 839 (Whiteriver Avenue, Ct Te, Colorado 81650-3500 1970) 625-7600 .ax 625-7623 BOOK CLIFF SOIL CONSERVATION DISTRICT P.O. BOX 1302 GLENWOOD SPRINGS, CO 81602 October 3, 1997 Eric McCafferty Garfield County Planning Department 109 8th Street, Suite 303 Glenwood Springs, CO 81601 Dear Sir, 1..i � 22 1 •- �+"t twt0'61991H GAFfELQ Cvi1:v"! Y At the regular monthly meeting of the Book Cliff Soil Conservation District, the Board reviewed the application and plan for the The Ponderosa Subdivision and have the following comments and concerns about the project. Any cuts for roads or construction should be revegetated to prevent erosion. Weed free seed and mulch should be used for any reseeding of the area. Monitoring of all seeding should be done to see if the grass is establishing or if weeds are becoming a problem. Reseeding or weed control practices should be implemented if a problem is noticed. The board is always concerned about animal control in an area where there is the potential for conflict between wildlife or domestic livestock and dogs from the subdivision. Dogs running in packs of two or more can maim or kill domestic livestock and wildlife. The District recommends animal control regulations be adopted in the covenants for the subdivision and that they be enforced. Of prime concern to the Board, is the proper maintenance and protection of any irrigation ditch which is on the site. New landowners should be informed that the ditch owners have right of way easement to maintain the irrigation system, that they will be cleaning and working on the ditch, and that this work may be in their yards. The district would like to know what the impact will be on the Wetlands in this area? All Wetlands should be protected and remain in as pristine condition as possible. The Board recommends that any irrigation water rights be used by the landowners so they are maintained. In order to use these rights, a raw water delivery system could be used for landscape, fire protection, open space, etc. If at all possible, this system should be incorporated into the infa-structure of the subdivision plans as it would be more cost efficient at this time. Their concern is always for soil and water conservation and preservation and plans should consider these concerns. Drainage has the potential to be a problem in the area and engineering recommendations for control of drainage should be closely followed by the builder and/or homeowner. They felt that any disturbance of soil could adversely affect other landowners, and great care should be taken to mitigate as many of the problems as possible which arise when building on an alluvial fan deposit area. With increased concerns about Water Quality, the District is concerned about monitoring chemical application for fertilizer, weed control, and other pest management reasons. Their concern is the chemicals that will be used to fertilize grasses and control weeds in the area. They feelthat the chemicals should be closely monitored in this area due to the possibility that the chemicals will soak into the soils and run off into the creeks. The District suggests drilling of wells to monitor ground water pollution, and that this expense and future expenses should be bore by the developer. Sincerely, I Charles Ryden, 1 esident Book Cliff Soil Conservation District STATE OF COLORADO OFFICE OF THE STATE ENGINEER Division of Water Resources Department of Natural Resources 1313 Sherman Street, Room 818 Denver, Colorado 80203 Phone (303) 866-3581 FAX (303) 866-3589 October 27, 1997 Mr. Eric McCafferty Garfield County Building and Planning 109 8th St Ste 303 Glenwood Springs CO 81601 ,cr 0 199 :. ���,�.!' • . Romer `tj N 1 Governor y�.h }� i'r� �•'`' r James S. Lochhead Executive Director Hal D. Simpson State Engineer Re: Ponderosa Subdivision SWI% Sec. 5, T5S, R93W, 6TH PM W. Division 5, W. District 39 Dear Mr.. McCafferty: We have reviewed the above referenced proposal to create two single family lots on a parcel of 8.56 acres. The proposed water supply is to be provided through a shared well and two springs, one of which has been improved. The springs were decreed in consolidated case nos. 95CW11/96CW166. As noted in our previous letter of June 21, 1996, permit no. 46279-F was issued on June 20, 1996, for expansion of use of the existing well with permit no. 185364. Permit no. 46729-F was issued pursuant to a water allotment contract with the West Divide Water Conservancy District, and allows the well to be used for ordinary household purposes inside two single family dwellings, the irrigation of a total of 24,000 square feet of lawns and garden, and the watering of domestic animals. In contrast, the Water Supply Report prepared by Zancanella and Associates indicates that the water supply is not adequate for the proposed uses. The report states that historically the well has experienced shortages in meeting the water requirements of the existing home, and that the improved spring, Ponderosa Spring #2, is not capable of meeting the assumed irrigation demand. Based on data gathered from October of 1996 through August of 1997, the report indicates that Ponderosa Spring # 2 appears more than adequate to meet the in-house demands of the subdivision. However, there is no data to support the conclusion that the water supply will be adequate during drought periods. The decree in consolidated case no. 95CW11/96CW166 also indicates that the applicants uses are junior to the Bureau of Land Management's uses, which means that there is a possibility that the applicant may be called out, with no augmentation plan in place to allow continued diversions without injury to the senior water right. Therefore, pursuant to Section 30-28-136(1)(h)(I), C.R.S., it is our opinion that the proposed water supply will cause material injury to decreed water rights and that the water supply is not adequate to meet requirements of the proposed subdivision. If you or the applicant has any questions concerning this matter, please contact Craig Lis of this office for assistance. Sincerely, Steve Lautenschlager Assistant State Engineer SPL/CML/ponde_sr.doc cc: Orlyn Bell, Division Engineer James Lemon, Water Commissioner, District 38 STATE OF COLOMJJC COLORADO GEOLOGICAL SURVEY Division of Minerals and Geology Department of Natural Resources 1313 Sherman Street, Room 715 Denver, Colorado 80203 Phone (303) 866-2611 FAX (303) 866-2461 October 30, 1997 No7ii DEPARTMENT OF ,NATURAL SOURCES Mr. Eric McCafferty Garfield County Department Building and Planning 109 8th Street, Suite 303 Glenwood Springs, CO 81601 NOV 0 3 1997 ay Romer lOovernor games S. Lochhead ecutive Director - chael B. Long CiotilHELD Gcivision Director �+) ��,N� , , `/ Vicki Cowart State Geologist "fir,, and Director RE: Ponderosa Subdivision Preliminary Plan Land Use Review Dear Mr. McCafferty: At your request and in accordance to Senate Bill 35 (1972) this office has reviewed the materials submitted for this proposed subdivision and conducted a site inspection on October 28, 1997. The property is northwest of Rifle, located on the edge of the steep hills of the Grand Hogback. The Grand Hogback is a monocline where the Mesa Verde Sandstones beds are steeply inclined and form the very steep ridges and flatirons. This office has reviewed the preliminary plan for the subdivision. In that plan are the excerpts from the latest geologic map of the Horse Mountain Quadrangle and the SCS soils report. Within the plan it is stated that `Further geologic investigation is not warranted for this simple two lot subdivision.' It is not appropriate for a lawyer to be making land use judgements concerning geologic hazards. A review of the geologic map insert in the preliminary plan, in fact, shows that the site bridges two different mapped geologic units. Both landslide and alluvial fans terrains are potentially hazardous and can create problems for residential land usage. A large portion of Lot #2 lies within the landslide complex. While the location of the existing trailer home is acceptable, as is most of the southwest portion of the lot, we do not recommend acceptance of the building envelope as shown on the preliminary map plan. The entire portion of the lot #2 north of the power line easement, and the eastern margin, lie within the mapped landslide and should be excluded from approved building envelopes within the lot. Lot #1 lies entirely on an alluvial fan. Alluvial fans are created by sediments that are transported by water. The bulk of the sediment is deposited during debris flow storm events. The fan shape is the result of the channel constantly moving. They wander over the entire fan because debris flows have the ability to bridge, or plug off, established channels and create new ones. In our field inspection we verified that the drainage that divides the two lots comes from a small basin that only extends to the rock face of the flatirons. That basin is several feet lower than the elevation of the main drainage where it exits the ridgeline onto the fan. There is only about a two foot saddle of earth that prevents the lower basin from capturing the main drainage and directing this much larger flow towards the two lots. Another potential hazard that can result from alluvial fans are hydrocompactive soils. These soils have the property where they compress, or settle, when they become wetted. This type of settlement can create serious problems with shallow foundations and slab on grades. Our recommendation to the county is that they not grant approval for this land use until the landowner provides them with a professional engineering geologist's analysis, opinions, and recommendations on the hazards mentioned above. We recommend that the County resubmit this additional data to the CGS for our review. If you have any questions please contact this office at (303) 894-2167. Sincerely, ur+ Jonathan L. White Engineering Geologist P.O. Box 1908 1005 Cooper Ave. Glenwood Springs, CO 81602 Z4NC4NELL4 4N0 455OCI4TES, INC. ENGINEERING CONSuLVaNTS December 10, 1997 Mr. Eric McCafferty Garfield County Planning Dept. 109 - 8th Street, Suite 303 Glenwood Springs, CO 81601 (970) 945-5700 (970) 945-1253 Fax k DEC 'i u 1997. cloviF=LD l:t.duN iY �r RE: Ponderosa Subdivision - Supplemental Water Supply Investigations Dear Eric: Zancanella & Associates, Inc. has conducted additional investigations into the water supply of the Ponderosa Subdivision being proposed by Mr. Kenneth Rose. We have prepared this letter to summarize additional work which has been completed and to highlight the issues surrounding the proposed water supply. This letter should be considered supplemental to our letter dated August 19, 1997. As stated in our earlier letter, and supported by additional research and developments, we believe the proposed water supply will provide an adequate water supply to serve the in-house needs of the two lot subdivision. Background History As you may recall, the demands for the development were based on in-house uses only for two single family residences (one unit per lot). Each house was estimated to have 3.5 people each using 100 gallons per day for a total of 350 gallons per day per house, or 700 gallons per day for the development. We believe this estimate to be slightly conservative and provides a good planning estimate. We have seen water estimates used by others of 80 gallons per person per day. We believe the lower use estimates are justifiable for homes with low water use fixtures and appliances. The existing home at the site, which utilizes such fixtures, has averaged approximately 70 gallons per day diverted from Ponderosa Spring No. 2 since a meter was installed last July. The supply of irrigation water is not a project goal of the developer and should be considered a supplemental demand. We have previously recommended that a note on the subdivision plat be required noting the irrigation supply is supplemental to the in-house demands of the development. The Rose water rights include irrigation uses. The water supply for the development consists of a well and the Ponderosa Spring Nos. 1 and 2. The well is not currently used at the existing home. The springs are located on the adjacent Bureau of Land Management (BLM) property at the base of the Grand Hogback. The Ponderosa Spring No. 2 was developed in February of 1997 and currently serves the existing home. Page -1- The spring can be visually observed exiting an scarp on the hillside. The flows exit the scarp and pass through a vegetated area approximately 15 feet in length prior to entering an infiltration gallery with a spring collection box. The Ponderosa Spring No.2 spring box installed by Mr. Rose is elevated on washed rock material which allows for a bypass flow to a lower elevation drain pipe which collects portions of the uncaptured spring flows and delivers it to a small watering area (5 -foot diameter by 1 -foot deep pond). It should be noted that the spring development is not situated on top of formation and additional uncaptured spring flows exist below the Rose improvements. The small watering area was constructed with a impermeable liner and then covered with native rock material. The watering area was developed by Mr. Rose to supply a bypass flow for wildlife watering water rights developed by the BLM. The BLM water rights for the spring were adjudicated junior to Mr. Roses rights in the Ponderosa Springs. However, in consolidated Case Nos. 95CW111 and 96CW166 the decree remarks that the Rose rights are to be administered junior to the BLM rights as per a stipulation attached to the decree. Investigation of the physical supplies available from the Ponderosa Spring No.2 were undertaken with a field visit and implementation of a spring monitoring program in October of 1996. The geologic formation that the spring exits appears to be comprised of a low permeable cemented material. The spring has created a small gully located on the hillside below the base of the Hogback. Minimal vegetation and water pooling was observed at the original spring. Vegetation or flows were undetectable approximately 70 feet below its discharge where it appeared all of the springs flow had percolated back into the earth. Prior to the spring development, the spring flows were measured to be 959 gallons per day. Measurements taken the following February and May indicated that the spring flows maintained at a fairly consistent level. The measured flows did not include the flows being bypassed to the BLM. A summary of spring flow data is presented in the following Table 1. Table 1 Ponderosa Spring #2 - Flow Measurem Dat®F F .a �� 4 Flow'{gal/min), . Flow (gal/day) October 17, 1996 11 0.66 959 February 15, 1997 0.75 1,080 May 15, 1997 0.65 936 June 14, 1997 0.83 1,195 August 10, 1997 0.81 1,166 September 15,1997 0.87 1,252 October 19, 1997 1.08 1,555 November 15, 1997 1.09 1,570 „Measured prior to spring development. Based on the installation of the existing storage tanks, it was our opinion that the single spring would serve the needs for the two lot development. However, the production of the Page -2- spring during a severe drought period was unknown due to the lack of observations during such a period. It was our opinion, that based on the consistent flows measured over the winter of 1996 and 1997, the aquifer exhibited characteristics that it had the ability to store inflow and make releases at steady levels. In other words, the groundwater aquifer characteristics which prevents this spring from experiencing high "gushing" discharges fluctuating through time during varying precipitation events, supports its ability to provide continued supply during dry periods. In the event that reduced spring flows occurred during a drought period it was assumed that the Ponderosa Spring No.1 could be developed to enhance the supply. Review of the proposed water supply by the Colorado Division of Water Resources was completed by Steve Lautenschlager and summarized in a letter dated October 27,1997. It was the state's opinion that the proposed water supply plan would cause injury to the BLM's rights at the spring and was not adequate to meet the requirements of the proposed subdivision. The concern over the BLM injury is based on the BLM's instantaneous diversion amount of 0.007 cfs (3.1 gallons per minute) which was stipulated to be senior in priority to the Rose rights. This amount is obviously greater than the observed flows at the spring and theoretically could require the Rose rights to bypass all flows to the BLM. We believe that a potential call from the BLM is unrealistic due to the location and decreed use of the BLM rights. In order for the BLM to place a call on the rights it would require beneficial use of the spring flows. We believe a call by the BLM for the entire spring flows would result in water percolating back into the ground below any watering areas. Any water called and not being used to meet the decreed wildlife uses would thus be considered wasteful which could nullify the call. Additionally, the lack of any constructed diversion facilities by the BLM and the inability to measure uncaptured spring flows raises doubts as to wether a call could be enforced. It is our understanding that the BLM requested the senior status to the Rose rights to insure the existing vegetation was not dried up and enough flows were available to meet wildlife watering demands. Based on improvements to the spring which and the addition of the bypass/watering area, we believe the BLM was satisfied with the water split at the spring. This is evidenced by the letter prepared by Roy Smith of the BLM who indicated the developments by Mr. Rose were adequate for the BLM uses and would not be subject to a call. To further define the BLM's position, a subsequent agreement (attached) was approved by the BLM which quantified the volume of water which could be called. The volume amount was determined based on a measurement of the bypass flow at the spring. Based on the agreement with the BLM and other issues pertaining to the administration of these rights, which will be discussed later in this letter, we do not believe a call will be placed by the BLM or be administered against the Rose rights as long as the current bypass flows are maintained. It has been our experience that the state typically does not require proof of the dry year or "drought" yield of groundwater supply's. Such estimates are difficult to examine due to the various unknown physical characteristics associated with the aquifer combined with the Page -3- _ /5J unknown recharge amounts (typically precipitation). Nonetheless, due to the relatively small discharge flows of the spring, additional investigations are warranted to better understand the potential future flow production rates. Our investigations into the reliability of the spring have been focused on examining the recent spring flows and precipitation events and comparing them to historic precipitation records and streamflow conditions in the area of the spring. Additionally, we believe the reliability of the spring is best supported by historic accounts of similar spring users near the proposed subdivision. Physical Water Supply The hydrologic cycle is a complex process which has many factors which determine the amount of precipitation that is converted to either surface runoff or groundwater recharge. A detailed groundwater study of the subject aquifer is not feasible and still would require numerous assumptions to estimate future spring production rates. However, we can examine past precipitation data to gauge the relative impact of historic drought conditions in the area of the spring. Although the comparison of historic precipitation data can not tell us directly what the future flows will be, it can act as a barometer to the severity of historic drought conditions as compared against average conditions. The Ponderosa Subdivision is located at the base of the Grand Hogback several miles north of Rifle. The estimated average annual precipitation at the site is approximately 15 to 16 inches per year based on isoheytal maps prepared by the Colorado Climate Center. National Weather Service cooperative weather stations have recorded historic precipitation records in this area for the locations of Grand Junction, Rifle, Meeker, Glenwood Springs, and the Altenbern Ranch near Debeque. The closest weather station would be the City of Rifle. Examination of historic precipitation data for the Rifle station indicates the long term annual average is approximately 11.6 inches per year. The attached Table 2 summarizes the available monthly and annual precipitation amounts recorded at the Rifle station for the periods of 1940 to 1996. The following Table 3 summarizes the long term average annual precipitation values for the other weather stations. Table 3 - Average Annual Precipitation (inches) Station Grand Jct Rifle Meeker Glnwd Spgs Altenbern Precip. 8.9 11.6 13.3 16.7 16.9 As can be seen in Table 2, the precipitation values range from a low at Grand Junction of approximately 8.9 inches per year to a high at Altenbern of 16.7 inches per year. The lowest annual recorded precipitation at the Rifle station for a complete year occurred in 1962 and totaled 8.0 inches. It is interesting to note that although we believe Rifle could be classified as an area below the state average precipitation, the relative difference between its average precipitation and its driest record period is not extreme (approximately 69% or 8.0/11.6). The attached Table 4 summarizes recent monthly precipitation data for the above stations. The Rifle station was discontinued in July of 1996 to August of 1997. During this period Page -4- we have estimated the monthly precipitation amounts for Rifle by averaging the other station monthly totals prorated by the ratio of the stations long term averages. The precipitation data for the year prior to the initial spring flow measurements totaled 11.3 inches and can be considered average. We believe the spring flows observed during the winter of 1996 to 1997 were average discharge levels experienced under average precipitation conditions. Therefore, average flows from the spring are approximately 1,000 gallons per day. Assuming the dry year production of the spring is reduced by the same ratio as the dry year versus average year precipitation levels, then the dry year flow of Spring No.2 would be approximately 690 gallons per day (1,000 gallons/day * 69%). Available streamflow records were examined for a gaging station maintained on Rifle Creek for the period of 1939 to 1964. Unit runoff values were determined for the winter periods which we believe more accurately represents groundwater flow contributions versus surface runoff. The average unit runoff during this period was calculated to be 0.51 inches. The driest or drought year value was recorded in 1954 and was approximately 0.27 inches. Although the runoff characteristics of a large stream can not be correlated directly to the spring flows, the ratio of the average versus driest year records aids as an additional tool to show extreme conditions. Based on the extreme streamflow ratio of 50% (0.27/0.51), and assuming the spring were to experience similar characteristics, the Rose dry year flows would average approximately 500 gallons per day from the Ponderosa Spring No. 2. We believe that if the spring were to drop to these levels, then the Ponderosa Spring No. 1 would have to be developed to meet the full 700 gallons per day demands. The flow production of the Spring No. 1 has been previously estimated by Rose and the BLM to be equivalent to the Flows of Spring No. 2. Conservatively assuming that the Spring No. 1 flows were 50% of Spring No. 2, then the combined supply would be sufficient to meet the in-house demands of the development. We do not believe the development of the second spring will be required. The above Table 1 shows that spring flows have steadily increased during the past 6 months of monitoring. The increased spring flows can be correlated with above average rainfall rates during the last 8 months which have totaled approximately 14.5 inches. Review of the Division of Water Resources 1996 water rights tabulation indicates that multiple spring rights have been adjudicated along the base of the Hogback near the subject site. We believe there is a confining layer at the base of the Hogback which forces the groundwater to the surface. The nearest water right is the Corlett Spring located at the next residence below Rose's property along Highway 13. The approximate spring location is shown on Figure No. 1. Decreed conditional in 1980 for 0.018 cfs (8.0 gpm), this right has been made absolute for only 0.0033 cfs (1.5 gpm) which is approximately equal to the magnitude of the total flow production from the Ponderosa Spring No. 2. The Corlett Spring was developed by Mr. "Buzz" Corlett who has lived and worked in the area along the Hogback for over 50 years. Mr. Corlett indicated that his spring, along with multiple other springs which he has developed for other individuals along the Hogback do not fluctuate seasonally or annually. Mr. Corlett also indicated that his spring has always been adequate to serve his residence and that he has never seen any of the springs along the Hogback dry up. These include springs developed by other domestic users as well as BLM Page -5- l9 springs he has observed while hiking or hunting. Mr. Corlett was very cooperative in our discussions and indicated the willingness to discuss the history of this area as may be required in the future. Water Rights Administration The Rose and BLM spring water rights are only administered amongst each other with no water rights uphill from the spring. Although water rights below the spring exist on Government Creek, we do not believe they materially contribute to the Government Creek surface flows and could be administered as a futile call. This position was recognized by the District 39 water commissioner. Based on the current development of the spring and the agreement with the BLM, we do not believe the spring flows diverted by Rose could be called out by the BLM rights. Even without the current agreement, the BLM would have to demonstrate beneficial uses of any additional called water. Wildlife water use demands are not a typical demand estimate that we have examined in the past and is therefore difficult to quantify. However, for discussion purposes we can estimate the ability of the spring to provide water demands for deer which we believe would pose the largest demand potential for this area. The daily consumption requirement of a deer is approximately 4.6 gallons per day. This is based on water use requirements for livestock (15 gpd) prorated by the daily forage requirements between the two animals. The current bypass of water is approximately 176 gallons per day. The current bypass flows could therefore supply the water needs of approximately 38 deer daily. This high demand is improbable based on wildlife observations in this area. We believe the BLM demand will be satisfied by the current bypass which will also be served by the lowest level of water produced from the spring. Additional calls by the BLM are unrealistic. We believe this opinion is supported by the cooperative efforts which have been demonstrated by the BLM with regard to this issue. Recent discussions with the Division of Water Resources have indicated that the state may not administratively recognize the agreement between the two parties. This position is based on a policy of not recognizing "selective calls". Our understanding of the definition of the selective call is that a senior water right can't selectively not place a call against one or more junior rights while still placing a calls against other junior rights. We agree with this policy which we believe equally protects all water rights. However, we do not feel that it is applicable to the spring because there are no other water rights administered in connection with the spring (i.e. no upstream rights and futile call downstream). Furthermore, if the state were to strictly enforce this administration policy and not recognize the agreement, then we believe that the state would not be able to enforce the stipulation agreement of the water rights in the decree. This is because the stipulation essentially allows the senior rights of Rose in the spring not to place a call against the junior water rights of the BLM. Or in other words the stipulation with the subordination of the Rose rights to the BLM fits the definition of a selective call. Summary The following comments summarize our opinion of the proposed water supply. 1. The current physical water supply produced from Ponderosa Spring No. 2 is sufficient to meet the in-house demands of the proposed development. It is not the goal of the developer or the water supply to provide a reliable yield for irrigation uses. The plat should note the priority of in-house water uses over irrigation use. 2. The aquifer supplying the spring has shown characteristics that it has the ability to detain inflow (precipitation) and produce steady flows. The low transmissivity of the aquifer will therefore will still produce flows even during or following periods of dry or "drought" conditions. The aquifer properties are supported by the consistent flows observed at the spring through the first winter of observations followed by a moderate increase of flows during a period in which the precipitation is above average. 3. The spring flows observed during initial monitoring stages are assumed to be average conditions based on the average amount of precipitation which occurred during the previous year. The average spring flow available to the Rose rights at the Ponderosa Spring No. 2 are 1,000 gallons per day. Demands of the development have been conservatively estimated to be 700 gallons per day. 4. Average annual precipitation recorded at the Rifle weather station is 11.6 inches per year. The lowest year of precipitation over the last 57 years has been 8.0 inches. We believe the ratio between these values (69%) is not extreme. The Rifle area appears to be below average and therefore the ratio to the drought condition is not as drastic as might be compared for other areas in the state where the average precipitation values are higher. Assuming this ratio correlates to the same percentage of reduced spring flows, then the single spring could still meet the development's demands. 5. Streamflow records for Rifle Creek have indicated that the single winter season lowest streamflow amount was approximately 50% of average streamflow conditions. Assuming similar conditions developed for the spring , then 500 gallons per day would be available from Spring No. 2. If such an event were to occur, either the Spring No. 1 could be developed to meet the full demands or water conservation measures could be implemented by the development for the drought conditions. Due to the relative small size of the development we do not believe the development of Ponderosa Spring No. 1 is warranted at this time. 6. The best indicator of future production rates of the spring can be based on the production of similar type springs located near the proposed subdivision. Multiple water rights have been developed along the base of the Hogback with similar geographic locations as the subject springs. The nearest spring was decreed by Buzz Corlett who has indicated that his spring has not fluctuated through time and Page -7- -2-/- has always provided a reliable supply to his residence. Mr. Corlett has also developed springs for others in this area as well as observed non developed springs which have all maintained flows even during dry years. We believe the Corlett spring is very similar to the Ponderosa Spring based on geographic locations and observed flow rates. 7 The development of the spring allows a physical bypass of water to the BLM for wildlife watering. The bypass flows were measured to be 176 gallons per day. Any reductions in spring flows will occur to the Rose diversions with the lower level BLM flows maintained. 8. BLM has acknowledged the spring improvements completed by Mr. Rose and has subsequently offered cooperation to demonstrate their intention of not placing a call on the Rose rights. The BLM's cooperation has been demonstrated by a letter submittal and agreement from the BLM's water rights coordinator. The agreement requires Rose to provide 160 gallons per day of bypass flow. 9. Additional BLM calls above the current bypass requirements are unrealistic due to the lack of demands which we believe could be claimed. This assumes that a call from the BLM would have to be consumed otherwise the water not utilized could be considered wasteful. The administerability of a BLM call is questionable to the lack of any diversion structures, measuring devices, and uncaptured spring flows. 10. We believe the water split agreement with the BLM can be administratively operated due to the lack of any calling upstream or downstream rights. If the policy of a no "selective calls" is enforced by the Division of Water Resources, then we believe the state would also have to not enforce the selective call nature of the existing decreed stipulation. If you have any questions, please call our office at (970) 945-5700. Very truly yours, Zancanella & Associates, Inc. e Christopher Manera, P.E. Encl cc: John Savage Kenneth Scott Rose \\Gateway 48650\f\96339\Mcferty2.wpd Page -8- -22-. Station - 57031 Table 2 Monthly Climatic Data for RIFLE for years 1940 - 1996 Latitude - 3931 Longitude - 10747 Elevation - 5300 Total month 411 1281 7 1991 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 11.4 1992 19 61 112 30 229 75 213 60 146 161 97 64 1940 162 128 94 144 40 23 86 169 206 172 86 110 14.2 1941 92 75 191 150 82 126 43 104 158 311 112 75 15.2 1942 47 100 84 141 35 20 127 43 57 126 55 20 8.6 1943 99 42 146 23 178 150 39 253 53 131 16 76 12.1 1944 182 65 75 116 30 66 99 29 7 45 203 25 9.4 1945 36 114 131 112 122 140 75 65 32 97 88 66 10.8 1946 24 24 60 276 173 65 65 225 51 291 123 93 14.7 1947 61 56 97 105 66 160 125 98 71 144 56 63 11.0 1948 94 143 174 68 9 138 87 112 42 90 79 163 12.0 1949 120 22 152 65 29 80 109 109 131 60 21 64 9.6 1950 186 48 36 56 42 2 163 25 117 21 67 111 8.7 1951 145 48 21 115 69 103 47 156 44 117 64 406 13.4 1952 105 25 180 16 78 64 56 226 6 0 53 42 8.5 1953 64 19 116 127 173 65 117 208 31 148 143 35 12.5 1954 87 29 86 93 76 155 150 194 232 146 152 57 14.6 1955 94 98 20 47 171 54 78 139 15 56 169 72 10.1 1956 131 131 20 127 9 12 154 85 0 85 49 82 8.9 1957 275 91 116 129 279 210 136 418 16 334 139 77 22.2 1958 25 101 102 62 31 24 77 22 151 29 53 M 6.8 M 1959 62 154 40 167 42 . 97 10 240 153 172 7 78 12.2 1960 67 126 119 62 53 20 2 55 51 52 61 58 7.3 1961 1 55 114 92 101 7 26 115 287 108 65 70 10.4 1962 104 219 17 97 51 16 23 12 69 89 52 47 8.0 1963 61 28 63 37 2 78 23 155 1151 151 78 40 8.3 1964 65 14 72 82 140 116 50 101 96 3 105 110 9.5 1965 67 52 128 60 43 110 203 36 231 52 104 58 11.4 1966 53 37 12 45 111 10 24 47 45 172 39 241 8.4 1967 54 34 41 50 161 224 184 107 135 43 57 229 13.2 1968 32 213 39 118 61 9 53 164 21 119 93 121 10.4 1969 264 111 22 48 21 252 31 143 166 363 69 41 15.3 1970 62 20 131 97 2 190 174 77 178 158 176 89 13.5 1971 98 35 42 94 110 T 61 91 157 179 74 188 11.3 1972 15 5 16 79 109 66 71 60 197 344 96 221 12.8 1973 75 53 95 59 71 163 112 216 38 41 81 65 10.7 1974 148 52 76 81 T 60 98 89 46 87 65 126 9.3 1975 84 111 146 80 108 102 42 10 25 61 61 94 9.2 1976 52 181 145 89 158 110 29 113 148 22 T 2 10.5 1977 76 21 48 46 60 12 46 233 112 95 67 111 9.3 1978 235 92 265 116 70 57 21 70 47 23 157 325 14.8 1979 167 92 147 40 322 61 39 92 7 74 123 19 11.8 1980 M M M 103 211 21 M 144 36 M 63 59 6.4 M 1981 52 33 78 39 283 104 224 145 36 294 73 127 14.9 1982 M M 126 8 M 55 47 72 293 122 156 32 9.1 M 1983 40 72 104 258 233 323 190 154 40 103 239 247 20.0 1984 34 8 120 194 105 371 189 260 168 226 M 286 19.6 M 1985 108 78 304 260 155 45 241 30 146 323 359 127 21.8 1986 45 109 78 223 128 21 128 144 330 156 104 30 15.0 1987 78 90 84 70 97 61 103 108 28 96 74 122 10.1 1988 157 47 45 111 56 109 80 71 259 14 181 100 12.3 1989 82 158 47 61 31 20 263 67 77 117 24 10 9.6 411 1281 7 1991 117 28 129 74 31 65 86 99 173 197 90 50 11.4 1992 19 61 112 30 229 75 213 60 146 161 97 64 12.7 1993 15311 240 155 100 155 I 29 87 q 64 1 114 1 111 1 64 1 10.3 M 1994 13 111 ; 25 i 168 211 M4 2 66 138 ! 92 149 M 7.6 M 1995 33 111 95 88 239 881 204 37 1431 81 27 M 10.6 M 1996 136 245 36 1061 46 51 16.2 M Avg 0.84 0.80 1 0.92 i 0.99 0.98 0.85 0.94 1.14 1.05 1.26 0.931 0.96 11.7 M= Missing data/incomplete records 12/09/97 05:46 PM -13 RIFLEPCP WK4 Table 4 Monthly Precipitation - inches Long term Avg 16.73 16.52 8.88 13.33 11.6 Rifle ratio to Avg 0.69 0.70 1.31 0.87 Oct95 to Sep96 Apr97 to Nov97 11.3 Est 14.4 Est Est = Estimated Rifle station precipitation based on average of other monthly station readings and ratio of long time station averages 12/10/97 02:31 PM PRECIP.WK4 Glenwood Springs Altenbern (Debeque) Grand Jct Meeker Rifle Jan -95 1.51 1.17 0.52 1.00 0.33 Feb -95 2.54 1.50 0.26 0.89 1.11 Mar -95 1.67 1.93 1.76 1.14 0.95 Apr -95 1.81 1.42 0.91 3.44 0.88 May -95 5.83 4.15 2.53 5.59 2.39 Jun -95 1.90 1.78 1.29 1.49 0.88 Jul -95 2.03 2.22 0.91 1.13 2.04 Aug -95 0.88 2.66 0.43 1.06 0.37 Sep -95 1.80 2.57 0.98 2.91 1.43 Oct -95 1.15 0.62 0.19 1.41 0.81 Nov -95 2.55 0.64 0.17 1.49 0.27 Dec -95 2.81 0.84 0.32 0.41 0.87 Jan -96 4.44 1.55 0.36 1.95 1.36 Feb -96 2.72 3.45 1.21 2.17 2.45 Mar -96 0.67 0.86 0.39 1.14 0.36 Apr -96 1.96 1.84 0.93 1.90 1.06 May -96 1.21 1.02 0.84 1.18 0.46 Jun -96 0.74 1.64 0.63 1.03 0.51 Jul -96 1.18 1.77 0.70 2.03 1.19 Est Aug -96 0.30 0.46 0.02 0.53 0.25 Est Sep -96 2.92 2.16 1.29 1.75 1.69 Est Oct -96 2.33 2.76 1.11 2.68 1.83 Est Nov -96 1.60 2.32 1.00 2.63 1.58 Est Dec -96 2.52 1.29 0.37 1.32 1.07 Est Jan -97 3.84 2.60 0.31 1.66 1.58 Est Feb -97 0.40 0.49 0.13 0.89 0.39 Est Mar -97 0.77 0.21 0.42 0.45 0.41 Est Apr -97 1.83 2.80 2.55 3.77 2.46 Est May -97 2.36 2.29 1.54 1.87 1.72 Est Jun -97 1.32 0.56 0.42 0.89 0.66 Est Jul -97 1.77 0.72 2.08 2.47 1.65 Est Aug -97 1.67 2.39 1.83 3.29 2.02 Est Sep -97 4.20 5.09 3.38 5.50 3.21 Oct -97 1.69 Nov -97 0.99 Long term Avg 16.73 16.52 8.88 13.33 11.6 Rifle ratio to Avg 0.69 0.70 1.31 0.87 Oct95 to Sep96 Apr97 to Nov97 11.3 Est 14.4 Est Est = Estimated Rifle station precipitation based on average of other monthly station readings and ratio of long time station averages 12/10/97 02:31 PM PRECIP.WK4 1.)(--lab-9( F R 1 1 1 : 1 JOHN W SAVAGE 7 (0610303 r• eJ SUPPLEMENT TO LETTER AGREEMENT OF MAY 29, 1997 Reference: CO -932; 7250 Re: Ponderosa Springs; Div. 5: 95CW111/96CW166 The United States Department of the Interior, Bureau of Land Management, by its undersigned agent, agrees to the following terms to supplement the above referenced Letter Agreement: BLM agrees that its senior water rights in the above refer - o. f 0, Q_Q7__cfS . are_being satisfied by the current construction and administration and further that as long as the existing wetlands upstream to Kenneth Rose's diversion structure are not interfered with and at least 160 gallons per day are al- lowed to flow to the tank/pond below the Rose diversion struc- ture, BLM agrees not to request an administrative call on the ju- nior water rights of Kenneth Scott Rose. BLM expects to be able to enter into a similar agreement as regards the seco d undeveloped spring, assuming similar diversion and s. rage str tures are constructed. Gq y .. `222 _ Date: Ve'ee#16_rl <9T Roy / Smith, water Rights and Instream Flow Coordinator Colorado State Office, Bureau of Land Management 2850 Youngfield St., Lakewood, CO 80215-7076 SOPRIS ENGINEERING • LLC CIVIL CONSULTANTS Kenneth S. Rose 10286 Highway 13 Rifle, CO 81650 November 11, 1996 RE. Ponderosa Subdivision, Sopris Engineering Project No. 96014.01 Dear Mr. Rose: A percolation test was done on-site at the location of the proposed septic field. The test was performed per Garfield County standards as required to determine the soil percolation rate. A profile hole of approximately eight feet in depth was dug and six inches to one foot of topsoil was encountered. The remaining soil was uniform in type and gradation. The test was performed on July 25, 1996 and the percolation rate was determined to be one inch in 35 minutes for hole #1, one inch in 27 minutes for hole #2 and 46 minutes for hole #3. The average is 37 minutes for one inch of percolation. The percolation rate was very uniform for the three holes and falls close to the middle of the required rate for a standard septic system. A standard septic system will be adequate for the on-site soils as long as the septic system is sized for the home. If you have any questions or need additional information, please let me know. Sincerely, Sopris Engineering, LLC Yancv Nichol, P.E. Project Engineer 1101 VILLAOc ROAD, surrQ UL -aa • CdnaCr.iw►cs, CO 81623 • 970-704-0311 • FAX: 970-704.0313 FEB -05-98 THU 11:36 JOHN W SAVAGE Feb -19-97 06:33P Kenneth S. Rose 9706250803 970 625 4454 RIFLE FIRE PROTECTION DISTRICT Ken Rose 10286 Highway 13 Rifle, Colorado 81650 April 16, 1996 Re: Subdivision Mr. Rose. As per our discussion on April 12, the Rifle Fire Protection District has reviewed your proposed subdivision of the property located at 10286 Highway 13. As we had discussed, your intentions are to take the property and split it into two parcels of approximately equal size. The intentions for the new piece of property are to put one single family dwelling on the parcel. This action does not make any significant impacts on fire protection requirements of the District. The main concern, as we had discussed, is that a defensible space should be created around the structure to help and protect it in the event of a wild land fire. Obviously, though not required, I would encourage you to work with the Fire District and your neighbors to identify potential water supplies for any fire suppression activities which may arise in the future. The Rifle Fire Protection District finds that this proposal complies with the current standards adopted by the District. Thank you for your cooperation and feel free to contact me if I can be of further assistance. Sincerely, Mike Morgan Fire Marshal Rifle Fire Protection District Telephone (970) 625-1243 • Fax (970) 625-2963 1850 Railroad Avenue • P.O. Box 1133 • Rifle, Colorado 81650 P.02 P.02 P.O. Box 1908 1005 Cooper Ave. Glenwood Springs, CO 81602 /K\ ZANC4NEaL4 ANA ASSOCIATES, INC. ENCINEESING CONSULTANTS (970) 945-5700 (970) 945-1253 Fax • January 8, 1998 Mr. Eric McCafferty Garfield County Building & Planning Dept. 109 8`h Street Suite 303 Glenwood Springs, CO 81601 Re: Ponderosa Subdivision- Geologic Investigations Dear Eric: We have prepared this letter to address two concerns raised by the Colorado Geological Survey (CGS) pertaining to the above referenced project. Debris Flow Flooding - Currently the majority of runoff near the subject site flows towards and crosses Highway 13 at a point northwest of the proposed subdivision. The CGS has identified a critical channel reach above the property which is at risk of redirecting flood runoff and debris flows towards the existing channel which currently runs through the proposed Lot 1 of the subdivision This channel currently serves a minor basin area above the subdivision. Assuming a large flood event (100 yr+) would be redirected to the existing channel on Lot 1 from the larger basin to the northwest, we have further limited the building envelopes on the two lots to offer additional protection for habitable structures. The recommended building envelopes are identified on the attached Figure 1. The proposed building envelopes are located at least 4 feet above the existing channel. The capacity of the channel at this depth is approximately 1,500 cubic feet per second (cfs). The 100 year flood flow rate was conservatively estimated to be 450 cfs. The 100 year f,ccd was calculated using procedures outlined. in the Soil Conservation Service Technical Release 55 and takes into account the steep rocky terrain of the Hogback area. The tributary area for the flood was measured to be 245 acres (0.38 sq mi) and assumes the all up gradient lands have flows redirected to the subject channel. The existing channel has enough capacity to carry flows significantly greater than the 100 year flood for all of the potential contributing up gradient basin. Landslide Deposits lot 2 - We do not believe the landslide is active. We recommend that site specific soil test be conducted at any future proposed house site. To expend funds on soil test at general locations is not prudent at this time. Page -1- If you have any questions, please call our office at (970) 945-5700. Very truly yours, Zancanella & Associates, Inc. cji4;2/4_ Christo he p Manera, P.E. —1-TA.at-4-‘13-41/4 -A- .o..r.A...ice.4"dit‘. Thomas A. Zancanella, P.E. President cc: Kenneth Rose John Savage \\Gateway 48650\t\96339\Mcferty4.wpd Page -2- • .r, . PRELIMINApY PLAT:: PONDEROSA ,S` UBDI VI `101V A PORTION OF. THE .SW1/4 SW1/4 OF SECTION 5, TOWNSHIP .5 SOUTH, RANGE 93 WEST OF THE SIXTH PRINCIPAL MERIDIAN GARFIELD COUNTY, COLORADO r.0:a -? Zrw T/ �'.c rant a accum.0 rCU:Q a•v .UA A uLomat C.P. C1J :713 4-"/A • - IZ7_31 6°'1,0 I Q `4 tP: C gal. • g:. 1. 7. °° s IIII - RevLse.ot 614 Pa SIS Or. B=.IPINGS: S.?9'49'CG^1f \ Er vek PGs 1/c .• l\ - \ , 122.1.11' I 1 s: -4,-„._________:::-.-„. 13'<�_~�:.'i �'_a 7?i� ��-�� \�.i, e! , , �•r J.^0.`• .... _ _. . „.„..........,....„, 1 il v.ii.1 /-.../.... _ Imo" ..„...„.,.,.,....„...,,.. LG, 1 g. it t /^ _ � ` :.,- .7.0d IC In •....„,./7:- .N., j \ .,`� ..I • - ` L: -- J \ N. . b \ • / • CC \ 7. ▪ . ...•\ \ ` CS:k•C.�CT•_ rC•�G 5yy5(I-. y CC.: VIt . \ ▪ Y • • 00,C ..RO:a p -/ • Lccanot aaalc I I01• TO NC *EST LIN( 1 TC74.4r 1 I197 10 W TU7M L1.LUS:':n: Lacst( Draln��_ ix:. S• . .� �• a-Cr� _, l'C. :: R sR,<-C2 - C-.1.27. OC rtat3r C.,.7.71, IC C::Ka%C S TO : ,S Sc:_'rsr= c MIS r• -•r ,ac tar_ ..0 C• .. cr ^,C:..ir,••CZS CT a!CCa.3 ,.p ra -c ,• ;i r _is:..r n,r. c:a.r3,..rr.. Dr: -t a..r Dm/ ^ !C• /C1...,.C..1 Cr Ix•. eaanrs CCU,rn C.- . S.:r:..,. Cr: r r.rr,2. Mr:. -.r.: 1 Au a acc:roc WO , Qc_.:t: t.c. %•L L.tws ci sq i..r. d CZCax7. rw • a , a - L. �aAC_" ,..o Cvan µ1r Cr n•C ....fir...•: r .f y,: QIr. ►µria. rr:URD O ^..Cw.r MLt2Cn, ]..r G‘.. .:.. •.:: tau ,C.:R.Z w .< 3. •t Cr NC t:r, SY/3 14CP•Ltrr MY Ire ,.r0 C_:... .r :.Cr, ryL LC:.-rj. ,.p ,'tl-r •,i t.•<r1 wv.tar u.p 172U.71 rC Cr :wa yau.rsGv ,&,,,,,t -...C G. M :S r •.J 1 1•.M :Zr YT 4t. , J. is___,..0 Amp Sµ t1r• 7.r C► l LCT 2 ..:. = Lc . 3 Jl d:J ; i re cr. CL':?1C 1a- a+a \ / \ ^1t1r .w IN \ L:. 'C.l l' a - OAS! cr :r.7- • • 1 ADDENDUM TO: Planning Commission FROM: Eric McCafferty SUBJECT: Ponderosa Subdivision DATE: 4 February, 1998 The Commission will recall that the necessity of continuing this application was to enable the applicant sufficient time to conduct additional engineering studies concerning the proposed, domestic water supply. The analysis has been completed and submitted to the State Engineer's Office (SEO) for review; however, at the time this addendum was completed, no written response from the SEO had been received by the Planning Department. Since the date of the last continuance, the following information has been submitted to the Planning Department for review: 1] The Colorado Geological Survey (CGS) asserts that erosion of the drainage basin, upstream from proposed Lot 1 will result in stream capture and increase the amount of flooding across this lot. Pursuant to the CGS written responses, the proposed building envelope has been further evaluated by the applicant's engineer and geologist. This evaluation has considered the size of the upstream drainage basin, the 100 year flood flow rate and the relative elevation of the building envelope. This study concludes that flood flows in excess of the 100 year flood would not affect the building envelope as it is currently proposed. See letters and information, pages /0 The engineering evaluation states that the landslide deposits on proposed Lot 2 are not active and proposes that, if approved, the building envelope be further evaluated with site specific testing at the time of building permit submittal. 2] The Supplemental Water Supply Report has been reviewed by staff and forwarded to the SEO for its review and additional comment. To, date, the SEO has not provided its written opinion concerning injury to senior water rights. Based on this supplemental water supply information, it appears that the flow of the spring is sufficient to provide a domestic supply to the subdivision lots. Staff notes that the Subdivision Regulations are silent to an actual, physical supply that is sufficient to serve the needs of a particular subdivision. In staff's opinion, this water supply is marginal and pushes the limit of a physical water supply. However, in staff's experience with Garfield County, a more -detailed physical water supply report, for a subdivision of this size. has never been submitted for review. If the engineer's calculations and assumptions concerning the long-term flow rate from the spring are correct, then an adequate, in-house water supply probably exists. See Report, pages 0— 6 % . Based on the information reviewed in this application, staff would be inclined to recommend APPROVAL of the Ponderosa Subdivision pursuant to appropriate findings and approval conditions. However, this information notwithstanding, staff is reluctant to usurp the authority of the State Engineer's Office, due to the staffs philosophy that the SEO is the most qualified in making decisions concerning the adequacy and legality of a water supply. The Planning Commission may do one of the following: 1] Continue the hearing, to a date certain, to allow the applicant time to further address the concerns raised by the SEO. 2] Deny the request on the grounds that the subdivision has not demonstrated an adequate physical and legal water supply. 3] Approve the application pursuant to the following suggested findings and conditions: V. SUGGESTED FINDINGS 1. That proper publication and public notice and posting were provided as required by law for the hearing before the Planning Commission. 2. That the hearing before the Planning Commission was extensive and complete, that all pertinent facts, matters and issues were submitted and that all interested parties were heard at the hearing. That the proposed subdivision of land is in general conformity with the recommendations set forth in the Comprehensive Plan for the unincorporated area of the County. 4. That the proposed subdivision of land conforms to the Garfield County Zoning Resolution. That all data, surveys, analyses, studies, plans and designs as are required by the State of Colorado and Garfield County have been submitted and, in addition, have been found to meet the requirements of the Garfield County Subdivision Regulations. VL RECOMMENDATION Based on the above analysis, staff recommends APPROVAL, subject to the following conditions: 1. That all representations of the applicant, either within the application or stated at the meeting before the Planning Commission, shall be considered conditions of approval. 2. A Final Plat shall be submitted, indicating the legal description of the property, dimension and area of the proposed lots, access to a public right-of-way, and any proposed easements for setbacks, water supply, drainage, irrigation ditches, access, utilities, etc. The applicant shall prepare and submit a Subdivision Improvements Agreement addressing all on-site improvements, prior to the submittal of a final plat. That the applicant shall submit school site acquisition fees, for the creation of the additional subdivision parcel, prior to authorization of a final plat. The applicant shall be notified of the actual fee that will be applicable at time of submittal of the final plat. That the following plat notes shall be included on the final plat: "Pursuant to C.R.S. 30-28-136(h)(I), the State Engineer has found that the water supply for this subdivision will result in the material injury of senior water rights. All prospective future owners are advised to seek a copy of the State Engineer's opinion." "The minimum defensible space distance shall be 30 feet on level terrain, plus appropriate modification to recognize the increased rate of fire spread at sloped sites. The methodology described in "Determining Safety Zone Dimensions, Wildfire Safety Guidelines for Rural Homeowners," (Colorado State Forest Service) shall be used to determine defensible space requirements for the required defensible space within building envelopes in areas exceeding five (5) percent grade." "Soil conditions on the site may require engineered septic systems and will require engineered building foundations based on site-specific soils testing." "The individual lot owners shall be responsible for the control of noxious weeds." That the final plat submittal include a copy of a computer disk of the plat data, formatted for use on the County Assessor's CAD system. That all proposed lots shall comply with the Garfield County Zoning Resolution of 1978, as amended, and any building shall comply with the 1994 Uniform Building Code, as adopted. The water rights associated with the Ponderosa Spring #2, together with the well permit(s), shall be transferred by the developer to a homeowner's association which shall have the power and the duty to enforce compliance by lot owners with the terms and conditions of the well permit. Appropriate Protective Covenants shall further require compliance with the terms and conditions of the well permit. 9. That the following provisions be included in the protective covenants governing the subdivision: One (1) dog will be allowed for each residential unit within this subdivision and the dog shall be required to be confined within the owner's property boundaries. Enforcement provisions shall be developed for allowing the removal of a dog from the area, as a final remedy in worst cases. No open hearth solid -fuel fireplaces will be allowed anywhere within this subdivision. One (1) new solid -fuel burning stove as defined by C.R.S. 25-7-401, et. seq., and the regulations promulgated thereunder, will be allowed in any dwelling unit. All dwelling units will be allowed an unrestricted number of natural gas burning stoves and appliances. All exterior lighting shall be the minimum amount necessary and all exterior lighting shall be directed inward, towards the interior of the subdivision, except that provisions may be made to allow for safety lighting that goes beyond the property boundaries. 4fvc_o -/D P.O. Box 1908 1005 Cooper Ave. Glenwood Springs, CO 81602 Z4NCANELL4 4140 4S!OCIATE5, INC. ENGINEERING CONSULTANTS December 17, 1997 Eric McCafferty Garfield County Building & Planning Dept. 109 8th Street Suite 303 Glenwood Springs, CO 81601 Re: Ponderosa Subdivision Dear Eric: (970) 945-5700 (970) 945-1253 Fax r-� 9 t�99 The Letter from the Colorado Geological Survey and the geologic mapping for the area identify all of Lot #1 as Tying within an alluvial fan deposit. We have concluded that the Building Envelope as stated on the Preliminary Plat is acceptable. No building should be permitted within 25 feet of the existing drainage on Lot 1 as shown by the building envelope. If you have any questions, please call our office at (970) 945-5700. Very truly yours, Zancanella & Associates, Inc. d-r-Cwc Q Terri L. Lance Geologist cc: John Savage L:196339 Wlcferty3.wpd PRELIMINARY PLAT: PONDEROSA S UBDI L'IS1ION A PORTION OF THE SWI/4 SW1/4 OF SECTION 5, TOWNSHIP 5 SOUTH, RANGE 93 WEST OF THE SIXTH PRINCIPAL MERIDIAN GARFIELD COUNTY, COLORADO 11E TO T1+E SCUT54 1/16 CORNER Or EECTICNS 5 t 5? S69•A9^N - 232.4.3'RINGS: S89'49'00"1/ 'N ///''' PCANT Cr 3ECNNMC: FC&2O RN / ANO AEUYINRIN OAP. L( 5933 1// tLEvA1Cn - 627193 BASIS OF BPA ''oro C!g1P7r41T 4 `QO9CJ e a4.G`'. 1, . si foo gc„,\,5 N. { i'\' N. 1091.31' -DFL-41:___ -``—� 2] ,,— A 7Ss. �, I,\01.0➢' N. a7��721 2 T $" A. BULLING CIALCPE • it 1 k.\ = la in \\N. 9. LOT 1 1 n1. `' N.., 3.0d AC..: 'AE'_ LCCAnCN '....•••• 79.' TO lYc rc5: \' 96 PC4.0E4ROSA LCCAncN CF SPR91C I T01A' TO 'NE +EST USE 0r SECION 7 i 1992' TO r%IE SOUTH UNE CrSECT * 3 • Leta. 6u., 101,..,„ E Ave, le Q� •-- • Lcca1 DroAky.... \ N. UNE Cr SECCy S i \ \ \ 133r TO T4+-SG1oN \ \ ) ' , _ N. L 9€ J SEcnc, 5 �. �'� ELE'lAnCN 6274.21 N. E215nN0 ASPHALT ▪ NA.. e7. N. F C'w_'NE •� \ \ \ ,S+V% Ex1011NC CAA'w \ ytiA N. AN AT7CANE! LCENSEC rC PRACTICE LAW STA Or CCLC.'TACO. 00 NERE3Y ?')Y r..AT ALL CZOICAOCANS TO it:C. AS OEEC.4BEC CN 75415 TINA!. 51.).1 AA( TRr ANSI CLCAR CP N'. CL#I*S CR ENCUE.BRANCE3 c RECCRO ..o RlnTHER 154Ar r541S SCA, IS :N SU95rumAL CCUPUANCE 'MTw T1 0 CARFrl.OCCUNrY S:CN RECUUnCNS CP 19e, 347E J'7P.'? 7T '1TP 5. 9EGrTSR. 00 HEREBY STATE TNAT I AN A AEGSTEREO 1.490 UCZISOZO URGER 154E LAWS Or 154E 5141E Or 00129400. THAT ! i5 A TRUE. CC55027 AN0 CCua9E7E P1. r Cr 1.1E 44.•nrrA...1 r` AS .10 OUT. 51..rO. oECIC.troo ..o SCYAH HERECN. THAT *AS *ACE %RCN AN ACCURATE SURVEY Cr SAID 59CPERTY BY uE .R *1 SUP ERASCN ANO CORRECTLY S.C.'S THC LCCAr10N AN0 s Or NE LOTS. EASE04ENrS ANO STREETS CP SATO SUBOIV *ION ;Aur APE 5TAREO UPON 1.0 0514290 91 CCva1„AHCE 9.99 L REO:: LAocwS CONERNINC 15,E SURCnAS'CN CS LANG. ;S A.ERFCr 1 NAYE SET uY NANO ANO TEAL n*S OAY CP • A O. 19_• ciry ycv0 q•S FCA CCN =.'Ii ANO FCPV C\1.Y ANC 7,21-7E3 5ACCU-.1CY101 CA'ANpSUR\E'fS. CR CRA: �.v. Pt:RS:ANT TC 14710 ._ EC) EC ). \ 4° c0 ` -s .L?VP TJRr: C'Pva TT w T3,e•• L 2 o)/� _ Sso 1C. • Ia.WeT9 S. IPOs '; \ 05,S1NC 3a' CVR E..FK.CCCN I CISTAAI E I 10356 1J ° RL �.,. 61650 : i 1 ' , 1 6\: ;1\ \• \ \C--- ;d ''1 \\` \`.. \ "173's \\ \' le \ • \ \ \\. \ ,. ESS^NC 341' CLa r0UNO 110.5*? RIGT-:j�NAr \ NCNUN1.7 - 3' 09402 CAP SET i9 CONC./CTE. STAVP> NT. AN CtE'IAIC.• Cr AT.R.2) - BASS Or ELE.AnC+. ne s co:o':. w - 1.7..3.3' TO -� 1.0 *E51 I/95 CV1E.R CCNNCI'• 70 5ECn2N5 5 t a .. .1ra STATE OF COLORADO COLORADO GEOLOGICAL SURVEY Division of Minerals and Geology Department of Natural Resources 1313 Sherman Street, Room 715 Denver, Colorado 80203 Phone (303)866-2611 FAX (303) 866-2461 December 23, 1997 Mr. Eric McCafferty Garfield County Department Building and Planning 109 8th Street. Suite 303 Glenwood Springs, CO 81601 GA' -98-0010 ` RE: Resubmittal of Ponderosa Subdivision Geologic Hazard Review Dear Mr. McCafferty: DEPARTMENT OF NATURAL RESOURCES Rov Romer Governor lames S. Lochh-,iri Executive Director Michael B. Long Division Director Vicki Cowart State Geologist and Director At your request and in accordance to Senate Bill 35 (1972) this office has reviewed the geologic hazard report for the Ponderosa Subdivision. The CGS previously reviewed this property in a letter to you, dated October 30, 1997. The subdivision contains two proposed lots. Lot #1 As stated in the earlier letter, the biggest concern the CGS has with this subdivision is debris flow and flash flooding. The lower small basin behind the subdivision property, which drains between the two lots, will ultimately capture the higher main drainage way that leaves the steep basin within the hogback. Presently a very narrow, very short saddle or barrier of soft claystone separates the higher and larger drainage channel from the lower drainage basin. It is the CGS's opinion that this narrow saddle will not last long and the main drainage flow will soon be redirected. That `stream capture' will result in larger storm flows toward the two lots. The recent Geologic Hazard Report from Zancanella and Associates, Inc. does not address this stream capture eventuality. We believe that the southeastern portion of the building envelop, as currently shown on the preliminary plat. lie within a flash flood and debris flow hazardous area. A suitable building envelope must be restricted to the western half of the lot. Lot #2 We do not recommend acceptance of the northern portion of the building envelope as shown in the geologic hazard report without additional geotechnical data. The steeper grades of that portion of the lot #2. north of the power line easement, lie within the mapped landslide. The existing location of the trailer home on this site is suitable but consideration of siting a new structure lower in the lot must factor in the tlooding potential stated above. If you have any questions please contact this office at (303) 894-2167. Sincerely, Jonathan L. White Engineering Geologist P.O. Box 1908 1005 Cooper Ave. Glenwood Springs, CO 81602 Z4Nc4NELL4 At10 455OCI4 TES, INC. ENG114EEf1ING CONSULTANTS January 8, 1998 Mr. Eric McCafferty Garfield County Building & Planning Dept. 109 8`h Street Suite 303 Glenwood Springs, CO 81601 (970) 945-5700 (970) 945-1253 Fax o9,. Re: Ponderosa Subdivision- Geologic Investigations Dear Eric: We have prepared this letter to address two concerns raised by the Colorado Geological Survey (CGS) pertaining to the above referenced project. Debris Flow Flooding - Currently the majority of runoff near the subject site flows towards and crosses Highway 13 at a point northwest of the proposed subdivision. The CGS has identified a critical channel reach above the property which is at risk of redirecting flood runoff and debris flows towards the existing channel which currently runs through the proposed Lot 1 of the subdivision This channel currently serves a minor basin area above the subdivision. Assuming a large flood event (100 yr+) would be redirected to the existing channel on Lot 1 from the larger basin to the northwest, we have further limited the building envelopes on the two lots to offer additional protection for habitable structures. The recommended building envelopes are identified on the attached Figure 1. The proposed building envelopes are located at least 4 feet above the existing channel. The capacity of the channel at this depth is approximately 1,500 cubic feet per second (cfs). The 100 year flood flow rate was conservatively estimated to be 450 cfs. The 100 year flood was calculated using procedures outlined in the Soil Conservation Service Technical Release 55 and takes into account the steep rocky terrain of the Hogback area. The tributary area for the flood was measured to be 245 acres (0.38 sq mi) and assumes the all up gradient lands have flows redirected to the subject channel. The existing channel has enough capacity to carry flows significantly greater than the 100 year flood for all of the potential contributing up gradient basin. Landslide Deposits lot 2 - We do not believe the landslide is active. We recommend that site specific soil test be conducted at any future proposed house site. To expend funds on soil test at general locations is not prudent at this time. Page -1- If you have any questions, please call our office at (970) 945-5700. Very truly yours, Zancanella & Associates, Inc. 2L. Christopher M p anera, P.E. Thomas A. Zancanella, P.E. President cc: Kenneth Rose John Savage \\Gateway 48650\f\96339\Mcferty4.wpd Page -2- 9- tfr PRELIMINARY PLAT: P O DEl O.SA S U_BDI yIS'ION A PORTION OF THE SW1/4 SWY1/ OF SECTION 5, TOWNSHIP .5 SOUTH, .RANGE 93 FrrEST • OF THE .SIXTH PRINCIPAL MERIDIAN GARFIELD COUNTY, COLORADO - Tc 7,•C SCL'1N 1/1) �p.c.. Cr R •'ri•c ra-rrj r� Melt C% BCC:NNINC: rCt:vc /44 C A ANO ACL•YU 1.34 CAP. L:( •.9:3 L1 hA-6+ - 5271]] 2 G BASS 07 BEARINGS' S7.9.49•CO"1l \ j '!N, pCNC/_?RCU /1 • lcuccv cf •Ja?C j 101. TO INC ',EST LNE 1 1ECr..0 . S a 199T TO r.E 2U-4 I:NE cr 2.:7cN • Lala Bv1(1 • t. E tope_ zg�O . � LCC 11 DrAtAk'� ..As ow Rev; sec/ 8143. Er u.1Dcs 1 r 1q� \ 1001.41 ' -. . N70./.D.:•. li77 `N2"'A7 CI Z, N .14• \\ LOT� . e • LNZ act "° • Nj. • • J )a 4:S:• wN t \ e �• ' � ' 4 cam.^:. H�� � ..r.;03? + A77C:.tr! L1C. Z: iC PRAC-00 L w CO N._ 0;T GR. -r 1A- f.. co c.oCNS TO __.0 rw-_C"•!C'.. c. NIS. 11w Al P'...r Aa!• rR•_ . O C •1R Cr S 0='C.YaPANCiz C. R:e.:.al w0 P R'.C) D.Ar THIS S.: ._w a 11 _.'Nr,Ar_ cCarPUA.0 YN.-n 0- c//r:=-CCLNTY 0A.'t vca•v rrn-nr,� Tw ". •.-•. CC I.C:i3'r S-A- Ar I AY A 2c.-ta_] LW.O ac? 711.0 L vrs c 0 SRA c a CCLCRAC0. THAT' • S . 1 GC. C.R Z- AN0 CCR. z P. -Ar Cr 11,5.J.• AS U�: CJ r, ]'1.-]. 0000.700 Aw0 0?C'ma Y(MCN. 01AT • RA C. rAC:1 Ar ACzou i 1LR•.ET Cr S ,0 iscPf4T•' 9T YE C.' YT 5.:-. CI w0 CRP.;•013.T A z n:zu•su. c LA -c. :Z •'•• 'E"l I) 00 001' YL T o,.c 60 00. i r• OAT Cf AA .... P•. ..A. :AL! C.]•: 171.1. r-CCr SLRSE'rS, `.O c -tee: `'G; ; =� t yr \ i 2 L � CrSTriC :o• GAP \ \ \\ Ca \ �. •d Ags>. • GQ) c• C 4 1� L• 1 _,t rn'/-7 C•�,rC :s" rJ? IN CC}•C _ r Aw BASS CF `ia .:Cn - 727.55' 10 Ksr /1) cT•wi_R cCwucN .0 _c-CNs S L 5 P; yre,I 0. 1. P.O. Box 1908 1005 Cooper Ave. Glenwood Springs, CO 81602 Z4NC4NELL4 AM 4SSOCI4TE5,INC. -^-, _/ ENGINEERING CONSULTANTS December 10, 1997 Mr. Eric McCafferty Garfield County Planning Dept. 109 - 8`h Street, Suite 303 Glenwood Springs, CO 81601 DEG (970) 945-5700 (970) 945-1253 Fax RE: Ponderosa Subdivision - Supplemental Water Supply Investigations Dear Eric: Zancanella & Associates, Inc. has conducted additional investigations into the water supply of the Ponderosa Subdivision being proposed by Mr. Kenneth Rose. We have prepared this letter to summarize additional work which has been completed and to highlight the issues surrounding the proposed water supply. This letter should be considered supplemental to our letter dated August 19, 1997. As stated in our earlier letter, and supported by additional research and developments, we believe the proposed water supply will provide an adequate water supply to serve the in-house needs of the two lot subdivision. Background History As you may recall, the demands for the development were based on in-house uses only for two single family residences (one unit per lot). Each house was estimated to have 3.5 people each using 100 gallons per day for a total of 350 gallons per day per house, or 700 gallons per day for the development. We believe this estimate to be slightly conservative and provides a good planning estimate. We have seen water estimates used by others of 80 gallons per person per day. We believe the lower use estimates are justifiable for homes with low water use fixtures and appliances. The existing home at the site, which utilizes such fixtures, has averaged approximately 70 gallons per day diverted from Ponderosa Spring No. 2 since a meter was installed last July. The supply of irrigation water is not a project goal of the developer and should be considered a supplemental demand. We have previously recommended that a note on the subdivision plat be required noting the irrigation supply is supplemental to the in-house demands of the development. The Rose water rights include irrigation uses. The water supply for the development consists of a well and the Ponderosa Spring Nos. 1 and 2. The well is not currently used at the existing home. The springs are located on the adjacent Bureau of Land Management (BLM) property at the base of the Grand Hogback. The Ponderosa Spring No. 2 was developed in February of 1997 and currently serves the existing home. The spring can be visually observed exiting an scarp on the hillside. The flows exit the scarp and pass through a vegetated area approximately 15 feet in length prior to entering an infiltration gallery with a spring collection box. The Ponderosa Spring No.2 spring box installed by Mr. Rose is elevated on washed rock material which allows for a bypass flow to a lower elevation drain pipe which collects portions of the uncaptured spring flows and delivers it to a small watering area (5 -foot diameter by 1 -foot deep pond). It should be noted that the spring development is not situated on top of formation and additional uncaptured spring flows exist below the Rose improvements. The small watering area was constructed with a impermeable liner and then covered with native rock material. The watering area was developed by Mr. Rose to supply a bypass flow for wildlife watering water rights developed by the BLM. The BLM water rights for the spring were adjudicated junior to Mr. Roses rights in the Ponderosa Springs. However, in consolidated Case Nos. 95CW111 and 96CW166 the decree remarks that the Rose rights are to be administered junior to the BLM rights as per a stipulation attached to the decree. Investigation of the physical supplies available from the Ponderosa Spring No.2 were undertaken with a field visit and implementation of a spring monitoring program in October of 1996. The geologic formation that the spring exits appears to be comprised of a low permeable cemented material. The spring has created a small gully located on the hillside below the base of the Hogback. Minimal vegetation and water pooling was observed at the original spring. Vegetation or flows were undetectable approximately 70 feet below its discharge where it appeared all of the springs flow had percolated back into the earth. Prior to the spring development, the spring flows were measured to be 959 gallons per day. Measurements taken the following February and May indicated that the spring flows maintained at a fairly consistent level. The measured flows did not include the flows being bypassed to the BLM. A summary of spring flow data is presented in the following Table 1. Table 1 Ponderosa S• rin • #2 - Flow Measurements Date Flow (gal/min) Flow (gal/day) October 17, 1996 " 0.66 959 February 15, 1997 0.75 1,080 May 15, 1997 0.65 936 June 14, 1997 0.83 1,195 August 10, 1997 0.81 1,166 September 15,1997 1 0.87 1,252 October 19, 1997 1.08 1,555 November 15, 1997 1.09 1,570 Measured prior to spring development. Based on the installation of the existing storage tanks, it was our opinion that the single spring would serve the needs for the two lot development. However, the production of the Page -2- /; - spring during a severe drought period was unknown due to the lack of observations during such a period. It was our opinion, that based on the consistent flows measured over the winter of 1996 and 1997, the aquifer exhibited characteristics that it had the ability to store inflow and make releases at steady levels. In other words, the groundwater aquifer characteristics which prevents this spring from experiencing high "gushing" discharges fluctuating through time during varying precipitation events, supports its ability to provide continued supply during dry periods. In the event that reduced spring flows occurred during a drought period it was assumed that the Ponderosa Spring No.1 could be developed to enhance the supply. Review of the proposed water supply by the Colorado Division of Water Resources was completed by Steve Lautenschlager and summarized in a letter dated October 27,1997. It was the state's opinion that the proposed water supply plan would cause injury to the BLM's rights at the spring and was not adequate to meet the requirements of the proposed subdivision. The concern over the BLM injury is based on the BLM's instantaneous diversion amount of 0.007 cfs (3.1 gallons per minute) which was stipulated to be senior in priority to the Rose rights. This amount is obviously greater than the observed flows at the spring and theoretically could require the Rose rights to bypass all flows to the BLM. We believe that a potential call from the BLM is unrealistic due to the location and decreed use of the BLM rights. In order for the BLM to place a call on the rights it would require beneficial use of the spring flows. We believe a call by the BLM for the entire spring flows would result in water percolating back into the ground below any watering areas. Any water called and not being used to meet the decreed wildlife uses would thus be considered wasteful which could nullify the call. Additionally, the lack of any constructed diversion facilities by the BLM and the inability to measure uncaptured spring flows raises doubts as to wether a call could be enforced. It is our understanding that the BLM requested the senior status to the Rose rights to insure the existing vegetation was not dried up and enough flows were available to meet wildlife watering demands. Based on improvements to the spring which and the addition of the bypass/watering area, we believe the BLM was satisfied with the water split at the spring. This is evidenced by the letter prepared by Roy Smith of the BLM who indicated the developments by Mr. Rose were adequate for the BLM uses and would not be subject to a call. To further define the BLM's position, a subsequent agreement (attached) was approved by the BLM which quantified the volume of water which could be called. The volume amount was determined based on a measurement of the bypass flow at the spring. Based on the agreement with the BLM and other issues pertaining to the administration of these rights, which will be discussed later in this letter, we do not believe a call will be placed by the BLM or be administered against the Rose rights as long as the current bypass flows are maintained. It has been our experience that the state typically does not require proof of the dry year or "drought" yield of groundwater supply's. Such estimates are difficult to examine due to the various unknown physical characteristics associated with the aquifer combined with the Page -3- unknown recharge amounts (typically precipitation). Nonetheless, due to the relatively small discharge flows of the spring, additional investigations are warranted to better understand the potential future flow production rates. Our investigations into the reliability of the spring have been focused on examining the recent spring flows and precipitation events and comparing them to historic precipitation records and streamflow conditions in the area of the spring. Additionally, we believe the reliability of the spring is best supported by historic accounts of similar spring users near the proposed subdivision. Physical Water Supply The hydrologic cycle is a complex process which has many factors which determine the amount of precipitation that is converted to either surface runoff or groundwater recharge. A detailed groundwater study of the subject aquifer is not feasible and still would require numerous assumptions to estimate future spring production rates. However, we can examine past precipitation data to gauge the relative impact of historic drought conditions in the area of the spring. Although the comparison of historic precipitation data can not tell us directly what the future flows will be, it can act as a barometer to the severity of historic drought conditions as compared against average conditions. The Ponderosa Subdivision is located at the base of the Grand Hogback several miles north of Rifle. The estimated average annual precipitation at the site is approximately 15 to 16 inches per year based on isoheytal maps prepared by the Colorado Climate Center. National Weather Service cooperative weather stations have recorded historic precipitation records in this area for the locations of Grand Junction, Rifle, Meeker, Glenwood Springs, and the Altenbern Ranch near Debeque. The closest weather station would be the City of Rifle. Examination of historic precipitation data for the Rifle station indicates the long term annual average is approximately 11.6 inches per year. The attached Table 2 summarizes the available monthly and annual precipitation amounts recorded at the Rifle station for the periods of 1940 to 1996. The following Table 3 summarizes the long term average annual precipitation values for the other weather stations. Table 3 - Average Annual Precipitation (inches) Station Grand Jct Rifle Meeker Glnwd Spgs Altenbern Precip. 8.9 11.6 13.3 16.7 16.9 As can be seen in Table 2, the precipitation values range from a low at Grand Junction of approximately 8.9 inches per year to a high at Altenbern of 16.7 inches per year. The lowest annual recorded precipitation at the Rifle station for a complete year occurred in 1962 and totaled 8.0 inches. It is interesting to note that although we believe Rifle could be classified as an area below the state average precipitation, the relative difference between its average precipitation and its driest record period is not extreme (approximately 69% or 8.0/11.6). The attached Table 4 summarizes recent monthly precipitation data for the above stations. The Rifle station was discontinued in July of 1996 to August of 1997. During this period Page -4- /L/ we have estimated the monthly precipitation amounts for Rifle by averaging the other station monthly totals prorated by the ratio of the stations long term averages. The precipitation data for the year prior to the initial spring flow measurements totaled 11.3 inches and can be considered average. We believe the spring flows observed during the winter of 1996 to 1997 were average discharge levels experienced under average precipitation conditions. Therefore, average flows from the spring are approximately 1,000 gallons per day. Assuming the dry year production of the spring is reduced by the same ratio as the dry year versus average year precipitation levels, then the dry year flow of Spring No.2 would be approximately 690 gallons per day (1,000 gallons/day * 69%). Available streamflow records were examined for a gaging station maintained on Rifle Creek for the period of 1939 to 1964. Unit runoff values were determined for the winter periods which we believe more accurately represents groundwater flow contributions versus surface runoff. The average unit runoff during this period was calculated to be 0.51 inches. The driest or drought year value was recorded in 1954 and was approximately 0.27 inches. Although the runoff characteristics of a large stream can not be correlated directly to the spring flows, the ratio of the average versus driest year records aids as an additional tool to show extreme conditions. Based on the extreme streamflow ratio of 50% (0.27/0.51), and assuming the spring were to experience similar characteristics, the Rose dry year flows would average approximately 500 gallons per day from the Ponderosa Spring No. 2. We believe that if the spring were to drop to these levels, then the Ponderosa Spring No. 1 would have to be developed to meet the full 700 gallons per day demands. The flow production of the Spring No. 1 has been previously estimated by Rose and the BLM to be equivalent to the Flows of Spring No. 2. Conservatively assuming that the Spring No. 1 flows were 50% of Spring No. 2, then the combined supply would be sufficient to meet the in-house demands of the development. We do not believe the development of the second spring will be required. The above Table 1 shows that spring flows have steadily increased during the past 6 months of monitoring. The increased spring flows can be correlated with above average rainfall rates during the last 8 months which have totaled approximately 14.5 inches. Review of the Division of Water Resources 1996 water rights tabulation indicates that multiple spring rights have been adjudicated along the base of the Hogback near the subject site. We believe there is a confining layer at the base of the Hogback which forces the groundwater to the surface. The nearest water right is the Corlett Spring located at the next residence below Rose's property along Highway 13. The approximate spring location is shown on Figure No. 1. Decreed conditional in 1980 for 0.018 cfs (8.0 gpm), this right has been made absolute for only 0.0033 cfs (1.5 gpm) which is approximately equal to the magnitude of the total flow production from the Ponderosa Spring No. 2. The Corlett Spring was developed by Mr. "Buzz" Corlett who has lived and worked in the area along the Hogback for over 50 years. Mr. Corlett indicated that his spring, along with multiple other springs which he has developed for other individuals along the Hogback do not fluctuate seasonally or annually. Mr. Corlett also indicated that his spring has always been adequate to serve his residence and that he has never seen any of the springs along the Hogback dry up. These include springs developed by other domestic users as well as BLM springs he has observed while hiking or hunting. Mr. Corlett was very cooperative in our discussions and indicated the willingness to discuss the history of this area as may be required in the future. Water Rights Administration The Rose and BLM spring water rights are only administered amongst each other with no water rights uphill from the spring. Although water rights below the spring exist on Government Creek, we do not believe they materially contribute to the Government Creek surface flows and could be administered as a futile call. This position was recognized by the District 39 water commissioner. Based on the current development of the spring and the agreement with the BLM, we do not believe the spring flows diverted by Rose could be called out by the BLM rights. Even without the current agreement, the BLM would have to demonstrate beneficial uses of any additional called water. Wildlife water use demands are not a typical demand estimate that we have examined in the past and is therefore difficult to quantify. However, for discussion purposes we can estimate the ability of the spring to provide water demands for deer which we believe would pose the largest demand potential for this area. The daily consumption requirement of a deer is approximately 4.6 gallons per day. This is based on water use requirements for livestock (15 gpd) prorated by the daily forage requirements between the two animals. The current bypass of water is approximately 176 gallons per day. The current bypass flows could therefore supply the water needs of approximately 38 deer daily. This high demand is improbable based on wildlife observations in this area. We believe the BLM demand will be satisfied by the current bypass which will also be served by the lowest level of water produced from the spring. Additional calls by the BLM are unrealistic. We believe this opinion is supported by the cooperative efforts which have been demonstrated by the BLM with regard to this issue. Recent discussions with the Division of Water Resources have indicated that the state may not administratively recognize the agreement between the two parties. This position is based on a policy of not recognizing "selective calls". Our understanding of the definition of the selective call is that a senior water right can't selectively not place a call against one or more junior rights while still placing a calls against other junior rights. We agree with this policy which we believe equally protects all water rights. However, we do not feel that it is applicable to the spring because there are no other water rights administered in connection with the spring (i.e. no upstream rights and futile call downstream). Furthermore, if the state were to strictly enforce this administration policy and not recognize the agreement, then we believe that the state would not be able to enforce the stipulation agreement of the water rights in the decree. This is because the stipulation essentially allows the senior rights of Rose in the spring not to place a call against the junior water rights of the BLM. Or in other words the stipulation with the subordination of the Rose rights to the BLM fits the definition of a selective call. Summary The following comments summarize our opinion of the proposed water supply. 1. The current physical water supply produced from Ponderosa Spring No. 2 is sufficient to meet the in-house demands of the proposed development. It is not the goal of the developer or the water supply to provide a reliable yield for irrigation uses. The plat should note the priority of in-house water uses over irrigation use. 2. The aquifer supplying the spring has shown characteristics that it has the ability to detain inflow (precipitation) and produce steady flows. The low transmissivity of the aquifer will therefore will still produce flows even during or following periods of dry or "drought" conditions. The aquifer properties are supported by the consistent flows observed at the spring through the first winter of observations followed by a moderate increase of flows during a period in which the precipitation is above average. 3. The spring flows observed during initial monitoring stages are assumed to be average conditions based on the average amount of precipitation which occurred during the previous year. The average spring flow available to the Rose rights at the Ponderosa Spring No. 2 are 1,000 gallons per day. Demands of the development have been conservatively estimated to be 700 gallons per day. 4. Average annual precipitation recorded at the Rifle weather station is 11.6 inches per year. The lowest year of precipitation over the last 57 years has been 8.0 inches. We believe the ratio between these values (69%) is not extreme. The Rifle area appears to be below average and therefore the ratio to the drought condition is not as drastic as might be compared for other areas in the state where the average precipitation values are higher. Assuming this ratio correlates to the same percentage of reduced spring flows, then the single spring could still meet the development's demands. 5. Streamflow records for Rifle Creek have indicated that the single winter season lowest streamflow amount was approximately 50% of average streamflow conditions. Assuming similar conditions developed for the spring , then 500 gallons per day would be available from Spring No. 2. If such an event were to occur, either the Spring No. 1 could be developed to meet the full demands or water conservation measures could be implemented by the development for the drought conditions. Due to the relative small size of the development we do not believe the development of Ponderosa Spring No. 1 is warranted at this time. 6. The best indicator of future production rates of the spring can be based on the production of similar type springs located near the proposed subdivision. Multiple water rights have been developed along the base of the Hogback with similar geographic locations as the subject springs. The nearest spring was decreed by Buzz Corlett who has indicated that his spring has not fluctuated through time and Page -7- has always provided a reliable supply to his residence. Mr. Corlett has also developed springs for others in this area as well as observed non developed springs which have all maintained flows even during dry years. We believe the Corlett spring is very similar to the Ponderosa Spring based on geographic locations and observed flow rates. 7 The development of the spring allows a physical bypass of water to the BLM for wildlife watering. The bypass flows were measured to be 176 gallons per day. Any reductions in spring flows will occur to the Rose diversions with the lower level BLM flows maintained. 8. BLM has acknowledged the spring improvements completed by Mr. Rose and has subsequently offered cooperation to demonstrate their intention of not placing a call on the Rose rights. The BLM's cooperation has been demonstrated by a letter submittal and agreement from the BLM's water rights coordinator. The agreement requires Rose to provide 160 gallons per day of bypass flow. 9. Additional BLM calls above the current bypass requirements are unrealistic due to the lack of demands which we believe could be claimed. This assumes that a call from the BLM would have to be consumed otherwise the water not utilized could be considered wasteful. The administerability of a BLM call is questionable to the lack of any diversion structures, measuring devices, and uncaptured spring flows. 10. We believe the water split agreement with the BLM can be administratively operated due to the lack of any calling upstream or downstream rights. If the policy of a no "selective calls" is enforced by the Division of Water Resources, then we believe the state would also have to not enforce the selective call nature of the existing decreed stipulation. If you have any questions, please call our office at (970) 945-5700. Very truly yours, Zancanella & Associates, Inc. Christopher Manera, P.E. End cc: John Savage Kenneth Scott Rose \\Gateway 48650\f\96339\Mcferty2.wpd Table 2 Monthly Climatic Data for RIFLE for years 1940 1996 Station - 57031 Latitude - 3931 Longitude - 10747 Elevation - 5300 Total monthly precipitation. Jan Feb Mar Apr ' May Jun Jul Aug Sep Oct Nov Dec Annual 1940 162 128 94 144 40 23 86 169 206 172 86 110 14.2 1941 92 75 191 150 82 126 43 104 158 311 112 75 15.2 1942 47 100 84 141 35 20 127 43 57 126 55 20 8.6 ' 1943 99 42 146 23 • 178 150 39 253 53 131 16 76 12.1 1944 182 65 75 116 30 66 99 29 7 45 203 25 9.4 1945 36 114 131 112 122 140 75 65 32 97 88 66 10.8 • 1946 24 24 60 276 173 65 65 225 51 291 123 93' 14.7 I 1947 61 56 97 105 66 160 125 98 71 • 144 56 63 11.0 ; 1948 94 143 174 68 • 9 • 138 87 112 42 90 79 163 12.0 1949' 120 22 152 65' 29 80 109 109 131 60 21 64 9.6 1950' 186 48 36 56 42 2 163 25 117 21 67 111 8.7 1951 145 48 21 115 69 103 47 156 44 117 64 406 13.4 1952 105 25 180 16 78. 64 56 226 6 0 53 42. 8.5 1953 64 19 116. 127 173. 65 117 208 31 148 143 35' 12.5 1954 87, 29 86 93 76 155 150 194 232 146 152 57, 14.6 ' 1955 94 98 • 20 47 ' 171 54 78 139 15 ' 56 ' 169 72 10.1 1956 131. 131 20 127 9 12 154 85 0 85 49 82' 8.9 1957 275 91' 116 129. 279. 210 136 418 16 334 • 139 77 22.2 1958 25 101 102 . 62 ' 31 24 77 22 151 29 53 M 6.8 M 1959 62 154 401 167' 42' 97 • 10 240. 153 172 7 78 12.2 ' 1960 67 ' 126 119 62 53 , 20 2 55 51 52 61 58 7.3 1961 1 55 • 114 92 101 7 26 115 287 108 65 70 10.4 1962 104 219 17 97 51 16 23 12 69 89 52 47 8.0 1963 61 28 63 37 • 2 78 23 155 115 151 78 40 8.3 1964 65 14; 72 82 140 116 50, 101 96 3 105 110 9.5 . 1965' 67' 52 128 • 60 43. 110 203 36 231 52 104 58 • 11.4 1966: 53. 37 12 45. 111. 10 24 • 47• 45 172 39 241. 8.4 i 1967 54 , 34 ' 41 ! 50, 161 224 184 ' 107 135 • 43 - 57 ' 229 13.2 1968' 32; 213 39 1181 61 9 53 164 21 119 93 121 10.4 1969 264 111 : 22 481 21' 252 31, 143 166'' 363. 69 411 15.3 '' 1970 ' 62 20 ' 131 ' 97 2 ' 190 ' 174 77 178 ' 158 • 176 89 13.5 ' 1971 _ 98 35 42 94 110 T 61 , 91 157 , 179 • 74 188 ; 11.3 1972 , 15 5 16 79 109 • 66 71 60 197 344 96 221 12.8 1973 75 • 53 95 59 71 163 112 216 38 41 81 65 10.7 1974 148 52 76 81 T 60 98 89 46 87' 65 126 9.3 1975 84 111 146 80 108 102 • 42 10 25 61 61 94 9.2 1976. 52' 181. 145 89; 158 110 29 113 148 22 T 2 10.5 1977 76 21, 48. 46' 601 12 46' 233 112, 951 67 111 9.3 1978; 235, 92, 265; 116; 70' 57' 21' 70' 47 23, 157' 325' 14.8 1979 167 92 ' 147 40 3221 61 39 92 7 , 74 123 19 11.8 ' 1980 ' M M M 103 211 21 ' M' 144 36 M' 63 59' 6.4 M ' 1981 52, 33 78 39 • 283 104 224 145 36 294 73 127, 14.9 ; 1982' M M 126 8, M 55 47 72 293 122 156 32': 9.1 MI 1983 40 72 104 258 233 323 190 154 40 103 239 247 20.0 1984 34 8 120 194, 105 371 189 260 168 226 M 286 19.6 M 1985 108 78 304 260 155 45 241 30 146 323 359 127 21.8 ; 1986 45 109 78 223 • 128 21. 128 144 330 156 104 30 15.0 i 1987: 78 90 84 70• 97' 61 103 108 28 96 74 122 10.1 ! 1988 157 • 47. 45: 111: 56 109 80 71. 259 14 181 100 12.3 1989 82 158 47 61' 31' 20 263- 67. 77 • 117. 24 10' 9.6 ' 1990' M 93 41 128 76' 70 122 27 51 158 88 107: 9.6 M 1991. 117 28 129 74 31 • 65 86 99 173 197 90 50• 11.4 1992 19 61 • 112 30 229 75 213 60 146 161 97 64 12.7 1993 15311 240 155 100 155 29 M 8711 64 114 111 64 10.3 M 1995 33 111 95 88 1996 136 245 36 106 138 149 7.6 M L III IVP t 0b 92 M 239 881 204 37 143 81 27 M 10.6 M 46 51 6.2 Mi Avg 0.84 0.80 0.92 0.99 0.98 0.85 0.94 1.14 1.05 1.26 0.93 0.96 11.7 M= Missing data/incomplete records 12/09/97 05:46 PM RIFLEPCP.WK4 Table 4 Monthly Precipitation - inches Glenwood Altenbern Grand Meeker Rifle Springs (Debeque) Jct Jan -95 1.51 1.17 0.52 1.00 0.33 Feb -95 2.54 1.50 0.26 0.89 Mar -95 1.67 1.93 1.76 1.14 0.95 Apr -95 1.81 1.42 0.91 3.44 0.88 May -95 5.83 4.15 2.53 5.59 2.39 Jun -95 1.90 1.78 1.29 1.49 0.88 Jul -95 2.03 2.22 0.91 1.13 2.04 Aug -95 0.88 2.66 0.43 1.06 0.37 Sep -95 1.80 ! 2.57 ' 0.98 2.91 1.43 Oct -95 ' 1.15 1 0.62 0.19 l 1.41 0.81 Nov -95 2.55 I 0.64 0.17 i 1.49 0.27 Dec -95 2.81 '' 0.84 0.32 0.41 0.87 Jan -96 4.44 1.55' 0.36 1.95 1.36 i Feb -96 2.72 3.45 1.21 2.17 2.45 Mar -96' 0.67 0.86 0.39 1.14 0.36 Apr -96' 1.96 1.84 0.93 1.90 1.06 May -96' 1.21 1.02 0.84, 1.18 0.46 Jun -961 0.74 1.64 1 0.63. 1.03 0.51 Jul -96 1.18 1.77 0.70 ' 2.031 1.19 Est Aug -961 0.30 0.46' 0.021 0.53 0.25 Est Sep -96 i 2.92 2.16; 1.29 ',' 1.75 1.69 Est Oct -96 2.33 2.76 1.11 2.68 1.83 Est Nov -96 1.601 2.32 1.00 2.63 1.58 Est Dec -96' 2.521 1.29 0.37 1.32 1.07 Est I Jan -97 3.84: 2.60 0.31 1.66 1.58 Est ' Feb -97 0.40 0.49 0.13 0.89 0.39 Est Mar -97 : 0.77 I 0.21 0.42 ! 0.45 0.41 Est Apr -971 1.83 2.80 2.55 , 3.77 2.46 Est May -97 1 2.36 ' 2.29 1.54 1.87 1.72 Est Jun -97 1.32 ' 0.56 1 0.42 ; 0.89 0.66 Est Jul -97 1.77 0.72 ' 2.08 2.47 1.65 Est Aug -97 1.67 2.39 1.83 3.29 2.02 Est Sep -97 4.20 5.09 3.38 5.50 3.21 Oct -97 Nov -97 1.69 0.99 Long term Avg 16.73 Rifle ratio to Avg 16.52 8.88 0.69 0.70 13.33 11.6 1.31 0.87 Oct95 to Sep96 Apr97 to Nov97 11.3 Est 14.4 Est Est = Estimated Rifle station precipitation based on average of other monthly station readings and ratio of long time station averages 12/10/97 02:31 PM FRECIP.VVK4 DEC -05-97 FRI 11:51 JOHN w SAVAGE 9706250303 P•Ejs SUPPLEMENT TO LETTER AGREEMENT OF MAY 29, 1997 Reference: CO -932; 7250 Re: Ponderosa Springs; Div. 5: 95CW111/96CW166 The United States Department of the Interior, Bureau of Land Management, by its undersigned agent, agrees to the following terms to supplement the above referenced Letter Agreement: BLM agrees that its senior water rights in the above refer- .enc_ed_st.rJ tures_ of. 0-Q_Q7_cfs . are_be ng satisfied by the current construction and administration and further that as long as the existing wetlands upstream to Kenneth Rose's diversion structure are not interfered with and at least 160 gallons per day are al- lowed to flow to the tank/pond below the Rose diversion struc- ture, BLM agrees not to request an administrative call on the ju- nior water rights of Kenneth Scott Rose. BLM expects to be able to enter into a similar agreement as regards the seco d undeveloped spring, assuming similar diversion and s.1rage str tures are constructed. /en/ `�2 Date: Ve'Ce%16 d` / < 7 Roy Smith, Water Rights and Instream Flow Coordinator Colorado State Office, Bureau of Land Management 2850 Youngfield St., Lakewood, CO 80215-7076