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Home My WebLink AboutDrainage Report.pdfDRAINAGE REPORT FOR ELDER PROPERTY GARFIELD COUNTY, COLORADO PREPARED FOR: ED ELDER 6450 COUNTY ROAD 319 RIFLE, CO 81650 PREPARED BY: High Country Engineering, Inc. 1517 Blake Avenue, Suite 101 Glenwood Springs, CO 81601 (970) 945-8676 JANUARY 06, 2005 HCE JOB q' : R: 051062.00 x 0517 Jeremy J. Lucero, E.I. Design Engineer Reviewed by: MatthR. Langhorst, P.E. Colorado Registered Professional Engineer No. 39793 TABLE OF CONTENTS SECTION PAGE I. Property Description 3 II. Hydrology 3 III. Existing Conditions 3 IV. Proposed Conditions 4 V. Results and Recommendations 5 VI. Detention Pond 5 VII. Design Features 5 VIII. Summary 5 DRAWINGS: Sheet 1— Vicinity Map (8.5" x 11") Sheet 2 — SCS Soils Map (11" x 17") Sheet 3 — Existing Drainage Plan (24" x 36") Sheet 4 — Proposed Drainage Plan (24" x 36") Sheet 5 — NOAA-2yr (8.5" x 11") Sheet 6 — NOAA-25yr (8.5" x 11") Sheet 7 — NOAA-100yr (8.5" x 11") APPENDIX: A: Hydrology Calculations B: Additional Information Page 2 I. Property Description The Elder Property is a 15 acre parcel located approximately 4 miles south and east of the City of Rifle within Garfield County. More specifically the Elder Property is located in Lot 1 Section 19, Township 6 South, Range 92 West, of the 6th Principal Meridian. A Vicinity Map has been included as Sheet 1. II. Hydrology The hydrologic methods for this study are outlined in the Soil Conservation Service (SCS) publication "Procedures for Determining Peak Flows in Colorado" (1980) and the computer program AutoCAD Hydrology TR -55 Tabular Method. The development is located below an elevation of 8,000 ft, therefore, peak flows in this area will be rainfall derived. The soil types within the area of study are Torriorthents-Rocks and Potts loam (Sheet 2) as designated by the United States Department of Agriculture Soil Conservation. A brief description of these soils has been included on the soils map (11"x17") and is included in the appendix. The rainfall amounts were obtained using the Precipitation — Frequency Atlas of the Western United States published By the National Oceanic and Atmospheric Administration (NOAA). Using this atlas the precipitation corresponding to the 2 -yr, 24 hr storm event is 1.2 inches; the 25 -yr, 24 -hr storm event is 2.2 inches; and the 100 -yr, 24 -hr storm event produces 2.6 inches of precipitation. III. Existing Conditions The majority of the Elder Residence property currently consists of sagebrush and grass in fair to poor condition. A combined curve number, CN, of67 was used for the existing conditions on this site. The main portion of the EX -1 basin is at approximately 2 % slope. The existing drainage basins have been illustrated on the Existing Drainage Conditions map included at the end of this report (24" x 36"). The existing site is split by a ridgeline that runs from east to west across the property. The majority of runoff from both sides of the ridgeline sheet flow away from the site and are collected in two separate swales that convey flows toward the east to a large gulley which ultimately outfalls to Mamm Creek. A relatively small area in the northwest portion of the site drains west to the adjacent lot. The site was treated as a single drainage basin because the site generated runoff is collected in a common swale. Runoff for the site is tabulated in Table 1 and Table 2 below. Complete drainage calculations are included in Appendix A. Page 3 Table 1. Existing Basin C BASIN AREA (acre) CN Tc (min) EX 1 15.000 67 48 Table 2. Existing Basin R BASIN 25 -YR PEAK FLOW (cfs) 100 -YR PEAK FLOW (cfs) 100 -YR RUNOFF VOLUME (cu. ft.) EX 1 L19 2.41 18,723 IV. Proposed Conditions The proposed development will include a residential building, an office building, warehouse, truck wash steel barn, gravel surfaces, and future truck parking. The proposed truck parking located on the north side of the site has very similar drainage characteristics as existing conditions. The site will be regraded; however, drainage patterns will not change from historic locations. The drainage basins under the proposed conditions are similar to the existing basins. The majority of improvements will occur on the southern portion of the site. Stormwater runoff will be routed around the proposed structures via earthen swales. Basin characteristics and runoff for the proposed development are tabulated in Table 3 and Table 4 below. Complete drainage calculations are included in Appendix A. The northwest portion of the site that drains west to the adjacent lot is not affected by any proposed construction. The grading and addition of the proposed structures will cause a minor increase in the amount of runoff with respect to existing conditions, and the proposed detention pond will detain this increase and release it in an historic condition. Table 3. Proposed Basin BASIN AREA (acre) CN Tc (min) PR -1 15.0 72 46 Table 4. Proposed Basin Run BASIN 25 -YR PEAK FLOW (cfs) 100 -YR PEAK FLOW (cfs) 100 -YR EXCESS VOLUME (cu. ft.) PR 1 2.75 4.82 7671 V. Detention Pond A proposed detention pond will be constructed on the southem portion of the site. The pond and outlet control structure was designed to release at the historic 25 -year and 100 -year discharge rates for the entire site. The outlet control structure consists of a stand pipe with Page 4 multiple perforations designed to release at the historic 25 -year discharge rate. There is an orifice plate on top of the standpipe sized to release at the historic 100 -year discharge rate. The detention pond 25 -year storage volume is 6,425 cubic feet and the 100 -year storage volume is 8,877 cubic feet. Calculations for the proposed pond are included in the appendix of this report. VI. Results and Recommendations This proposed development has a net increase in runoff, due to the increase in total impervious area. Table 2 indicates the runoff volume associated with the existing basin. Table 4 indicates the excess runoff volume associated with the proposed basin. As indicated in the tables, the 100 year peak flow under the existing conditions is 2.41 cubic feet per second and the total post development 100 year peak flow is 4.82 cubic feet per second. This is a total increase of 2.41 cubic feet per second which will be attenuated to historic release rates. VII. Design Features Site grading will include the construction of drainage swales as needed to direct runoff towards the detention pond. The geotechnical engineer will be responsible for any foundation drain system that will be required and any subsequent dry well needed for these drain systems. VIII. Summary The proposed development at the Elder Property is minor with regard to the drainage impacts. The impact of the development increases the amount of runoff volume and peak discharge generated from the site. The increase in discharge will be contained by the proposed detention pond. The change in flow characteristics is minor and will not adversely affect any downstream landowner or structures. Water quality issues are of little concern as the majority of the runoff within the improved areas is being routed to the detention pond. Those areas that will directly discharge offsite are unimproved. Page 5 IX. References National Oceanic and Atmospheric Administration: Precipitation -Frequency Atlas of the Western United States, Volume III -Colorado. Silver Springs, MD 1973. United States Department of Agriculture, Soil Conservation Service: Soil Survey of Aspen - Gypsum Area, Colorado, Parts of Eagle, Garfield, and GARFIELD Counties, May 1992. United States Department of Agriculture, Soil Conservation Service: Urban Hydrology for Small Watersheds, June 1986. Soil Conservation Service (SCS) publication "Procedures for Determining Peak Flows in Colorado" (1980) Page 6 ELDER PROPERTY GARFIELD COUNTY, COLORADO APPENDIX A 12 L tx rt „: A HIGH COUNTRY ENGINEERING, INC. HCE1 1�! .'IvECty\ 14 INVERNESS 130112 ONE ((303))EVE 9255--054412 FM (303)09525-0547 1517 BLAKE PHOONEU(970) 945-8878 wFUX (970) 945-255501 www.hcan .com ED ELDER GARFIELD COUNTY, COLORADO ELDER PROPERTY drown by scale: checked by, date: Project No: = 2000' 2051062 VICINITY MAP 1/6/06 page: fila: �. /sdskproj/205/1044/dwg/vic map.dwg BENCHES, AND SIDES OF VALLEYS. FEET. THE AVERAGE ANNUAL NCHES. THIS UNIT IS ABOUT 90 PERCENT LLUVIAL SOILS. THE BEDROCK MATERIAL IS MODERATELY STEEP TO VERY STEEP ROM 15 TO 70%. THIS UNIT IS ABOUT 10 .,K. ii 1 11 11 11 11 11 QF'2411 ?44HR°PRECIPITATION IN ' Nike'', � HIGH COUNTRY ENGINEERING, INC. ate,^ _w Na.k• HCE ti ; "NEEFo 14 INVERNESS DRIVE ONE (3053)E X25-05441�FAX 003)) 9925-00547BIGLEF1000, CO 60112 1317 BLAKE01 (970) 9145-8675 �0 970) G45-2555 a'**•hcen4aa^ EAGLE COUNTY, COLORADO SOLARA PRESCHOOL EXHIBIT /4 NOAA MAP 2—YR, 241 -IR o: 2051062.00 x 051" file: 3 /sMprol/20.5/205, 062/N0M-2H, Prepared bysU S 1 NationolOceanica National weather, :IPITATION Pre red;fortU.S.. �scry*tion HIGH COUNTRY ENGINEERING, INC. 14 INVERNESSH NE (303)E925 95DRIVE MST, S1E 441AX (3PW)) 925-0547 15171517 9L/JO:PAONE (970) 945-9976 NFAX (970) 915-2555 wwwAmng.wom EAGLE COUNTY, COLORADO SOLARA PRESCHOOL EXHIBIT g5 NOAA MAP 25 -YR, 2411R dra JJL scale: checked Ey: REV/ Protect No: date: page: 1-12-06 6 1' ® 40,000' 2051062 x 0517 file: r./•dalmrel/205/2051062/a+9MoA,(-25ne HIGH COUNTRY ENGINEERING, INC. 14 WVFRNEPHONE (3033j)E92DRIVE EAST, � 441 FAX (331925-0547 5-0547e01f4 1317 Bl/JO=PHONE (970) 9145--587 (303)(970) 915-25555 mww.hcengaan EAGLE COUNTY, COLORADO SOLARA PRESCHOOL EXHIBIT /5 NOAA MAP 100 -Th, 241 -IR drawn by. checked by. REW date: 1-12-08 roject No: 2051062 7 ELDER PROPERTY GARFIELD COUNTY, COLORADO APPENDIX B Elder Property HOE No. 2051062.00 By: JJL Date: 1/12/06 EX25.txt TR -55 Tabular Hydrograph Input Summary Description PARCEL B, ELDER PROPERTY-25yr Rainfall Distribution Ia/P Interpolation Total Area Peak Time Peak Flow Given Input Data: Method Type II on 15.0000 ac 780.0000 min 1.1951 cfs Subarea D/S Subareas Area Description (ac) CN Tc Tt Rainfall (min) (min) (in) EX -1 Support Data: Subarea Name: EX -1, Row: 1 Sheet Flow 15.0000 Description Manning's n Flow Length Two Yr, 24 hr Rainfall Land Slope Computed Sheet flow time Shallow Concentrated Flow 67 48.7620 0.1500 300.0000 ft 1.0000 in 0.0147 ft/ft > 47.7420 min 0.0000 2.2000 Description Surface Unpaved Flow Length 120.0000 ft Watercourse Slope 0.0147 ft/ft velocity 1.9562 fps Computed Shallow flow time > 1.0200 min Total Time of Concentration > 48.7620 min ****************•************ Page 1 Elder Property HCE NO. 2051062.00 By: JJL Date: 1/12/06 EX100.tXt TR -55 Tabular Hydrograph Input Summary Description PARCEL B, ELDER PROPERTY-100yr Rainfall Distribution Ia/P Interpolation Total Area Peak Time Peak Flow Given Input Data: Method Type II On 15.0000 ac 768.0000 min 2.4113 cfs subarea D/S subareas Area Description (ac) CN TC (min) Tt Rainfall (min) (in) EX -1 Support Data: subarea Name: Ex -1, Row: 1 Sheet Flow 15.0000 Description Manning's n Flow Length Two Yr, 24 hr Rainfall Land Slope Computed Sheet flow time Shallow concentrated Flow 67 53.7900 0.1700 300.0000 ft 1.0000 in 0.0147 ft/ft > 52.7700 min Description Surface Flow Length Watercourse Slope Velocity Computed Shallow flow time 0.0000 2.6000 Unpaved 120.0000 ft 0.0147 ft/ft 1.9562 fps > 1.0200 min *************************** Total Time of concentration > 53.7900 min **************************** Page 1 Elder Property HCE No. 2051062.00 By: JJL Date: 1/12/06 TR -55 Tabular Hydrograph Method Input Summary Description PARCEL 8, ELDER PROPERTY-25yr Rainfall Distribution Ia/P Interpolation Total Area PR25.txt Peak Time Peak Flow Given Input Data: Type II On 15.0000 ac 762.0000 min 2.7451 cfs Subarea D/S Subareas Area Description (ac) CN Tc (min) Tt Rainfall (min) (in) PR -1 Support Data: Subarea Name: PR -1, Row: 1 Sheet Flow 15.0000 Description Manning's n Flow Length Two Yr, 24 hr Rainfall Land Slope Computed Sheet flow time Shallow Concentrated Flow 72 45.6720 0.1500 300.0000 ft 1.0000 in 0.0173 ft/ft > 44.7300 min 0.0000 2.2000 Description Surface Unpaved Flow Length 120.0000 ft Watercourse Slope 0.0173 ft/ft Velocity 2.1222 fps Computed Shallow flow time > 0.9420 min *************************** Total Time of Concentration > 45.6720 min **************************** composite Runoff Curve Number Calculator Description Area (ac) Curve Number BUILDING TRUCK PARK GRAVEL LOT Total Area 0.2570 2.1592 3.8908 8.6929 > 15.0000 Page 1 98 67 85 67 72 < Weighted CN Elder Property HCE No. 2051062.00 By: JJL Date: 1/12/06 PR100.txt TR -55 Tabular Hydrograph Method input Summary Description PARCEL B, ELDER PROPERTY-100yr Rainfall Distribution Ia/P Interpolation Total Area Peak Time Peak Flow Given Input Data: Type II on 15.0000 ac 762.0000 min 4.8246 cfs subarea D/s Subareas Area Description (ac) CN TC (min) Tt Rainfall (min) (in) PR -1 Support Data: Subarea Name: PR -1, Row: 1 Sheet Flow 15.0000 Description Manning's n Flow Length Two Yr, 24 hr Rainfall Land Slope Computed sheet flow time Shallow Concentrated Flow 72 45.6720 0.1500 300.0000 ft 1.0000 in 0.0173 ft/ft > 44.7300 min 0.0000 2.6000 Description Surface Unpaved Flow Length 120.0000 ft Watercourse slope 0.0173 ft/ft Velocitys Computedhallow flow time 2 1222 >fP0.9420 min *************************** Total Time of Concentration > 45.6720 min **************************** Composite Runoff Curve Number Calculator Description Area (ac) BUILDING TRUCK PARK GRAVEL LOT Total Area 0.2570 2.1592 3.8908 8.6929 > 15.0000 Curve Number Page 1 98 67 85 67 72 < weighted CN Elder Property HCE No. 2051062.00 By: 33L Date: 1/12/06 Pond Name pond25.txt Basin Output Distribution Type Type II Frequency Type 25 years Area 15.0000 ac Peak Inflow 2.7451 cfs Peak outflow 1.1900 cfs Runoff 0.3872 in Runoff Volume 21081.7216 ft3 storage Volume 6425.5051 ft3 Maximum storage Elevation 0.0000 ft Page 1 Elder Property HCE No. 2051062.00 By: JJL Date: 1/12/06 Pond Name pond100.txt Basin Output Distribution Type Type II Frequency Type 100 years Area 15.0000 ac Peak Inflow 4.8246 cfs Peak Outflow 2.4113 cfs Runoff 0.5895 in Runoff Volume 32096.2678 ft3 Storage volume 8877.2331 ft3 Maximum Storage Elevation 0.0000 ft Page 1 32 55—Potts loam, 3 to 6 percent slopes. This deep, well drained, moderately sloping soil is on mesas, bench- es, and sides of valleys. Elevation ranges from 5,000 to 7,000 feet. This soil formed in alluvium derived from sandstone, shale, or basalt. The average annual precipi- tation is about 14 inches, the average annual air tem- perature is about 46 degrees F, and the average frost - free period is about 120 days. Typically, the surface layer is brown loam about 4 inches thick. The subsoil is reddish brown clay loam about 24 inches thick. The substratum is pinkish white loam to a depth of 60 inches. Included with this soil in mapping are small areas of Olney, Kim, and Ildefonso soils that have slopes of 3 to 6 percent. These areas make up 10 to 15 percent of the map unit. Permeability is moderate, and available water capacity is high. Effective rooting depth is 60 inches or more. Surface runoff is slow, and the erosion hazard is moder- ate. This soil is used mainly for irrigated crops and hay and for dryland farming (fig. 10). Alfalfa, small grains, and grass -legume hay are grown. Small areas are used for grazing. These soils are usually irrigated by flooding. Drop structures ,in irrigation ditches, grassed waterways, and minimum tillage prevent serious erosion. Irrigation water should be carefully managed to avoid piping and erosion. Cover crops or stubble mulching also help to limit ero- sion in dryfarmed areas. The native vegetation on this soil is mainly wheat - grass, needleandthread, and sagebrush. When range condition deteriorates, forbs and shrubs increase. When the range is in poor condition, undesira- ble weeds and annual plants are numerous. Properly managing grazing maintains and improves range condi- tion. Reducing brush improves the range. Seeding im- proves range in poor condition. Crested wheatgrass, western wheatgrass, and Russian wildrye are suitable for seeding. Preparing a seedbed and drilling the seed are good practices. Pheasant, mourning dove, cottontail rabbit, some mule deer, and squirrel find habitat on this soil. Community development and recreation are limited by low strength and the shrink -swell potential. Dwellings and roads can be designed to overcome these limita- tions. Community sewage systems will be needed if the population density increases. This soil is in capability subclasses Ille, irrigated, and IVe, nonirrigated. 56—Potts loam, 6 to 12 percent slopes. This deep, well drained, moderately sloping to rolling soil is on mesas, benches, and sides of valleys. Elevation ranges from 5,000 to 7,000 feet. This soil formed in alluvium derived from sandstone, shale, or basalt. The average annual precipitation is about 14 inches, the average SOIL SURVEY annual air temperature is about 46 degrees F, and the average frost -free period is about 120 days. Typically, the surface layer is brown loam about 4 inches thick. The subsoil is reddish brown clay loam about 24 inches thick. The substratum is pinkish white loam to a depth of 60 inches. Included with this soil in mapping are small areas of Kim, Olney, and Ildefonso soils that have slopes of 6 to 12 percent. These areas make up 10 to 15 percent of the map unit. Permeability is moderate, and available water capacity is high. Effective rooting depth is 60 inches or more. Surface runoff is medium, and the erosion hazard is severe. This soil is used mainly for grazing, wildlife habitat, and some dryland farming (fig. 10). Wheat, barley, and oats are grown. Minimum contour tillage and stubble mulching help tc prevent excessive erosion. The native vegetation on this soil is mainly wheat grass, needleandthread, and sagebrush. When range condition deteriorates, forbs and shrub: increase. When the range is in poor condition, undesira ble weeds and annual plants are numerous. Properh managing grazing improves and maintains range condi tion. Reducing brush improves range. Seeding improve range in poor condition. Crested wheatgrass, westen wheatgrass, and Russian wildrye are suitable for seed ing. Preparing a seedbed and drilling the seed are goo practices. Community development and recreation are limited b low strength, shrink -swell potential, and slope. Dwelling and roads can be designed to overcome these limits tions. Community sewage systems will be needed if th population density increases. This soil isin capability subclass IVe, irrigated an nonirrigated. 57—Potts-Ildefonso complex, 3 to 12 percer slopes. Theso-.gently sloping to rolling soils are c mesas and sides of valleys. Elevation ranges from 5,0C to 6,500 feet. The Potts soil formed in alluvium derive from sandstone, shale, or basalt. The Ildefonso sr formed in very "strongly calcareous, basaltic alluvium ar small amounts of eolian material. The average annu precipitation is about 14 inches, the average annual r temperature is about 46 degrees F, and the avera frost -free period is about 120 days. The Potts soil makes up about 60 percent of the m; unit, and the Ildefonso sods makes up about 30 perces The Potts soil is on slightly concave positions, and t Ildefonso soil is on the breaks of steeper slopes. The Potts soil is deep and well drained. Typically, t surface layer is brown loam about 4 inches thick. T subsoil is reddish brown clay loam about 24 inches this The substratum is pinkish white loam that extends tc depth of 60 inches. RIFLE AREA, COLORADO 66—Torrlorthents-Camborthids-Rock outcrop com- plex, steep. This broadly defined unit consists of ex- posed sandstone and shale bedrock, loose stones, and soils that are shallow to deep over sandstone and shale bedrock and stony basaltic alluvium. This complex occurs throughout the survey area. The soils and out- crops are moderately steep to very steep. Slope ranges from 15 to 70 percent. Torriorthents make up about 45 percent of the com- plex, Camborthids make up 20 percent, and Rock out- crop makes up 15 percent. The Torriorthents are on foothills and mountainsides below Rock outcrop. The moderately steep Camborthids are on lower toe slopes and concave open areas on foothills and mountainsides. Torriorthents are shallow to moderately deep. They are generally clayey to loamy and contain variable amounts of gravel, cobbles, and stones. The surface is normally covered with stones weathered from the higher - lying Rock outcrop. South of the Colorado River, basaltic stones and cobbles are on the surface. Camborthids are shallow to deep. They are generally clayey to loamy and have slightly more clay in the sub- soil than in the surface layer. The surface layer is light colored. The profile is normally free of stones, but scat- tered basalt stones, cobbles, and sandstone fragments are on the surfjce. The Rock outcrop is mainly Mesa Verde sandstone and Wasatch shale. Some areas are covered with basal- tic boulders and stones. Small areas of limestone out- crops and exposed gypsum are in the eastern part of the survey area. Included in mapping are small, isolated areas of lide- fonso, Lazear, Ansari, Begay, Heldt, and Dollard soils. These intermittent areas make up 10 to 20 percent of this map unit. This complex is used for grazing, wildlife habitat, and recreation. The stones on the surface and the steep slopes make Ibis complex unsuitable for crops. Some areas can be ;reseeded to pasture by broadcast seeding. Other plant- teg.methods are made difficult by the stones and slopes. ,The native vegetation includes wheatgrasses, blue - asses, Indian ricegrass, needlegrasses, bitterbrush, ountainmahogany, sagebrush, and an overstory of Tryon and juniper. ;The value of grazing is fair. The vegetation should be anaged to maintain wood production and limited graz- -.Selectively thinning the pinyon and juniper improves mg and provides firewood and posts. Steep slopes, crate to severe erosion hazard, and slow regrowth Res affect harvesting and management. ost of this complex is a prime wintering area for ::'Rabbits, coyote, and a few elk also find food and er,on this complex. o°Iding is limited by steep slopes and stoniness. limitations can be overcome by appropriate and construction. 37 This complex is in capability subclass Vile, nonirrigat- ed. 67—Torriorthents-Rock outcrop complex, steep. This broadly defined unit consists of exposed sandstone and shale bedrock and stony soils that are shallow to moderately deep over sandstone and shale and stony basaltic alluvium. Areas of this complex occur throughout the survey area. The soils and outcrops are moderately steep to very steep. Slope ranges from 15 to 70 percent. Torriorthents make up about 60 percent of this com- plex, and Rock outcrop makes up 25 percent. The Tor- riorthents are on foothills and mountainsides below the Rock outcrop. Torriorthents are generally clayey to loamy and con- tain variable amounts of gravel, cobbles, and stones. The surface is normally covered with stones weathered from the higher -lying .Rock outcrop. South of the Colora- do River, stones and cobbles of basalt are on the sur- face. The Rock outcrop is mainly Mesa Verde sandstone and Wasatch shale. Some areas are covered with basal- tic boulders and stones. Small areas of limestone out- crops and exposed gypsum are in the eastern part of the survey area. Included in mapping are small isolated areas of Ilde- fonso, Lazear, Ansari, Gaynor, Tridell, and Nihill soils. These intermittent areas make up 10 to 15 percent of this map unit This complex is used for limited grazing, wildlife habi- tat, and recreation. Because of the stones on the surface, the Rock out- crop, and the steep slope, this complex is unsuited to crops. The native vegetation includes wheatgrass, bluegrass, Indian ricegrass,'-needlegrass, bitterbrush, sagebrush, mountainmahogany and an overstory of pinyon and juni- per. The vegetation should be managed to maintain wood production and limited grazing. Selectively thinning the pinyon and juniper improves grazing_ and provides fire- wood and posts–Steep slopes, moderate to severe ero- sion hazard, and slow regrowth of trees affect harvesting and management:, Most of this complex is a prime wintering area for deer. Rabbits, coyote, and a few elk also find food and cover on this complex. Community development is limited by the Rock out- crop, steep slopes, and stoniness. These limitations can be overcome by appropriate design and construction. This complex is in capability subclass Vile, nonirrigat- ed. 68—Vale silt loam, 3 to 6 percent slopes. This deep, well drained, gently sloping soil is on mesas, terraces, and alluvial fans. Elevation ranges from 5,000 to 7,200 feet. This soil formed in calcareous eolian material. The IFLE AREA, COLORADO a c N N Y C 1.) N O C 0 NA N L Y 111 w 0 O 10 0. 43 a N as 4) N N 0 c N N 0 Y +) 10 N L L W d a 3 3 11 0 0 0 0 £ -) -1 £ 1 1 1 N 1 1 a 1 1 N 1 1 S L S S N CO m m m a 0 x x z x £ 3 3 3 O 0 0 J -1 J Moderate 1 1 1 1 N W N 4 1 (0 a a 1 1 A A RI 1 1 L L L S S O a) a) 40 be a a 0 0 0 0 2 S £ £ £ 3 3 0 0 J -1 Moderate Moderate. W 1 1 1 Y 1 1 1 10 1 1 1- a) O) S COL O M m O £ x 2 = Moderate Moderate- 3 0 J oderate--- 0 .J Moderate--- Moderate--- Moderate--- Moderate--- Moderate--- Moderate--- O -1 3 3 O O -1 J Moderate--- 0) a• a) N N 'y n .0 1 4 0 N N 1 1 10 O. 0. 1 1 0. 0. 0. a 0: 0: 0 0 0 0 0 0 0 0 0 0 0 0 0 •o 0 ? > '.0 0 0 o 1/40 '0 •O •O •D •O •O '0 1 •O 1 1 1 •D •O •D 1 A n n n n n n 0 n 0 0 0 n n n 0 7 0) 04 s 0 3 S0 6 Y O 0 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 n w •0 •O •D 10 0 •D 10 .o .o CO .0 •o •D •o .o •O .O Z x 0 n n n n n n A n n n n n ro a J V 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1(\ W '3 4 1 •• - 1 I I 1 1 1 I 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 4 N 0) 0 C O 0 z z W N N C O 0 0 z z z 0 0) N N 01 C C C C t 0 0 0 0 0 Z z z z z ry 01 C C Z O O) 0) 0 0) 4) C C 0 0 0 0 0 Z 2 - 2 2 2 011 10 V [O in 10 0) m 10 m CO m m CO CO CO 0 c CU 0 0 CD E .0 N >) C N 0. co o In N rt 0 N 10 o > > •L O * 0 in _1 x£ 10£ S S s 10 O 10 4) rn0 S N N a Y 3 3 S 0 0 0 01 N N C L •• L 0 N * CO C N0. 1na a N N 0' N O NCA N * 0 O. Ildefonso D C 0 0 Torriorthents. 147 See footnote at end of table. 148 SOIL SURVEY Camborthids. Rock outcrop. Rock outcrop. 3 3 3 3 O 0 0 0 -1 .] -1 J d 1 1 Y 1 1 co 1 1 L 1 4) L L L 0 W M M O z = x x Moderate -- Moderate -- x 0 o 0 0 <o e A. N n i y 1 y. • 1 1 .. 1 0. y c. 0 z z m Occasional N > O 0 1- 0 0 . ON CO N b W N 41 C N ••N N C N i ..1 0 N '0 �> N N 3 I` 1- V C_ 0. CO E N 0 O 0 O 4, N L v N 0 N L CO 0.0 L. O N v .0 a c m 0 Y N O 0. E 0 00 w N 0. N E 0.) .0 CIA 0 0 0 Y 0. L O N N •0 N N 1n MINIMUM POND VOLUME Pett ELDER PROPERTY FILE: PONDVOLUME.XLS HCE Job Number: 2051062.00 CALCS BY: DJD CHECKED BY: REW Date: 1-11-06 PROPOSED DETENTION POND ELEVATION AREA VOLUME (Ft3) CUMULATIVE VOLUME (Ft3) 5624.00 0.00 0.00 0.00 5625.00 2,331.00 1,165.50 1,165.50 5626.00 4,919.00 3,625.00 4,790.50 5627.00 8,144.00 6,531.50 11,322.00 5628.00 12,007.00 10,075.50 21,397.50 TOTAL 25 -YR VOLUME (ft3) = 6,425.0 WSEL = ogoaa 'a F� TOTAL 100 -YR VOLUME (ft3) = 8,877.0 WSEL = 1028 DETENTION POND SUMMARY ELDER PROPERTY JOB # 2051062.00 1/11/2006 CALCED BY: DJD CHECKED BY: REW BOTTOM OF POND = 5624.0' 25 -YR = 5626.25' 100 -YR = 5626.63' 25 -YEAR RISER PIPE 25 -YEAR HISTORIC RELEASE RATE = 1.19 CFS DIAMETER OF HOLES = 1.0 INCH NUMVER OF HOLES PER LAYER = 8 NUMBER OF LAYERS = 4 VERTICAL DISTANCE BETWEEN LAYERS = 4 INCHES 100 -YEAR HORIZONTAL ORIFICE 100 -YEAR HISTORIC RELEASE RATE = 2.4 CFS DIAMETER OF OPENING = 18 INCHES ELEVATION AT TOP OF PIPE = 5626.63' ELEVATION OF WATER, PER UDFCD = 5626.93' DETERMINE THE DIMENSIONS OF THE EMERGENCY SPILLWAY: THE TOTAL 100 -YEAR INFLOW = 4.82 cfs L = QWEIR / (CH312) L = 4.82 / (3.4) (.5)3/2 L=4.Oft Flow Capacity of a Riser (Inlet Control) Project: - - ----- ELDERPROPERTY Basin ID: Layer 4 Layer 3 Layer 2 Layer 1 Design Information (Inputj: Diameter of holes Number of holes per layer Number of layers Vertical distance between layers Orifice discharge coefficient Total opening area at each layer PROPOSED: DETENTION POND; 25YEAR--- - - -- - )000000 )00000C �00000C )000000 yd NumherefMlee ineachlaler d ='c'. 1'.[000 in. n= 8 NL= 4 h = 400in. Co= 0165 A. = 62832 sq in Ao = 00436k sq ft Calculation of Collection Capacity : The starting water surface elevation must be Xhe central elevation of the first layer. Enter water surface elevations in ascending order. start Water Surface Elevation ft (input) Central Elevations of Layers of Holes in feet Layerl Layer2 Layer3 Layer4 Layer5 Layer Layer7 Layer8 Layer9 Layer 10 0.00 17.0.33 I I I I I .. • 0.67 I 1,00 I Collection Capacity for Each Layer of Holes in cfs 0:00 025 0.11 0.00 0.00 0.00 0,00 0.00 Flow Rate cfs 0:50 0.16 0.09 0.00 • 0€00 0.00'. • 0.11 0:75 00 1:25 0.20 023 0.25 0.15 0.19 0.22 0.06 0.13 • 0.17 0,00 000' 0.111' 0.25 0.41' 0.54 1:50 1.75 a. 28 0,30 0.25 0.27 2.00 2.25 2.50 2,75 3.00 3:25 350 0.32 0.34 0.36 0.38 0.39 041 0.43 3:75 0.29 0.32 • 0.34 0.35 0.37 • 0.39 0,41 0.42 0.21 0.24 0.26 0,29 0.31 0,33 035 0.37 0.38 0,40 0.16 0.20 0,23, 0.25 0;28 0.30 0.32 0.34 0:36' 0:38;' 0.76 • 0.89 4 00 425 0.46 0.44 0.42 0.39 1.01 1.1[ 1.20 1.28 1.36 1,44: 1.51 1.57' 1.64 0.47 0,45 0.43 0.41 1.70 _...;,1.76x: UD-Detention_v1.03a.xls, Riser 1/12/2006, 8:38 PM ollection Capacity of Horizontal Orifice (Inlet Control) Project: ELDER PROPERTY Basin ID: PROPOSED DETENTION POND,'10AYR outlet 'frustum fl Culvert circular opening area and perimeter Design Information (Input): Circular Opening: OR Rectangular Opening: box opening area and perimeter Diameter Culvert Dia. = 1°50 ft. Width W = ft. Length L=.__._.___..ft. Percentage of Open Area After Trash Rack Reduction % open = 80,00 % Orifice Coefficient Co = 0,65 Weir Coefficient Cw = 3.10 Orifice Elevation Eo = : :5626;63 ft. Calculation of Collection Capacity: Net Opening Area (after Trash Rack Reduction) Perimeter as Weir Length Enter water surface elevations in ascending order. Ao = 1.41'1 sq. ft. Lw = 0i4g1r ft. start Water Surface Elevation ft (input) 5626.63 Weir Flow cfs (output) Orifice Flow cfs (output) Collection Capacity cfs (output) 0;00 5626:65 0.04 5626.70 0,27 5626.75 0.6 5626.80 5626.85 626S0 5626..91 5626.92 1 02 1151 2:05 2:16 22& 5626.93f 2:41 0.00 1.04 1.95 2.55 3.04 3.46 3.83 3.30 0.001' a04 0.27 0.61 1.02;1 1,51 2.05: 216: 3.97 2.281. 4.04 2.401: UD-Detention_v1.03a.xls, Horizontal Or 1/12/2006, 8:46 PM PROPOSED DETENTION POND RISER FLOW ALLOWED = 1.19 cfs STAND PIPE DIAMETER SIZE = 18" STAND PIPE HOLE DIAMETER = 1.0" ROW SPACING = 4" NUMBER OF ROWS = 4 NUMBER OF COLUMNS = 8 ORIFICE FLOW ALLOWED = 2.4 cfs MAXIMUM EMERGENCY WEIR FLOW = 4.82 cfs FLOW TOP OF POND EL= SEE CONSTRUCTION DRAWINGS HONEYCOMB GRATE ORIFICE PLATE MAXIMUM WATER SEE PLAN SHTS 18"0 CMP RISER 18"4 ADS—N12 (SEE GRADING PLAN FOR INVERTS AND PIPE LENGTHS) POND OUTFLOW CONTROL DETAIL N.T.S. HIGH COUNTRY ENGINEERING, INC. 14 INVERNESS DRIVE EAST, SIE F•120, ENGLEWOOD, CO 80112 PHONE 13031 925.0544 FAX 490819250547 1517 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS. CO 81601 PHONE (970)9458576 FAX (570)0452655 W W W.HCENO.COM ED ELDER RIFLE, CO ELDER PROPERTY DETAIL DETENTION POND OUTLET STRUCTURE DRAWN BY: DJD BOTTOM OF POND SEE PLAN SHTS SCALE: NTS CHECKED BY: REW PROJECT NO: 2051062.00 DATE: 1-12-06 PAGE: J:/5DsKPROJ/205/ 1 062/DET-ST.DWG I1 II I1 II II, II II II IIS II II IIS IX III 111 1I A -MINIMUM OF 12.0 FOOT WIDE ACCESS FROM R.O.W. TO THE DETENTION BASIN 15 REQUIRED irDETENTION/RETENTION BASIN TRACT BOUNDARY 5, BERM TOP WIDTH SHALL BE AT LEAST AS WIDE A5 THE BASIN IS I DEEP, 5' MIN. _IA GRATE OR ROAD 0.0' MIN. EXIST. GROUND PROFILE \t- 100 YR W.S. DETENTION/RETENTION TRACT BOUNDARY SHALL BE AT LEAST 3.0 FEET BEYOND TOP OF EXCAVATED BASIN OR TOE OF BERM. PLAN VIEW NTS PROPOSED GRADE OL zz SECTION A -A NTS STEEPEST 5t: 4H:IV FOR BASINS ON PUBLIC LANDS AND PARKS 3H:1V FOR SEEDED OR SODDED SLOPES 2H:1V FOR RIPRAP OR OTHER APPROVED SLOPE PROTECTION VERTICAL WALLS WITH SAFETY RAILING LIMITED TO ONE SIDE ONLY WHERE APPROVED BY THE CITY ENGINEER OR COUNTY DEVELOPMENT ENGINEER STEEPEST 52: 6H:1V FOR ACCESS RAMP, ALL SURFACES MINIMUM 55: 0.5% FOR CONCRETE CHANNEL 1.0X FOR ASPHALT (PARKING LOT) 2.0% FOR ALL OTHER SURFACES MAXIMUM D: 4' RETENTION BASIN 8' WET OR DRY DETENTION FACILITY >8' SPECIAL APPROVAL REQUIRED, BUT MAY BE ALLOWED FOR MULTIPLE USE PONDS OR FOR STEEP TERRAINS MINIMUM D: 4' WET PONDS (SEE PAGE VIII -1) DETENTION BASIN GEOMETRIC REQUIREMENTS FIGURE N-3 DECEMBER 1994 N-11 HIGH COUNTRY ENGINEERING, INC. 14 INVERNESS DRIVE EAST, STE F-120, ENGLEWOOD, CO 80112 PHONE (303) 9250544 FAX (303) 9250547 1517 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS. CO 81801 PHONE 197019458876 FAX (970)94E92555 W W W.HCENG.COM ED ELDER RIFLE. CO ELDER PROPERTY DETAIL DETENNON POND DRAWN BY: DJD SCALE NTS CHECKED BY: REW PROJECT NO: 2051062.00 DATE: 1-12-06 PAGE FILE: J:/SDSKPROJ/205/1062/DET-ST.DWG 1 11 11 II 11 II II II 11 II II II 11 11 II 11 11 FLARED END SECTIONS 4 RIGHT SIDE VI 0 2 0 W Z WW Z 1L OZ OO wF 5La m a 0 wa Z M O 0 LI- Z 43 0 0 01 0 OO d, D W I ^I 0 Opp ....t.. -.; W vi o 0 0 z NOTE: ALL DIMENSIONS ARE NOMINAL HIGH COUNTRY ENGINEERING, INC. 14 INVERNESS DRIVE EAST, STE F-120, ENGLEWOOD, CO 80112 PHONE (303) 0280544 FAX 1503) 8250547 1817 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS, C081801 PHONE (97019438678 FAX (87010452555 W W W.MCENG.COM ED ELDER RIFLE, CO ELDER PROPERTY DETAIL FLARED END SECTION DRAWN BY: DJD SCALE: NTS CHECKED BY. REW PROJECT NO: 2051062.00 DATE: PAGE 1-12-06 FILE: J: /SDSKPROJ/205/ 1062/D EJ-ST.DW G 29.00 in (737 mm) 29.00 in (737 mm) 35.00 in (889 mm) 45.00 in (1143 mm) 63.00 in (1600 mm) 63.00 in (1600 mm) L 25.00 in (635 mm) 25.00 in (635mm)1 32.00 in (813 mrn) 36.00 in (914 mm) 58.00 in (1473 mm) 58.00 in (1473 mrn) 6.50 in (165 mm) ttoo to CO CI) 6.50 in (165 mm) 6.50 in (165 mm) Co u> 06 N. 8.60 in (218 mm) 1. CO 10.00 in (254 mm) 10.00 in (254 Jr m) 15.00 in (381 mm) 18.00 in (457 rrm) 12.00 in (305 mm) 25.00 in (635 mrn) Q cE i tO CO t0 6.50 in (165 mm) � EE t� t` cT 7.50 in (191 mm) ILC r aJ cE LO lc a) W `'C \I co 15 in (375 mm) 18 in (450 mm) 24 in (600 rnm) 30 in (750 mm) M 0 0) PART # o N 1510NP 0 o7; r Q f N to p C) to ��`pp- 2 0 W Z WW Z 1L OZ OO wF 5La m a 0 wa Z M O 0 LI- Z 43 0 0 01 0 OO d, D W I ^I 0 Opp ....t.. -.; W vi o 0 0 z NOTE: ALL DIMENSIONS ARE NOMINAL HIGH COUNTRY ENGINEERING, INC. 14 INVERNESS DRIVE EAST, STE F-120, ENGLEWOOD, CO 80112 PHONE (303) 0280544 FAX 1503) 8250547 1817 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS, C081801 PHONE (97019438678 FAX (87010452555 W W W.MCENG.COM ED ELDER RIFLE, CO ELDER PROPERTY DETAIL FLARED END SECTION DRAWN BY: DJD SCALE: NTS CHECKED BY. REW PROJECT NO: 2051062.00 DATE: PAGE 1-12-06 FILE: J: /SDSKPROJ/205/ 1062/D EJ-ST.DW G