HomeMy WebLinkAbout1.16 Grading and drainage plan'''' YALERUS Grading and Drainage Plan j
Master Drainage Report for Valerus-Hunter Mesa Compressor Site South of Rifle in Garfield County, Colorado Prepared for: PVCMI 1038 County Road 323 Rifle, CO 81650 Prepared by: Sopris
Engineering, LLC 502 Main Street Suite A3 Carbondale, Colorado 81623 SE Project Number: 10090 October 5,2010 SOPRIS ENGINEERING • lle civil consultants 502 Main Street Suite A3 Carbondale
Colorado 81623 (970)704-0311 Fax:(970)704-0313
I Master Drainage Report -Valerus· Hunter Mesa Compressor. SE Project No. 10090 Table of Contents I. Introduction A. Project Overview B. Property Location C. Site Description II. Analysis
Methods and Assumptions III. Drainage System Description A. Existing Offsite Drainage Conditions B. Existing Onsite Drainage Conditions C. Proposed Drainage System Description D. Stormwater
Detention E. Drainage Facility Maintenance IV. Conclusions V. References Appendix A Appendix B Appendix C Appendices NRCS Soils Map Existing Drainage Calculations Developed Drainage
Calculations Exhibits Existing Drainage Basin Exhibit October 5,2010 I Exhibit 1 Exhibit 2 Post Development Drainage Basin Exhibit SOPRIS ENGINEERING • ltC civil consultants 502 Main
Street Suite A3 Car jale, Colorado 81623 (970)704·0311 ax: (970)704·0313
I Master Drainage Report -Valerus-Hun, . .Iesa Compressor -SE Project No. 10090 October 5,2010 I I. Introduction A. Project Overview This drainage report has been prepared as a part
of the limited impact review process for the ValerusHunter Mesa Compressor Site (VHMC). The purpose of this report is to design and quantify the necessary storm drainage improvements
associated with this project. This report presents our findings and recommendations for stormwater mitigation associated with the site improvements of the project. Our evaluation and
studies are based on the Garfield County Land Use Code, Sections 7-205 through 7-207 related to Erosion Control, Drainage, and Stormwater Run-Off. The VHMC project will consist of a
gravel driving surface, various buildings for compressors and equipment storage associated with compressor station activities. Sopris Engineering, LLC (SE) has analyzed the project's
impacts and has designed a drainage detention structure to release the peak flow at pre-development rates for the 2-year and 25-year 24 hour duration storm. SE also has analyzed the
offsite drainage areas that are entering this site. The appendices located in the back of this report contain all supporting calculations associated with this analysis. B. Project Location
The VHMC is located just south of the Garfield County Airport situated in Section 30 of Township 6 South, Range 92 in Garfield County, Colorado. The access road to the site is off of
County Road 333, approximately 2 miles south of Airport Road. C. Site Description The VHMC Site lies along a low lying ridge on the Hunter Mesa plateau, south of the Garfield County
Airport. The surrounding area is largely undeveloped with the exception of numerous gas drilling pads. Ground cover consists of native vegetation which consists primarily of sage brush
and grass rangeland. The basin generally drains from south to north on gentle slopes varying from 3%-15%. The soil composition onsite consists of mainly type '8' soils as defined by
the Natural Resources Conservation Service (NRCS) soil survey. Onsite soils consist of silty and rocky loams, and rock outcrops. Appendix A includes an NRCS Soils Map for this site as
well as descriptions of the soil types. II. Analysis Methods and Assumptions The peak runoff rates for the basin were analyzed for the 2-year and the 25-year storm using the Soil Conservation
Service (SCS) TR-55 method. Time of Concentration calculations were performed using the TR-55 method. Hydraulic routing of sub basins was calculated using hydrodynamic link routing.
Precipitation data for the site was taken from the NOAA atlas rainfali maps for Colorado. The area rainfall distribution is the SCS Type II for the 24-hr storm. Drainage basin soil information
was obtained from the Natural Resource Conservation Service (NRCS) soil survey. All calculations and analysis were accomplished using Storm Net software. The site is required to detain
the difference between pre and post development for the 2-year and 25-year 24 hour storm per Section 7-207(C) of the Garfield County Land Use Code. SOPRIS ENGINEERING • llC civil consultants
502 Main Street Suite A3 Carbondale, Colorado 81623 (970)704-0311 Fax: (970)704-0313
October 5, 2010 III. Drainage System Description A. Existing Off-Site Drainage Conditions The VHMC Site is located on a low lying ridge which minimizes the off-site flows entering the
site. The majority of flows generated from upstream basins are currently diverted via existing road side swales and existing natural drainage swales. The one off-site drainage basin
that conveys flows through the site was delineated based on topography generated from a recent survey of the area. Exhibit-1 illustrates the existing offsite drainage basin that contributes
flows to the site. The existing drainage basins are essentially undeveloped and consist of native vegetation which consists of sage brush rangeland. Based on the soil survey information
and on the existing vegetative cover, curve numbers were assigned to specific areas within each sub basin. The existing soils consist of type 'B' soils. For drainage calculations, it
was assumed that the majority of the existing drainage area soils and vegetative cover were in 'poor condition'. Weighted curve numbers were calculated based on the existing land use
and the underlying soil condition. The existing sub basin data and calculations for the 2-year and 25-year storms are summarized in Table A below. B. Existing Onsite Drainage Conditions
The existing onsite drainage subareas were analyzed for pre-post detention calculations. These subareas were delineated based on site topography, the limits of disturbance onsite, and
key drainage concentration points where the flows leave the site. Table A summarizes the existing onsite sub basin data and stormwater runoff flows for the 2 and 25-year storm events.
......... ~ '"'-.... .n.I~ .. ,11 "",cU"Q 'Iii' _\.IIu .. II ... IY AREA WEIGHTED TIME OF EX. 2 YR PEAK EX. 25 YR PEAK SUBBASIN ID (acres) CN CONCENTRATION (min:sec) RUNOFF (cts) RUNOFF
(cts) EX-OFFSITE 1 0.24 67.00 000:05:55 0.00 0.05 EX-ONSITE 1 0.33 67.00 000:19:59 0.00 0.05 EX-ONSITE 2 1.39 67.00 000:20:36 0.00 0.21 -------Refer to Appendix B for a summary of existing
drainage basin calculations. C. Proposed Onsite Drainage System Description The VHMC project will consist of a gravel driving surface, various buildings for compressors and equipment
storage associated with compressor station operations. Diversion ditches will be constructed to route offsite and onsite flows away from the proposed structures and to the proposed detention
facility. Curve numbers were assigned to each basin based on the developed land use and on the soil survey. Refer to Exhibit-1 for a map that illustrates the delineation of each of these
proposed post development on-site basins. Table B below summarizes the developed onsite sub basin data and calculations for the 2 and 25-year storm events. Appendix C contains supporting
calculations for the developed onsite basins. laDle tl·uevelo Dea unslte urarnaae :>ummarv AREA WEIGHTED TIMEOF DE2 YR PEAK DE 2S YR PEAK SUBBASIN ID (acres) CN CONCENTRATION RUNOFF
(cIs) RUNOFF (cIs) (min:sec) POST-ONSITE 1 0.33 80.33 000:19:59 0.04 0.24 POST-ONSITE 2 1.39 85.05 000:20:36 0.36 1.41 SOPRIS ENGINEERING • llC civil consultants 502 Main Street Suite
A3 Carl 'ale, Colorado 81623 (970)704-0311' IX: (970)704-0313
October 5,2010 D. StormWater Detention Garfield County requires that the rate of runoff from the developed site shall not exceed the existing predevelopment rate of ~unoff for the 2-year
and 25-year storm event. The peak runoffs for the existing and developed storms were compared using the SCS hydrograph method to determine the required storage volume. Using the StormNet
program, a required volume for the developed drainage sub areas was calculated and was used to size the proposed detention ponds and the outflow structures. A summary of the required
detention volume, and the attenuated peak flow leaving the site is included in Table C below. T a bl e C -R E!~Ulred Stormwater Detention Summa v EX. 25 YR REQUIRED DETENTION 25 SUBBASIN
ID PEAK RUNOFF DETENTION POND DEPTH YEAR PEAK (cfs) STORAGE {e. F.) (FT) RUNOFF (cts) POST-ONSITE 1 0.05 3' (Includes l' 0.24 2100.00 POST-ONSITE 2 0.21 of freeboard) 0.02 TOTAL 0.26
0.26 Because of the small size of the onsite drainage subareas, the developed site was examined as a whole and only one detention pond will serve the entire site. The smaller post-onsite
1 drainage area on the west side of the site will be allowed to flow offsite without any detention. Post-onsite 2, the east side drainage subarea, will flow into the detention pond along
with the offsite flow that is routed through the site. The detention pond will have one 6" pipe that will be capped with a 2" orifice hole, set with the invert l' above the bottom of
the pond, which will allow the attenuated peak flow out from the detention pond. During the developed storm event, water will pond to 1', after which the combined existing stormwater
peak runoff would flow out through 2" orifice. Because the existing 2 year storm event does not have any runoff, the 2 year developed storm event will pond in the bottom l' of the pond
without any stormwater runoff leaving the site. Storm events greater than the 25 year will over top the detention pond via a riprap weir overflow structure. Final design and details
of the detention pond are included on the site construction plans. This detention design attenuates the 2-year and 25-year storm runoff to the historic rate. Total required pond storage
capacity is equal to approximately 2,100 cubic feet. E. Drainage Facility Maintenance Stormwater maintenance tasks will include checking and cleaning out the detention pond of any debris
or sediment accumulation as well as maintaining any vegetation in conveyance swales. The detention ponds should be monitored for any sediment loading within the ponds themselves as well
as the pipe structures. Maintenance of surrounding landscapinglvegetation may also be required after major storm events. Final construction stages of work must follow a complete landscaping
and ground covering task to permanently re-vegetate and cover bare grounds that will remain open space to avoid long-term soil erosion. This effort will reduce the risk of unnecessary
clogging and failure of the drainage system. SOPRIS ENGINEERING • llC civil conSUltants 502 Main Street Suite A3 Carbondale, Colorado 81623 (970)704-0311 Fax: (970)704-0313
I Master Drainage Report -Valerus-Hunter Mesa Compressor -SE Project No. 10090 October 5, 20101 IV. Conclusions The required detention pond and the outflow pipe for the developed site
will treat the stormwater runoff and will outflow at the predevelopment rate. Sincerely, ~t~ Design Engineer SOPRIS ENGINEERING • LtC c ivil c on s ult a nts 502 M ain St ree t Suite
A3 ca ( ::Ia le , Colora do 81623 (970)704-03 11{ ax : (970 )704 · 03 1 3
I Master Drainage Report -Valerus-Hunte .,esa Compressor -SE Project No. 10090 October 5,2010 I v. References The following manuals and computer programs were used for this drainage
report: • Garfield County Land Use Code, Sections 7 -207(C) • Urban Drainage Flood Control District Manual, 2001 Edition • The NRCS Method Technical Release 55 titled, :Urban Hydrology
for Small Watersheds", dated June 1986 • Boss International StormNET Software SOPRIS ENGINEERING • lle civil consultants 502 Main Street Suite A3 Carbondale, Colorado 81623 (970)704-0311
Fax: (970)704-0313
I Master Drainage Report -Valerus-Hunter Mesa Compressor -SE Prolect No. 10090 APPENDIX A (NRCS SOILS MAP) October 5,2010 I SOPRIS ENGINEERING • lLe civil consultants 502 Main Street
Suite A3 Car dale, Colorado 81623 (970)704-0311 'ax: (970)704-0313
39" 29' 4Z' 39° 29' 34" ~ •'" 1; ~ •'" 1; N A Soil Map-Rifle Area, Colorado, Parts of Garfield and Mesa Counties (Valerus-Antero Hunter Mesa Compressor Station Site) Map Scale: 1:1,890
irprilted on A size (8.5" x 11-) sheet. o~ """~==25= ====c5~0 . .............~ ~10=0= ============1~5M0e oo~ o~ . ...... ;1~00~ ==~~==20~0 . ...........~ . ...~ 4~0=0= ====~~=========6?0F0e
el USDA Natural Resources ~ Conservation Service Web Soil Survey National Cooperative Soil Survey •'" ~ N • ~ ~ 9/23/2010 Page 1 of 3 39" 29' 43" ~ ~ 39" 29' 34"
--USDA Soil Map-Rifle Area, Colorado, Parts of Garfield and Mesa Counties (Valerus-Antero Hunter Mesa Compressor Station Site) MAP LEGEND MAP INFORMATION Area of Interest (ADI) D Area
of Interest (ACI) Soils D Soil Map Units Special Point Features '" Blowout IRI Borrow Pit * Clay Spot • Closed Depression X Gravel Pit Gravelly Spot @landfill A lava Flow .... Marsh
or swamp 1< Mine or Quarry @Miscellaneous Water ® Perennial Water v Rock Outcrop + Saline Spot · Sandy Spot Severely Eroded Spot 0) Sinkhole p Slide or Slip ;;J Sodic Spot Spoil Area
(} Stony Spot Natural Resources Conservation Service Q) Very Stony Spot t Wet Spot ... Other Special Line Features "'-Gully ... Short Steep Slope ~, Other Political Features 0 Cities
Water Features G;iI Oceans ~ Streams and Canals Transportation ~ -"'"' .~ .w-,:, ~ Rails Interstate Highways US Routes Major Roads Local Roads Web Soil Survey National Cooperative Soil
Survey Map Scale: 1:1,890 if printed on A size (8.5" )( 11 ") sheet. The soil surveys that comprise your ADI were mapped at 1 :24,000. Please rely on the bar scale on each map sheet
for accurate map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: hUp:/Iwebsoilsurvey.nrcs.usda.gov Coordinate System: UTM Zone 13N NAD83 This
product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area
Data: Version 6, Mar 25, 2008 Date(s) aerial images were photographed: 8/29/2005 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs
from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 9/23/2010 Page2of3
Soil Map-Rifle Area, Colorado, Parts of Garfield and Mesa Counties Valerus-Antero Hunter Mesa Compressor Starlon Site USDA =e= Map Unit Legend Map Unit Symbol 55 58 Totals for Area of
Interest Natural Resources Conservation Service Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map Unit Name Acres InAOI Potts loam, 3 to 6 percent slopes Potts-Ildefonso
complex, 12 to 25 percent slopes Web Soil Survey National Cooperative Soil Survey 15.6 2.9 18.5 Percent of AOI 84.5% 15.5% 100.0% 9/23/2010 Page 3 of 3
I Master Drainage Report -Valerus-Hunter Mesa Compressor -SE Project No. t0090 October 5,2010 1 APPENDIX B (EXISTING DRAINAGE CALCULATIONS) • Existing Basin Curve Number Calculations
• Existing Basin Time of Concentration Calculations • 25-Year Runoff Summary • 2-Year Runoff Summary SOPRIS ENGINEERING • llC '7ia~l~e,~C~O~lo~ra~d-O-8~1~62~3~~(~97~O~)7~O~4-703~1~1
502 Main Street ,:,ulle A.;j vdl civil consultants lX: (970)704~0313
10090-Ex-25yr24hr-report.txt BOSS International StormNET® -version 4.20.0 (Build 675) --------------------------------------------------------------ANTERO-HUNTER MESA COMPRESSOR STATION
-25YR-24HR EXISTING DRAINAGE CALCS. **************** Analysis Options **************** Flow Un; ts ................ cfs subbasin Hydrograph Method. SCS TR-55 Time of concentration ......
SCS TR-55 Link Routing Method ....... Hydrodynamic pond Exfiltrat;on ....... , .. None Starting Date ...........•. SEP-03-2010 00:00:00 Ending Date ............... SEP-04-2010 06:00:00
Report Time step ..•....... 00:05:00 ************* Element count ***********1r* Number of rain gages ... , .. 1 Number of subbasins ....... 3 Number of nodes ........... 3 Number of
links ........... 1 **************** Raingage summary **************** Gage ID Data Source Data Type Interval hours RIFLE RAIN GAGE RIFLE 25YR-24HR CUMULATIVE 0.10 **************** subbasin
Summary **************** subbasin ID EX-OFFISTE 2 EX-ONSITE BASIN 2 EX-ONSITE-BASIN 1 *******1<**** Node Summary ************ Node ID OVERLAND Out-1 Out-2 ************ Link Summary ************
Total Area acres 0.24 1. 39 0.33 Element Type JUNCTION OUTFALL OUTFALL Li nk ID From Node Invert Elevation ft TO Node 5832.00 5820.00 5820.00 Maximum Elev. ft 5852.00 5820.50 5820.00
Element Type ponded Area ft' 0.00 0.00 0.00 Length ft External Inflow slope Manningls % Roughness OVERLAND OVERLAND Out-1 CHANNEL 233.0 5.1571 0.0320 ********************* Cross section
summary ********************* L; nk shape Depth/Width No. of Cross Full Flow ID Diameter Barrels Sect; anal Hydraulic Area Radius ft ft ft' ft Design Flow capaci ty cfs ------------------------------
----------------------------------------------------------------------------page 1
10090-EX-25yr24hr-report.txt OVERLAND TRAPEZOIDAL 0.50 12.00 1 3.50 0.29 16.19 *****11********'1<* Transect Summary **************** Transect DRYCRK-DE Area: 0.0016 0.0040 0.0066 0.0095
0.0128 0.0163 0.0201 0.0242 0.0286 0.0332 0.0382 0.0435 0.0490 0.0551 0.0645 0.0780 0.0957 0.1174 0.1419 0.1667 0.1917 0.2169 0.2422 0.2678 0.2936 0.3195 0.3456 0.3720 0.3985 0.4252
0.4521 0.4792 0.5065 0.5340 0.5617 0.5895 0.6176 0.6459 0.6743 0.7030 0.7318 0.7608 0.7901 0.8195 0.8491 0.8789 0.9089 0.9391 0.9694 1.0000 Hrad: 0.0284 0.0610 0.0904 0.1176 0.1431 0.1674
0.1907 0.2l33 0.2354 0.2569 0.2780 0.2988 0.3193 0.3433 0.3538 0.3465 0.3331 0.3201 0.3194 0.3290 0.3436 0.3614 0.3810 0.4020 0.4239 0.4464 0.4693 0.4926 0.5160 0.5395 0.5631 0.5868
0.6104 0.6340 0.6575 0.6810 0.7045 0.7278 0.7511 0.7742 0.7973 0.8202 0.8431 0.8658 0.8885 0.9110 0.9334 0.9557 0.9779 1. 0000 Width: 0.0718 0.0813 0.0908 0.1003 0.1098 0.1193 0.1287
o .l382 0.1477 0.1572 0.1667 0.1761 0.1856 0.2403 0.3742 0.5080 0.6418 0.7757 0.8051 0.8114 0.8177 0.8240 0.8303 0.8366 0.8429 0.8491 0.8554 0.8617 0.8680 0.8743 0.8806 0.8869 0.8931
0.8994 0.9057 0.9120 0.9183 0.9246 0.9309 0.9371 0.9434 0.9497 0.9560 0.9623 0.9686 0.9749 0.9811 0.9874 0.9937 1. 0000 Transect Drycrk-Ex Area: 0.0032 0.0067 0.0105 0.0149 0.0200 0.0258
0.0323 0.0396 0.0475 0.0562 0.0657 0.0758 0.0867 0.0983 0.1107 0.1237 o .l375 0.1520 0.1673 0.1832 0.1999 0.2174 0.2355 0.2544 0.2740 0.2943 0.3154 0.3371 0.3596 0.3829 0.4068 0.4315
0.4569 0.4831 0.5099 0.5375 0.5658 0.5949 0.6246 0.6551 0.6863 0.7183 0.7510 0.7844 0.8185 0.8533 0.8889 0.9252 0.9622 1.0000 Hrad: 0.0448 0.0836 0.1189 0.1582 0.1911 0.2200 0.2460 0.2700
0.2926 0.3140 0.3346 0.3546 0.3740 0.3929 0.4115 0.4298 0.4479 0.4658 0.4834 0.5010 0.5183 0.5356 0.5528 0.5699 0.5869 0.6038 0.6207 0.6375 0.6543 0.6710 0.6877 0.7043 0.7209 0.7375
0.7540 0.7706 0.7871 0.8035 0.8200 0.8364 0.8528 0.8692 0.8856 0.9020 0.9184 0.9347 0.9511 0.9674 0.9837 1.0000 Width: 0.0883 0.0961 0.1046 0.1236 0.1427 0.1617 0.1808 0.1998 0.2189
0.2379 0.2570 0.2760 0.2951 0.3141 0.3332 0.3522 0.37l3 0.3903 0.4094 0.4284 0.4475 0.4666 0.4856 0.5047 0.5237 0.5428 0.5618 0.5809 0.5999 0.6190 0.6380 0.6571 0.6761 0.6952 0.7142
0.7333 0.7523 0.7714 0.7904 0.8095 0.8285 0.8476 0.8666 0.8857 0.9047 0.9238 0.9428 0.9619 0.9809 1.0000 Transect smallcrk-Ex Area: page 2
0.0028 0.0056 10090-Ex-25lir24hr-report.txt 0.0086 0.01 6 0.0147 0.0179 0.0212 0.0246 0.0352 0.0389 0.0429 0.0648 0.0756 0.0881 0.l361 0.1556 0.1768 0.2503 0.2765 0.3032 0.3858 0.4142
0.4430 0.5322 0.5628 0.5938 0.6895 0.7222 0.7554 0.8576 0.8926 0.9279 Hrad: 0.0445 0.0866 0.1267 0.2368 0.2706 0.3033 0.3954 0.4244 0.4558 0.4726 0.4649 0.4572 0.4443 0.4442 0.4460 0.4710
0.4894 0.5092 0.5733 0.5956 0.6181 0.6863 0.7091 0.7319 0.8000 0.8226 0.8451 0.9120 0.9342 0.9562 width: 0.0770 0.0794 0.0818 0.0890 0.09l3 0.0937 0.1009 0.1033 0.1284 0.2716 0.3194
0.3672 0.5104 0.5582 0.6060 0.7134 0.7254 0.7373 0.7731 0.7851 0.7970 0.8328 0.8448 0.8567 0.8925 0.9045 0.9164 0.9522 0.9642 0.9761 ************************** volume Runoff Quantity
Continuity acre-ft ************************** ---------Total precipitation ,., ... 0.364 surface Runoff ........... 0.000 continuity Error (%) ..... -0.000 **************************
volume Flow Routing Continuity acre-ft ************************** ---------External Inflow .......... 0.000 External outflow ......... 0.039 Initial stored volume ... , 0.000 Final Stored
volume " .. " 0.000 continuity Error (%) ..... 0.000 ****************************************** composite Curve Number computations Report ******************************************
subbasin EX-OFFISTE 2 soil/surface Description sagebrush range, poor composite Area & weighted CN subbasin EX-ONSITE BASIN 2 soil/surface Description sagebrush range, poor composite
Area & weighted CN Subbasin EX-ONSITE-BASIN 1 soil/surface Description 0.0280 0.0485 0.1024 0.1998 0.3303 0.4723 0.6253 0.7891 0.9638 0.1650 0.3349 0.4740 0.4508 0.4495 0.5300 0.6407
0.7546 0.8675 0.9782 0.0842 0.0961 0.1761 0.4149 0.6537 0.7493 0.8090 0.8687 0.9284 0.9881 DeRth inc es -------2.229 0.001 volume Mgallons ---------0.000 0.0l3 0.000 0.000 0.0316 0.0558
0.1184 0.2245 0.3578 0.5020 0.6571 0.8231 1.0000 0.2016 0.3656 0.4772 0.4465 0.4545 0.5514 0.6635 0.7774 0.8898 1.0000 0.0866 0.0985 0.2239 0.4627 0.7015 0.7612 0.8209 0.8806 0.9403
1.0000 Area (acres) 0.24 0.24 Area (acres) 1. 39 1.39 Area (acres) page 3 soil Group B soil Group B soil Group eN 67.00 67.00 eN 67.00 67.00 eN
10090-Ex-2Syr24hr-report.txt ----------------------------------------------------------------------------------------Sagebrush range, Poor 0.33 B 67.00 composite Area & weighted CN 0.33
67.00 *************************************************** SCS TR-55 Time of concentration computations Report *************************************************** Sheet Flow Equation
TC = (0.007 * ((n • If)AO.8)) I ((PAO.S) • (sfAO.4)) where: Tc = Time of concentration Chrs) n = Manning's Roughness lf = Flow length (ft) p = 2 yr, 24 hr Rainfall (inches) sf = slope
(ft/ft) shallow concentrated Flow Equation v 16.134S • (sfAO.S) (unpaved surface) v 20.3282' (sfAO.S) (paved surface) v 1S.0 • (sfAO.S) (grassed waterway surface) v 10.0 • (SfAO.S) (nearly
bare & untilled surface) v 9.0 • (sfAO.S) (cultivated straight rows surface) v 7.0 • (SfAO.S) (short grass pasture surface) V S.D' (sfAO.S) (woodland surface) V 2.S· (sfAO.S) (forest
w/heavy litter surface) Tc (If I v) I (3600 sec/hr) where: Tc = Time of concentration (hrs) lf = Flow length (ft) v = velocity (ft/sec) sf = slope (ft/ft) channel Flow Equation v = (1.49
• (RA(2/3)) • (sfAO.S)) I n R = Aq I wp TC = (If I v) I (3600 sec/hr) where: TC = Time of concentration Chrs) lf = Flow length (ft) R = Hydraulic Radius (ft) Aq = Flow Area (ft') wp
= wetted perimeter (ft) v = velocity (ft/sec) sf = slope (ft/ft) n = Manning's Roughness Subbasin EX-OFFISTE 2 sheet Flow computations Manning's Rou¥hness: Flow len~th ( t): slope (%
: 2 ~r, 24 hr Rainfall (in): Ve ocity (ft/sec): computed Flow Time (minutes): shallow concentrated Flow Computations --------------------------------------Flow len~th (ft): slope (%
: subarea A 0.13 SO.OO 6.00 1.20 0.16 S .28 subarea A 100.00 2.70 page 4 Subarea B subarea c 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 subarea B subarea c 0.00 0.00
0.00 0.00
Surface Type: velocity (ft/sec): Computed Flow Time (minutes): 10090-Ex-25yr24hr-report.txt unpaved 2.65 0.63 unpaved 0.00 0.00 unpaved 0.00 0.00 =====================================================
=========================================== Total TOC (minutes): 5.91 ================================================================================================ Subbasin EX-ONSITE
BASIN 2 Sheet Flow computations Manning's Roughness: Flow Length (ft): slope (%): 2 yr. 24 hr Rainfall (in): velocity (ft/sec): Computed Flow Time (minutes): subarea A 0.13 260.00 5.40
1.20 0.21 20.60 subarea B 0.00 0.00 0.00 0.00 0.00 0.00 subarea C 0.00 0.00 0.00 0.00 0.00 0.00 ================================================================================================
Total Toe (minutes): 20.60 ============================================================================================== subbasin EX-ONSITE-BASIN 1 sheet Flow computations Manning's
Roughness: Flow Length (ft): Slope (%): 2 yr. 24 hr Rainfall (in): velocity (ft/sec): Computed Flow Time (minutes): Subarea A 0.13 255.00 5.60 1.20 0.21 19.99 subarea B 0.00 0.00 0.00
0.00 0.00 0.00 subarea C 0.00 0.00 0.00 0.00 0.00 0.00 ================================================================================================ Total Toe (minutes): 19.99 ====================
============================================================================ *********************** subbasi n Run'off Summary *********************** subbasi n 10 EX-OFFISTE 2 EX-ONSITE
BASIN 2 EX-ONSITE-BASIN 1 system ****************** Node Depth summary ****************** Total Precip in 2.200 2.200 2.200 2.200 Total Runoff in 0.240 0.240 0.240 0.240 Peak weighted
Runoff Curve cfs Number 0.050 0.210 0.050 0.28 67.000 67.000 67.000 Node 10 Average Depth Attained ft Maximum Depth Attained ft Maximum HGL Attained ft Time of Max Occurrence days hh:mm
OVERLAND Out-1 Out-2 ***************** Node Flow summary ***************** 0.00 0.00 0.00 0.03 0.02 0.00 5832.03 5820.02 5820.00 o 12:10 o 12:10 o 00:00 page 5 Time of concentrati on
days hh:mm:ss o 00:10:00 o 00:20:36 o 00:19:59 Total Flooded volume acre-in Total Time Flooded m; nutes o o o o o o Retention Time hh:mm:ss o 00 00 o 00 00 o 00 00
10090-EX-25yr24hr-report.txt ------------------------------------------------------------------------------------Node ID El ement Type Maximum Lateral Inflow cfs peak Time of Inflow
peak Inflow Occurrence cfs days hh:mm Maximum Time of peak Flooding Flooding overflow Occurrence cfs days hh:mm ------------------------------------------------------------------------------------OVE
RLAND Out-1 Out-2 JUNCTION OUTFALL OUTFALL *********************** Outfall Loading summary *********************** Outfall Node ID Out-1 Out-2 System ***************** Link Flow summary
***************** --------Flow Frequency (%) 42.07 41.29 41.68 0.05 0.21 0.05 Average Flow cfs 0.03 0.01 0.04 0.05 0.24 0.05 peak Inflow cfs 0.24 0.05 0.29 Link 1D El ement Time of Maximum
Total Type peak Flow velocity Time Occurrence Attained surcharged Minutes OVERLAND o CHANNEL ******************************** Highest Flow Instability Indexes ********************************
All links are stable. days hh:mm o 12:10 Analysis begun on: Analysis ended on: Total elapsed time: Mon Oct 04 14:09:45 2010 Mon Oct 04 14:09:47 2010 00:00:02 ft/sec 0.84 o 12 10 o 12
14 o 12 15 Length Factor 1.00 page 6 0.00 0.00 0.00 Peak Flow during Analysis cfs 0.05 Design Flow capacity cfs 16.19 Ratio of Ratio of Maximum Maximum jD€sign Flow Flow Depth 0.00 0.05
10090-EX-02yr24hr-report.txt BOSS International StormNET~ -version 4.20.0 (Build 675) ANTERO-HUNTER MESA COMPRESSOR STATION -02YR-24HR EXISTING DRAINAGE CALCS. **************** Analysis
options **************** Flow Units ................ cfs subbasin Hydrograph Method. SCS TR-55 Time of concentration ...... SCS TR-55 Link Routing Method ....... Hydrodynamic Pond Exfiltration
......... , None starting Date .....•....... SEP-03-2010 00:00:00 Ending Date ............... SEP-04-2010 06:00:00 Report Time Step .......... 00:05:00 ************* Element count *************
Number of rain gages .. , ... 1 Number of subbasins ....... 3 Number of nodes ........... 3 Number of links ......... ,. 1 **************** Raingage Summary **************** Gage ID
Data source Data Type Interval hours RIFLE RAIN GAGE RIFLE 2YR-24HR CUMULATIVE 0.10 *********************** subbasin Runoff summary *********************** subbasin ID Total prec; p
in Total Runoff in peak Runoff cfs weighted Curve Number EX-OFFISTE 2 EX-ONSITE BASIN 2 EX-ONSITE-BASIN 1 1.200 1.200 1. 200 0.000 0.008 0.000 0.000 0.002 0.000 67.000 67.000 67.000
system 1.200 0.006 0.00 ****************** Node Depth Summary ****************** Node ID Average Depth Attained ft OVERLAND out-l Out-2 ***************** Node Flow Summary *****************
0.00 0.00 0.00 Maximum Depth Attained ft 0.00 0.00 0.00 Maximum HGL Attained ft 5832.00 5820.00 5820.00 Time of Max Occurrence days hh:mm o 00:00 o 00:00 o 00:00 Time of concentration
days hh:mm:ss o 00:10:00 o 00:20:36 o 00:19:59 Total Flooded volume acre-i n Total Time Flooded minutes o o o o o o Retention Time hh:mm:ss 0:00 00 0:00 00 0:00 00 Node 10 Element Type
Maximum Lateral Inflow cfs peak Inflow Time of peak Inflow Occurrence days hh:mm Maximum Time of peak Flooding Flooding overflow Occurrence cfs OVERLAND JUNCTION 0.00 0.00 o 00:00 page
1 cfs days hh:mm 0.00
10090-EX-02yr24hr-report.txt Out-1 Out-2 OUTFALL OUTFALL 0.00 0.00 0 23:30 0.00 0.00 0.00 0 00:00 0.00 *********************** outfall Loading summary *********************** outfall
Node ID Out-l Out-2 system ***************** Link Flow summary ***************** --------Flow Frequency (%) 27.69 0.00 13.85 Average Flow cfs 0.00 0.00 0.00 peak Inflow cfs 0.00 0.00
0.00 Li nk 1D Element Time of Max; mum Total Time Surcharged Mi nutes OVERLAND o Type CHANNEL ******************************** Highest Flow Instability Indexes ********************************
All links are stable. peak Flow velocity Occurrence Attained days hh:mm ft/sec o 00:00 0.00 Analysis begun on: Mon Oct 04 Analysis ended on: Mon Oct 04 Total elapsed time: 00:00:03 14:
10: 16 2010 14:10:19 2010 Length Factor 1.00 page 2 Peak Flow duri n9 Analysis cfs 0.00 Des; gn Ratio of Ratio of Flow Maximum Maximum capacity IDesign Flow cfs Flow Depth 16.19 0.00
0.00
I Master Drainage Report -Valerus-Hunte, ,,,esa Compressor -SE Project No. 10090 October 5,2010 I APPENDIX C (POST DEVELOPMENT DRAINAGE CALCULATIONS) • Developed Basin Curve Number Calculations
• Developed Basin Time of Concentration Calculations • Developed Detention 25-Year Runoff Summary • Developed 25-Year Runoff Summary • Developed 2-Year Runoff Summary SOPRIS ENGINEERING
• llC civil consultants 502 Main street Suite A3 Carbondale, Colorado 81623 (970)704-0311 Fax: (970)704-0313
10090-DET-25yr24hr-report.txt BOSS International StormNET~ -version 4.20.0 (Build 675) ANTERQ-HUNTER MESA COMPRESSOR STATION -25YR-24HR DEVELOPED DETENTION DRAINAGE CALCS. ****************
Analysis Options **************** Flow Un; ts ................ cfs subbasin Hydrograph Method. SCS TR-55 Time of concentration ...... SCS TR-55 Link Routing Method ....... Hydrodynamic
pond Exfiltration .......... None Starting Date •............ SEP-03-2010 00:00:00 Ending Date ............... SEP-04-2010 06:00:00 Report Time Step .......•.. 00:05:00 *************
El ement count ************* Number of rain gages ...... 1 Number of subbasins ....... 3 Number of nodes ........... 5 Number of links ........... 4 "'***"'****"''''*''''''** Raingage
Summary **************** Gage ID Data Source Data T~/pe Interval hours RIFLE RAIN GAGE RIFLE 25YR-24HR CUMULATIVE 0.10 **************** Subbasi n Summary **************** subbasi n IO
Total Area acres EX-OFFISTE 2 POST-ONSITE BASIN 2 POST-ONSITE-BASIN 1 0.24 ************ Node summary ************ Node ID J-1 OVERLAND Out-1 Out-2 pond-l ************ Link Summary ************
Link ID OVERLAND POND OUT SITE OUT Reg-1 El ement Type JUNCTION JUNCTION OUTFALL OUTFALL STORAGE From Node OVERLAND pond-1 J-1 pond-1 ********************* Cross section summary *********************
1. 39 0.33 Invert Elevation ft To Node pond-1 J-1 Out-l J-1 5820.00 5832.00 5819.00 5820.00 5820.00 Maxi mum El ev. ft 5840.00 5852.00 5820.00 5820.00 5823.00 Element Type CHANNEL CHANNEL
CHANNEL ORIFICE page 1 Ponded Area ft' 0.00 0.00 0.00 0.00 0.00 Length ft 233.0 6.8 7.2 External Inflow slope Manning's % Roughness 5.1571 49.1605 14.0248 0.0320 0.0320 0.0320
Link shape 10090-DET-25yr24hr-report.txt Depth! Width No. of ID Diameter Barrels Sect;C ornoasls HFuyldlr aFuloliwc DeFs;l ogwn Area Radius capac; ty ft ft ft' ft cfs --------------------------------
--------------------------------------------------------------------------OVERLAND TRAPEZOIDAL 0.50 12.00 1 3. SO 0.29 16.19 POND OUT TRAPEZOIDAL 1.00 22.00 1 12.00 0.54 260.05 SITE
OUT TRAPEZOIDAL 1.00 22.00 1 12.00 0.54 138.90 **************** Transect summary **************** TranSect DRYCRK-DE Area: 0.0016 0.0040 0.0066 0.0095 0.0128 0.0163 0.0201 0.0242 0.0286
0.0332 0.0382 0.0435 0.0490 0.0551 0.0645 0.0780 0.0957 0.1174 0.1419 0.1667 0.1917 0.2169 0.2422 0.2678 0.2936 0.3195 0.3456 0.3720 0.3985 0.4252 0.4521 0.4792 0.5065 0.5340 0.5617
0.5895 0.6176 0.6459 0.6743 0.7030 0.7318 0.7608 0.7901 0.8195 0.8491 0.8789 0.9089 Hrad: 0.9391 0.9694 1. 0000 0.0284 0.0610 0.0904 0.1176 0.1431 0.1674 0.1907 0.2133 0.2354 0.2569
0.2780 0.2988 0.3193 0.3433 0.3538 0.3465 0.3331 0.3201 0.3194 0.3290 0.3436 0.3614 0.3810 0.4020 0.4239 0.4464 0.4693 0.4926 0.5160 0.5395 0.5631 0.5868 0.6104 0.6340 0.6575 0.6810
0.7045 0.7278 0.7511 0.7742 0.7973 0.8202 0.8431 0.8658 0.8885 0.9110 0.9334 width: 0.9557 0.9779 1. 0000 0.0718 0.0813 0.0908 0.1003 0.1098 0.1193 0.1287 0.1382 0.1477 0.1572 0.1667
0.1761 0.1856 0.2403 0.3742 0.5080 0.6418 0.7757 0.8051 0.8114 0.8177 0.8240 0.8303 0.8366 0.8429 0.8491 0.8554 0.8617 0.8680 0.8743 0.8806 0.8869 0.8931 0.8994 0.9057 0.9120 0.9183
0.9246 0.9309 0.9371 0.9434 0.9497 0.9560 0.9623 0.9686 0.9749 0.9811 0.9874 0.9937 1. 0000 Transect Drycrk-Ex Area: 0.0032 0.0067 0.0105 0.0149 0.0200 0.0258 0.0323 0.0396 0.0475 0.0562
0.0657 0.0758 0.0867 0.0983 0.1107 0.1237 0.1375 0.1520 0.1673 0.1832 0.1999 0.2174 0.2355 0.2544 0.2740 0.2943 0.3154 0.3371 0.3596 0.3829 0.4068 0.4315 0.4569 0.4831 0.5099 0.5375
0.5658 0.5949 0.6246 0.6551 0.6863 0.7183 0.7510 0.7844 0.8185 0.8533 0.8889 Hrad: 0.9252 0.9622 1.0000 0.0448 0.0836 0.1189 0.1582 0.1911 0.2200 0.2460 0.2700 0.2926 0.3140 0.3346 0.3546
0.3740 0.3929 0.4115 0.4298 0.4479 0.4658 0.4834 0.5010 0.5183 0.5356 0.5528 0.5699 0.5869 0.6038 0.6207 0.6375 0.6543 0.6710 0.6877 0.7043 0.7209 0.7375 0.7540 0.7706 0.7871 0.8035
0.8200 0.8364 0.8528 0.8692 0.8856 0.9020 0.9184 0.9347 0.9511 Width: 0.9674 0.9837 1.0000 0.0883 0.0961 0.1046 0.1236 0.1427 0.1617 0.1808 0.1998 0.2189 0.2379 0.2570 0.2760 0.2951
0.3141 0.3332 0.3522 0.3713 0.3903 0.4094 0.4284 0.4475 0.4666 0.4856 0.5047 0.5237 0.5428 0.5618 0.5809 0.5999 0.6190 page 2
0.6380 0.6571 10090-DET-25yr24hr-report.txt 0.6761 0.6952 0.7142 0.7333 0.7523. 0.7714 0.8285 0.8476 0.8666 0.9238 0.9428 0.9619 Transect Smallcrk-EX Area: 0.0028 0.0056 0.0086 0.0179
0.0212 0.0246 0.0352 0.0389 0.0429 0.0648 0.0756 0.0881 0.1361 0.1556 0.1768 0.2503 0.2765 0.3032 0.3858 0.4142 0.4430 0.5322 0.5628 0.5938 0.6895 0.7222 0.7554 0.8576 0.8926 0.9279
Hrad: 0.0445 0.0866 0.1267 0.2368 0.2706 0.3033 0.3954 0.4244 0.4558 0.4726 0.4649 0.4572 0.4443 0.4442 0.4460 0.4710 0.4894 0.5092 0.5733 0.5956 0.6181 0.6863 0.7091 0.7319 0.8000 0.8226
0.8451 0.9120 Width: 0.9342 0.9562 0.0770 0.0794 0.0818 0.0890 0.0913 0.0937 0.1009 0.1033 0.1284 0.2716 0.3194 0.3672 0.5104 0.5582 0.6060 0.7134 0.7254 0.7373 0.7731 0.7851 0.7970
0.8328 0.8448 0.8567 0.8925 0.9045 0.9164 0.9522 0.9642 0.9761 .************************* vol ume Runoff Quantity Continuity acre-ft .************************* ---------Total preCipitation
...... 0.364 surface Runoff ........... 0.000 Conti nui ty Error (%) ..•.. -0.000 ************************** volume Flow Routing continuity acre-ft ************************** ---------External
Inflow .......... 0.000 External Outflow ......... 0.090 Initial Stored volume .... 0.000 Final stored volume ...... 0.030 Continuity Error (%) ..... 0.087 ******************************************
composite Curve Number computations Report ****************************************** subbasin EX-OFF!STE 2 soil/surface Description sagebrush range, Poor composite Area & weighted CN
subbasin POST-ONSITE BASIN 2 soil/surface Description sagebrush range, Poor 0.7904 0.8857 0.9809 0.0116 0.0280 0.0485 0.1024 0.1998 0.3303 0.4723 0.6253 0.7891 0.9638 0.1650 0.3349 0.4740
0.4508 0.4495 0.5300 0.6407 0.7546 0.8675 0.9782 0.0842 0.0961 0.1761 0.4149 0.6537 0.7493 0.8090 0.8687 0.9284 0.9881 De~th inc es -------2.229 0.003 volume Mgallons ---------0.000
0.029 0.000 0.010 0.8095 0.9047 1. 0000 0.0147 0.0316 0.0558 0.1184 0.2245 0.3578 0.5020 0.6571 0.8231 1.0000 0.2016 0.3656 0.4772 0.4465 0.4545 0.5514 0.6635 0.7774 0.8898 1.0000 0.0866
0.0985 0.2239 0.4627 0.7015 0.7612 0.8209 0.8806 0.9403 1. 0000 Area (acres) 0.24 0.24 Area (acres) 0.19 page 3 soil Group B soil Group B eN 67.00 67.00 eN 67.00
Gravel roads 10090-DET-25yr24hr-report.txt 0.93 paved parking & roofs composite Area & weighted CN subbasin POST-ONSITE-BASIN 1 0.27 1. 39 Soil/surface Description Area (acres) sagebrush
range, poor Gravel roads paved parki ng & roofs composite Area & weighted CN *************************************************** scs TR-55 Time of concentration computations Report ******************
********************************* sheet Flow Equation 0.10 0.21 0.02 0.33 TC = (0.007 • ((n • If)AO.8)) /((PAO.5) • (sfAO.4)) where: Tc = Time of concentration (hrs) n = Manning's Roughness
If = Flow length (ft) P = 2 yr, 24 hr Rainfall (inches) sf = slope (ft/ft) Shallow concentrated Flow Equation v V V V V V V V 16.1345 • (sfAO.5) (unpaved surface) 20.3282 • (sfAO.5)
(paved surface) 15.0' (SfAO.5) (grassed waterway surface) 10.0 • (SfAO.5) (nearly bare & untilled surface) 9.0 * (sfAO.5) (cultivated straight rows surface) 7.0' (sfAO.5) (short grass
pasture surface) Tc = 5.0 • (sfAO.5) (woodland surface) 2.5 • (sfAO.5) (forest w/heavy litter surface) (If /v) /(3600 sec/hr) where: Tc = Time of concentration (hrs) If = Flow length
(ft) V = velocity (ft/sec) sf = slope (ft/ft) Channel Flow Equation V = (1.49' (RA(2/3)) • (SfAO.5)) /n R=Aq/Wp , Tc = (If /v) /(3600 sec/hr) where: Tc = Time of concentration (hrs)
If = Flow length (ft) R = Hydraulic Radius (ft) Aq = Flow Area (ft') wp = wetted Perimeter (ft) V = velocity (ft/sec) sf = slope (ft/ft) n = Manning's Roughness subbasin EX-OFFISTE 2
Sheet Flow computations Manning's Roughness: Subarea A 0.13 page 4 B B soil Group B B B Subarea B 0.00 85.00 98.00 85.05 CN 67.00 85.00 98.00 80.33 subarea c 0.00
Flow Length (ft): slope (%): 2 yr, 24 hr Rainfall (in): velocity (ft/sec): computed Flow Time (minutes): shallow concentrated Flow computations Flow Length (ft): slope (%): surface Type:
velocity (ft/sec): computed Flow Time (minutes): 10090-DET-25yr24hr-report.txt 50.00 6.00 1.20 0.16 5.28 subarea A 100.00 2.70 unpaved 2.65 0.63 0.00 0.00 0.00 0.00 0.00 subarea B 0.00
0.00 unpaved 0.00 0.00 0.00 0.00 0.00 0.00 0.00 subarea c 0.00 0.00 unpaved 0.00 0.00 ================================================================================================
Total Toe (minutes): 5.91 ================================================================================================ subbasin POST-ONSITE BASIN 2 sheet Flow computations Manning's
Roughness: Flow Length (ft): slope (%): 2 yr, 24 hr Rainfall (in): velocity (ft/sec): computed Flow Time (minutes): subarea A 0.13 260.00 5.40 1.20 0.21 20.60 subarea B 0.00 0.00 0.00
0.00 0.00 0.00 Subarea C 0.00 0.00 0.00 0.00 0.00 0.00 ================================================================================================ Total TOe (minutes): 20.60 ====================
============================================================================ subbasin POST-QNSITE-BASIN 1 Sheet Flow computations Manning's Roughness: Flow Length (ft): Slope (%): .
2 yr, 24 hr Rainfall (in): velocity (ft/sec): computed Flow Time (minutes): subarea A 0.13 255.00 5.60 1.20 0.21 19.99 Subarea B 0.00 0.00 0.00 0.00 0.00 0.00 subarea c 0.00 0.00 0.00
0.00 0.00 0.00 ================================================================================================ Total Toe (minutes): 19.99 ============================================================
==================================== *********************** subbasin Runoff Summary *********************** subbasin ID EX-OFFISTE 2 POST-ONSITE BASIN 2 POST-ONSITE-BASIN 1 System ******************
Node Depth Summary ****************** Total precip in 2.200 2.200 2.200 2.200 Total Runoff in 0.240 0.947 0.703 0.820 peak weighted Runoff Curve cfs Number 0.050 1.410 0.250 1.69 67.000
85.050 80.330 Node ID Average Depth Attained Maximum Depth Attained Maximum HGL Attained Time of Max Occurrence Page 5 Time of Concentration days hh:mm:ss o 00:10 00 o 00 20:36 o 00
19:59 Total Flooded volume Total Time Flooded Retention Time
ft ft 10090-DET-25yr24hr-report.txt ft days hh:mm acre-in minutes hh:mm:ss -----------------------------------------------------------------------------------------J-1 OVERLAND Out-l
Dut-2 pond-1 ***************** Node Flow Summary ***************** Node ID J-1 OVERLAND Out-1 Out-2 pond-1 0.01 0.00 0.01 0.00 0.79 Element Type JUNCTION JUNCTION OUTFALL OUTFALL STORAGE
********************** Detention Pond summary ********************** ---------------------0.02 0.02 0.02 0.00 1. 54 5820.02 5832.02 5819.02 5820.00 5821. 54 o 15: 13 o 12:11 o 15: 13
o 00:00 o 15: 13 Maximum peak Time of Lateral Inflow cfs Inflow Peak Inflow Occurrence cfs days hh:mm 0.00 0.05 0.00 0.24 1.40 0.07 0.05 0.07 0.24 1.44 o 15:13 o 12:10 o 15:l3 o 12:10
o 12:10 o o o o o o o o o o 0:00 00 0:00 00 0:00 00 0:00 00 0:00 00 Maximum Time of peak Fl oodi ng Fl oodi ng overflow Occurrence cfs days hh:mm 0.00 0.00 0.00 0.00 0.00 Detention pond
10 Maximum Maximum Time of Max Average Average Maxi mum Time of Max. Total Maximum ponded Ponded ponded ponded ponded pond Exfiltration Exfiltrat;on EXfi 1 trated volume Rate volume
1000 ft' hh:mm:ss 1000 ft' pond-1 1.486 0:00:00 0.000 *********************** Outfall loading summary *********************** outfall Node ID Out-1 Out-2 system ***************** Link
Flow summary ***************** Flow Frequency (%) 58.94 43.61 51.27 volume volume Average Flow cfs 0.05 0.02 0.07 (%) days hh:mm 39 peak Inflow cfs 0.07 0.24 0.24 o 15: l3 volume volume
Outflow Rate 1000 ft' (%) cfs cfm 0.733 19 0.07 0.00 --------------------------------------------------------------------------------------------------------------------link ID El ement
Ti me of Maximum Length peak Flow Desi gn Rati 0 of Ratio of Total Type peak Flow velocity Factor duri ng Flow Maximum Maximum Time occurrence Attained Anal ysi s capacity jDesi gn Flow
surcharged days hh:mm ftjsec cfs cfs Flow Depth Minutes page 6
10090-DET-25yr24hr-report.txt --------OVERLAND CHANNEL 0 POND OUT CHANNEL 0 SITE OUT CHANNEL 0 Reg-1 ORIFICE ******************************** Highest Flow Instability Indexes ************************
******** All links are stable. 0 12:11 0 00:00 0 15:13 0 15:13 Analysis begun on: Analysis ended on: Total elapsed time: Mon Oct 04 14:08:48 2010 Mon Oct 04 14:08:51 2010 00:00:03 0.03
1.00 0.00 1.00 l.34 1.00 page 7 0.04 16.19 0.00 0.52 0.00 260.05 0.00 0.01 0.07 138.90 0.00 0.02 0.07 1. 00
10090-DE-25yr24hr-report.txt BOSS International storrnNET® -version 4.20.0 (Build 675) ANTERO-HUNTER MESA COMPRESSOR STATION -25YR-24HR DEVELOPED DRAINAGE CALCS. ~*************** Analysis
options ****************. Flow Un; ts ................ cfs subbasin HydrDgraph Method. SCS TR-55 Time of concentration ...... SCS TR-S5 Link Routing Method ....... Hydrodynamic Pond
Exfiltration .......... None starting Date ••..........• SEP-03-2010 00:00:00 Ending Date .•............• SEP-04-2010 06:00:00 Report Time step .......... 00:05:00 ************* Element
count ************* Number of rain gages ..... , 1 Number of subbasins ....... 3 Number of nodes ........... 3 Number of links ........... 1 **************** Rainaage summary ****************
Gage ID Data Source Data Type Interval hours RIFLE RAIN GAGE RIFLE 25YR-24HR CUMULATIVE 0.10 *********************** subbasin Runoff summary *********************** subbasi n ID EX-OFFISTE
2 POST-ONSITE BASIN 2 POST-ONSITE-BASIN 1 system ****************** Node Depth summary ****************** Total precip in 2.200 2.200 2.200 2.200 Total Runoff in 0.240 0.947 0.703 0.820
peak weighted Runoff Curve cfs Number 0.050 1.410 0.250 1.69 67.000 85.050 80.330 Node ID Average Depth Attained ft Maximum Depth Attained ft Maximum HGL Attained ft Time of Max Occurrence
days hh: mm OVERLAND out-1 out-2 ***************** Node Flow summary ***************** 0.00 0.00 0.00 0.03 0.02 0.00 5832.03 5820.02 5820.00 o 12:10 o 12:10 o 00:00 Time of Concentration
days hh:mm:ss o 00:10:00 o 00:20:36 o 00:19:59 Total Flooded volume acre-i n o o o Total Time Flooded minutes o o o Retention Time hh:mm:ss 0:00 00 0:00 00 0:00 00 Node ID Element Type
Maximum Lateral Inflow cfs Peak Time of Maximum Time of peak Inflow Peak Inflow Flooding Flooding Occurrence overflow Occurrence cfs days hh:mm cfs days hh:mm page 1
OVERLAND Out-1 Out-2 10090-DE-25yr24hr-report.txt JUNCTION 0.05 0.05 0 12:10 0.00 OUTFALL OUTFALL 1.40 1.45 0 12:10 0.00 0.24 0.24 0 12:10 0.00 *********************** Outfall Loading
summary *********************** outfall Node ID Out-1 Out-2 system ***************** Link Flow Summary ***************** --------Flow Frequency (%) 49.18 43.61 46.39 Average Flow cfs
0.09 0.02 0.11 peak Inflow cfs 1.45 0.24 1.69 Link 1D Element Time of Maximum Total Type Peak Flow velocity Time Occurrence Attained surcharged Minutes OVERLAND o CHANNEL ****************************
**** Highest Flow Instability Indexes ******************************** All links are stable. days hh:mm o 12:10 Analysis begun on: Man Oct 04 14:06:05 2010 Analysis ended on: Man Oct
04 14:06:08 2010 Total elapsed time: 00:00:03 ft/sec 0.84 Length Factor 1.00 page 2 Peak Flow duri n9 Analysis cfs 0.05 Design Ratio of Ratio of Flow Maximum Maximum capacity /Design
Flow cfs Flow Depth 16.19 0.00 0.05
10090-DE-02yr24hr-report.txt BOSS International StormNET® -version '4.20.0 (Build 675) --------------------------------------------------------------ANTERO-HUNTER MESA COMPRESSOR STATION
-02YR-24HR DEYELOPED DRAINAGE CALCS. *****"'****"'***** Analysis options **************** Flow un; ts ................ cfs subbasin Hydrograph Method. SCS TR-55 Time of concentration
...... SCS TR-SS Link Routing Method ....... Hydrodynamic pond Exfiltration .......... None starting Date ..•...•...•.. SEP-03-2010 00:00:00 Ending Date ............... SEP-04-2010 06:00:00
Report Time Step .....•.... 00:05:00 ************* ~1 ernent Count ************* Number of rain gages ... ". 1 Number of subbasins 0.'. ", 3 Number of nodes ........... 3 Number of links
........ ". 1 ***"''''*********** Raingage summary **************** Gage ID Data Source Data Type Interva 1 hours RIFLE RAIN GAGE RIFLE 2YR-24HR CUMULATIVE 0.10 ***********************
subbasin Runoff summary *********************** subbasin 1D EX-OFFISTE 2 POST-ON SITE BASIN 2 POST-ONSITE-BASIN 1 system ****************** Node Depth summary ****************** Total
Precip in 1.200 1.200 1.200 1.200 Total Runoff in 0.000 0.276 0.159 0.223 peak weighted Runoff Curve cfs Number 0.000 0.360 0.040 0.39 67.000 85.050 80.330 Node 10 Average Depth Attai
ned ft Maximum Maximum Time of Max Occurrence OVERLAND OU1:-1 out-2 ***************** Node Flow summary ***************** 0.00 0.00 0.00 Depth HGL Attained Attained ft ft 0.00 0.00 0.00
5832.00 5820.00 5820.00 days hh:mm o 00:00 o 00:00 o 00:00 Time of concentration days hh:mm:ss o 00:10:00 o 00:20:36 o 00:19:59 Total Flooded volume acre-i n o o o Total Time Flooded
minutes o o o Retention Time hh:mm:ss 0:00 00 0:00 00 0:00 00 Node ID Element Type Maximum Lateral Inflow cfs Peak Time of Maximum Time of peak Inflow peak Inflow Flooding Flooding Occurrence
overflow Occurrence cfs days hh:mm cfs days hh:mm page 1
10090-DE-02yr24hr-report.txt OVERLAND Out-l Out-2 JUNCTION OUTFALL OUTFALL 0.00 0.00 0 00:00 0.00 0.35 0.35 0 12:14 0.00 0.04 0.04 0 12:14 0.00 *********************** Outfall Loading
Summary *********************** Outfa 11 Node ID Out-1 Out-2 system ***************** Link Flow summary ***************** --------Flow Frequency (%) 42.51 41.04 41.78 Average Flow cfs
0.03 0.00 0.03 Peak Inflow cfs 0.35 0.04 0.39 Link 1D Element Time of Maximum Total Type peak Flow velocity Time Occurrence Attained surcharged Minutes OVERLAND o CHANNEL ****************************
**** Hiohest Flow Instability Indexes ******************************** All links are stable. days hh:mm o 00:00 Analysis begun on: Mon Oct 04 14:04:58 2010 Analysis ended on: Mon Oct
04 14:05:01 2010 Total elapsed time: 00:00:03 ftlsec 0.00 Length Factor 1.00 page 2 Peak Flow duri ng Analysis cfs 0.00 Design Ratio of Ratio of Flow Maximum Maximum capacity IDesign
Flow cfs Flow Depth 16.19 0.00 0.00
II i I I I ! I ! I ! r ! I ! I "'" I " I PRE-DEVELOPMENT DRAINAGE EXHIBIT ~_.J I I ! I GRAPHIC SCALE i i i ( IN FEEl' ) 1 inch .. 40 " ~ --/__ ---------SW'C ----------~ ". I " -/;. "-,
/" \/"I ,'I ,. I , I , PARCfL j-RfC. NO. 71l99i;Tc5l511: 1919 PAGf63 mlf fliCfPTION NO. 40 ,101.481.1 sa Fr. </-,,1.330 ACRfS'/-, '---. , I~ ---.I POST DRAINAGE EXHIBIT G2l DRAINAGE
NOTES: , , , I , " I ,, I I "1;1: LF. 8" P\c SOR J5 11'/2" 0RmC£ CAP A r OU1lET I)f' ",r-\. DDEN'TICH FACIUTY (2.I(}();i at I)f' SltlfMGE") EXlSTlNG COtITOIJRS ARE AT l' FOOT INlERV.oLS
ISHADEO N-fJ DI\SHED, 2 PROPOSED COIHOORS AAE AT ,. FOOT WERVN.S 3. TIlE DHENTUJN POND 'liN> SIZCO FOR THE PR~ & POST DlNELOPED FLOWS FOR Tt£ ts-YR STORM EVENT. THE rn·~ HYORAUUC METHOO
W!\$USED FOR THIS mAl. ¥SIS SITE PL.OIIINFORMATION WAS PROVJOED ByOTl-<ERS ~ MINUTES WAS USED AS Tl-<E MINIMuM I1MI'-OF CONcENTAATlON z 0 ;>:=: 0 t:: en Cl CD z ~ :Xi: 0 0 W Uen; -0
' two w U « a:: ~-z >-0-;;;: m ::. z a:: :i: 0 ::::J Cl [IS U« 0u >en-en Cl 0 :W:. -W' 000-a:: u: w a:: w >-« a:: z to 0-::::J :I: DATE: 10-05·10 JOB NO. 10090 M:1300i)dwgs\10090ldesignIDRGl1009()..D
RAINAGE·PLOT.dwg, 101512010 4:11: ~ann 1 OF 1