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Home My WebLink About20082288.tiff Weld County Planning Department j GREELEY OFFICE JIli.. 05 7flrl� • RECEIVED GEOTECHNICAL SUBSURFACE EXPLORATION AND GEOLOGIC HAZARDS REPORT NEBARADO DEVELOPMENT WELD COUNTY, COLORADO EEC PROJECT NO. 06-01-148 • • EXHIBIT 2008-2288 a ' ,_ EEC • EARTH ENGINEERING COMPANY, INC. August 24, 2006 Revised: February 22, 2008 Nebarado Construction 6804 Aaron Drive Fort Collins, Colorado 80524 Attn: Mr. Gary Mackey Re: Geotechnical Subsurface Exploration and Geologic Hazards Report Nebarado Development Weld County, Colorado EEC Project No. 06-01-148 Mr. Mackey: • Enclosed, herewith, are the results of the subsurface exploration and geologic hazards evaluation completed by Earth Engineering Company, Inc. personnel for the referenced project. In summary, the subsurface materials encountered in the test borings consisted of non plastic sand and gravel materials underlain by fine sand and highly plastic fat clay soils. Groundwater was not observed in the completed site borings at the time of our observations. Based on the materials we observed at the boring locations, we believe lightly loaded residential structures could be supported on conventional footing foundation bearing in the near surface sand and gravel soils. The sand and gravel materials could be used for direct support of floor slabs and pavements. Percolation tests were performed at three boring locations and indicated that both conventional systems could be utilized and engineered systems would be required at the proposed development. Geotechnical recommendations conceming design and construction of foundations and support of floor slabs and pavements are presented in the text of the attached report. • P.O. Box 271428 P.O. Box 49322 FORT COLLINS, COLORADO 80527-1428 COLORADO SPRINGS, COLORADO 80949-9322 (970) 224-1522 (Fax) 663-0282 (719) 442-6813 (FAx) 447-9635 •, Earth Engineering Company,Inc. EEC Project No.06-01-148 August 24,2006 Revised: February 22,2008 • Page 2 We appreciate the opportunity to be of service to you on this project. If you have any questions concerning the enclosed report, or if we can be of further service to you in any other way,please do not hesitate to contact us. Very truly yours, Earth Engineering Company, Inc. no0 REG/Sr 0:.•�1oseFy..F,� O ' oo:cO 3572 • SI AL Michael J. Coley, P.E. Principal Engineer MJC/dla • • GEOTECHNICAL SUBSURFACE EXPLORATION AND GEOLOGIC HAZARDS REPORT NEBARADO DEVELOPMENT WELD COUNTY, COLORADO EEC PROJECT NO. 06-01-148 August 24, 2006 Revised: February 22, 2008 INTRODUCTION The geotechnical subsurface exploration and geologic hazards report for the Nebarado Development located in an area to the North of Weld County Road 84 and east of Weld County Road 37 in Weld County, Colorado, has been completed. The results of our • preliminary geotechnical subsurface exploration and geologic hazards evaluation for the proposed development are presented in this report.Nine(9)soil borings extending to depths of approximately 8 to 1512 feet below present site grades were advanced in the proposed development area to obtain information on existing subsurface conditions. Individual boring logs and a diagram indicating the approximate boring locations are included with this report. The proposed project includes approximately 30 acres to be developed as single-family residential. We expect the residential structures will be one or two-story, wood frame buildings constructed on full basements. Foundation loads for the proposed residences are expected to be light with continuous wall loads less than 2.5 kips per lineal foot and column loads less than 35 kips. Floor loads are expected to be less than 100 psi It is expected the site roadways will be used by low volumes of automobiles and light trucks. Small grade changes are expected to develop final site grades. The purpose of this report is to describe the subsurface conditions encountered in the site borings, analyze and evaluate the test data and provide geotechnical recommendations • concerning design and construction of foundations and support of floor slabs and pavements. Earth Engineering Company,Inc. • EEC Project No. 06-01-148 August 24,2006 Page 2 The results of three(3)percolation tests completed at the site are also included.In addition,a geologic hazards evaluation is provided. GEOLOGIC HAZARDS EVALUATION Earth Engineering Company, Inc. (EEC) personnel have completed the geologic hazards evaluation you requested for the referenced project. That evaluation was completed by reviewing readily available data concerning soil and groundwater conditions at the site, principally through review of United States Geologic Society (USGS)/Colorado Geologic Society (CGS) and Department of Agriculture Soil Conservation Service (SCS) published information. A listing of the references reviewed as a part of the geologic hazard study is included with this report. • The Nebrado Development Property is located in the Northwest''/a of Section 6,T7N,R65W of the 6th P.M. in Weld County,Colorado.The residential portion of the development parcel includes approximately 26 acres. Site drainage appears to be generally to the southeast. Total elevation change across the site on the order of 5 feet. A diagram indicating the approximate location of the development is included with this report. _ The attached soil classification map includes demarcation of those soil groupings identified on the site by SCS Weld County soil maps. SCS descriptions of those soil types are provided with this report. In general,the near surface soils at this site appear to be a blend of low to moderate clay loam soils with varying amounts of silt. The SCS information indicates the property would be expected to have groundwater at depths greater than 6 feet. The Soil Conservation Service maps of the area indicate the near surface soils are predominately of the Dacono soil grouping. The Dacono soil group is predominately a clay loam and is moderately plastic.Those soils appear to be wind-blown deposits(Eolium)of the Upper Holocene age consisting of clay,silt and sand.According to the geologic maps of the area,the soil groupings mapped by the SCS are underlain by the undifferentiated valley fill • deposits of the Quaternary (Pleistocene/Holocene) age. The undifferentiated valley fill Earth Engineering Company,Inc. • EEC Project No.06-01-148 August 24,2006 Page 3 deposits generally consist of sand and gravel. According to SCS data, depth to bedrock is greater than 60 inches. Based on our review of the site as outlined above,we expect the near surface soils could be used for support of lightly loaded residential structures. More heavily loaded structures may require deep foundations. The near surface soils appear to exhibit a low potential for volume change with variation in moisture content. Based on our past experience,we anticipate that the Dacono series would exhibit percolation rates to support conventional septic absorption systems;however,the underlying granular soils may require blending with finer grained soils to develop suitable percolation rates. During our review of available site data,we did not identify other potential geologic hazards as outlined in H.B. 1041. We did identify the potential for economically recoverable mineral • resources, consisting of gravel/aggregate deposits as defined in H.B. 1041 at this site. The evaluation for this report was based on a review of readily available public information for the property and prior experience in the general area. EXPLORATION AND TESTING PROCEDURES The boring locations were selected and established in the field by a representative of Nebarado Construction and by EEC personnel by estimating angles and distances from identifiable site references. The locations of the borings should be considered accurate only to the degree implied by the methods used to make the field measurements. The borings were performed using a truck mounted CME-45 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers. Samples of the subsurface materials encountered were obtained using split-barrel and California barrel sampling procedures in general accordance with ASTM Specification D-1586. In the split-barrel and California • barrel sampling procedures,standard sampling spoons are driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to Earth Engineering Company,Inc. • EEC Project No.06-01-148 August 24,2006 Page 4 advance the samplers is recorded and is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy,the consistency of cohesive soils and hardness of weathered bedrock. In the California barrel sampling procedure, relatively undisturbed samples are obtained in removable brass liners. All samples obtained in the field were sealed and returned to the laboratory for further examination,classification and testing. As part of the field-testing,percolation tests were performed in the prepared percolation test holes located at each of three(3)soil profile borings. Six(6)percolation test holes to depths of approximately 3 feet were advanced at each boring location to develop percolation and soil profile information. Percolation tests were completed after presoaking the test holes for approximately 24 hours. Results of the percolation testing are provided subsequently in this report. Groundwater measurements were taken at the time of drilling and approximately 24 hours • after the completion of drilling. Free water was not observed at the time of drilling and approximately 24 hours after drilling in the completed site borings. Moisture content tests were performed on each of the recovered samples. In addition, selected samples were tested for swell/consolidation, fine content and plasticity by washed sieve analysis and Atterberg limits tests. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As a part of the testing program,all samples were examined in the laboratory by an engineer and classified in accordance with the attached General Notes and the Unified Soil Classification System, based on the sample's texture and plasticity. The estimated group symbol for the Unified Soil Classification System is shown on the boring logs and a brief description of that classification system is included with this report. Classification of the bedrock was based on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. • Earth Engineering Company,Inc. • EEC Project No. 06-01-148 August 24,2006 Page 5 SITE AND SUBSURFACE CONDITIONS The development parcel is located in an area to the north of Weld County Road 84 and east of Weld County Road 37, northeast of Ault in Weld County, Colorado. The project site is presently undeveloped and was relatively flat. An EEC field engineer was on-site during drilling to direct the drilling activities and evaluate the subsurface materials encountered. Field descriptions of the materials encountered were based on visual and tactual observation of disturbed samples and auger cuttings. The boring logs included with this report may contain modifications to the field logs based on results of laboratory testing and engineering evaluation. Based on results of field and laboratory evaluation, subsurface conditions can be generalized as follows. • Dark brown sand and gravel materials were encountered at the surface of the boring locations. The dark brown sand and gravel materials contained a slight amount of clay and were underlain by brown sand and gravel materials at a depth of approximately 12 inches below present site grades. The non-plastic sand and gravel materials were generally medium dense to dense in consistency and were underlain by brown fine sand materials at four boring locations at a depth of approximately 9 to 13 feet below present site grades. The fine sand materials were slightly clayey to clayey and contained a slight amount of gravel. The fine sand materials were generally medium dense in consistency and exhibited a low potential for swelling with increase in moisture content at current moisture/density conditions. The fine sand materials extended to the bottom of those borings at depths of approximately 151/2 feet below present site grades. The near surface sand and gravel materials were underlain by grey/brown and olive fat clay soils at two boring locations at a depth of approximately 10 feet below present site grades.The highly plastic fat clay soils were generally medium stiff to stiff in consistency and exhibited a low potential for swelling with increase in moisture content at current moisture/density conditions. The fat clay soils encountered in two of the borings extended to the bottom of one those borings at a depth of approximately 15 feet below present site grades.The fat clay soils encountered in the other boring was underlain by brown • clayey sand materials at a depth of approximately 14 feet below present site grades. The Earth Engineering Company,Inc. • EEC Project No.06-01-148 August 24,2006 Page 6 clayey sand materials were dense in consistency, contained a slight amount of gravel and extended to the bottom of that boring at a depth of approximately 15 %1 feet below present site grades. The stratification boundaries indicated on the boring logs represent the approximate location of changes in soil types; in-situ, the transition of materials may be gradual and indistinct. GROUND WATER OBSERVATIONS Observations were made while drilling and approximately 24 hours after the completion of drilling to detect the presence and level of free water. Free water not observed in the completed site borings at the time of drilling and approximately 24 hours after drilling. Perched and/or trapped water may be encountered in more permeable zones in the subgrade • soils at times throughout the year. Perched water is commonly encountered in soils immediately overlying less permeable bedrock materials. Fluctuations in ground water levels and in the location and amount of perched water may occur over time depending on variations in hydrologic conditions,irrigation activities on surrounding properties and other conditions not apparent at the time of this report. We have typically noted lowest groundwater levels in late winter and shallowest groundwater levels in mid to late summer. Additional monitoring of groundwater levels on the site could be completed to help determine seasonally high groundwater levels. ANALYSIS AND RECOMMENDATIONS Site Preparation All existing vegetation and/or topsoil should be removed from beneath fill, roadway or building subgrade areas. After stripping and completing all cuts and prior to placement of • any fill, floor slabs or pavements, we recommend the exposed soils be scarified to a Earth Engineering Company,Inc. • EEC Project No.06-01-148 August 24,2006 Page 7 minimum depth of 9 inches, adjusted in moisture content and compacted to be at least 95% of the material's maximum dry density as determined in accordance with ASTM Specification D-698,the standard Proctor procedure. The moisture content of the scarified materials should be adjusted to be within the range of±2% of standard Proctor optimum moisture at the time of compaction. Fill soils required to develop the building area or pavement subgrades should consist of approved,low-volume change materials which are free from organic matter and debris. The near surface sand and gravel soils could be used as fill in these areas. We recommend the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as recommended for the scarified materials and compacted to be at least 95%of the material's standard Proctor maximum dry density. Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials. Positive drainage should be developed away from the structures and across and away from the pavement edges to avoid wetting of subgrade materials. Subgrade materials allowed to become wetted subsequent to construction of the residences and/or pavements can result in unacceptable performance of those improvements. The site soils would be subject to strength loss and instability at elevated moisture contents. If construction occurs during wet periods, it may be necessary to stabilize the subgrades for completion of paving and instability should be expected in the building subgrades. Footing Foundations Based on the materials observed at the test boring locations, it is our opinion the proposed lightly-loaded residence could be supported on conventional footing foundations bearing on the natural site soils. For design of footing foundations bearing on the natural medium dense to dense sand and gravel soils,we recommend a net allowable total load bearing of 1,500 psf be used. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load should include full dead and • live loads. Earth Engineering Company,Inc. • EEC Project No. 06-01-148 August 24,2006 Page 8 Exterior foundations and foundations in unheated areas should be located a minimum of 30 inches below adjacent exterior grade to provide frost protection. We recommend formed continuous footings have a minimum width of 12 inches and isolated column foundations have a minimum width of 24 inches. Trenched foundations or grade beam foundations should not be used in the sand and gravel soils. No unusual problems are anticipated to excavate for construction of the footings. Care should be taken during construction to avoid disturbing the foundation bearing materials. Materials which are loosened or disturbed by construction activities or which become dry and desiccated or wet and softened should be removed and replaced or reworked in place prior to placement of foundation concrete. Floor Slab Subgrades • We recommend all existing vegetation/topsoil be removed from beneath the floor slab areas. After stripping and completing all cuts and prior to placement of any floor slabs or fill,the exposed subgrades should be scarified, adjusted in moisture content and recompacted as outlined under "Site Development." Fill soils required to develop the floor slab subgrades should consist of approved, low- volume change materials which are free from organic matter and debris. The near surface sand and gravel soils could be used for fill beneath floor slabs. Those materials should be placed and compacted as outlined for the site fill soils. Care should be taken after development of the floor slab subgrades to prevent disturbance of the in-place materials. Materials which are loosened or disturbed by construction activities or materials which become wet and softened or dry and desiccated should be reworked prior to placement of the overlying floor slabs. • Earth Engineering Company,Inc. • EEC Project No.06-01-148 August 24,2006 Page 9 Pavement Subgrades All existing vegetation and/or topsoil should be removed from pavement areas. After stripping and completing all cuts and prior to placement of any fill or pavements, we recommend the exposed soils be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to be at least 95%of the material's maximum dry density as determined in accordance with the standard Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the range of t2%of standard Proctor optimum moisture. Fill materials required to develop the pavement subgrades should consist of approved,low- volume change materials, free from organic matter and debris. The near surface sand and gravel soils could be used for fill in these areas. We recommend those fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as • recommended for the scarified materials above. After completion of the pavement subgrades,care should be taken to prevent disturbance of those materials prior to placement of the overlying pavements. Soils which are disturbed by construction activities should be reworked in-place or, if necessary,removed and replaced prior to placement of overlying fill or pavements. The site soils would be subject to strength loss and instability at elevated moistures. If subgrades below are wetted at the time of construction, it may be necessary to stabilize the subgrades prior to placement of the pavement section. Stabilization may also be needed in areas where the groundwater levels are relatively near the surface. In addition,care will be needed during and after construction phases to prevent wetting of the pavement subgrades. Pavements We expect traffic for the proposed development will include low volumes of automobiles and light trucks. Weld County standards require a minimum pavement section of 4 inches of • hot bituminous asphalt pavement overlying 6 inches of aggregate base for"local"roadways. Earth Engineering Company,Inc. • EEC Project No. 06-01-148 August 24,2006 Page 10 Surface course asphaltic concrete for use in the pavement areas should be consistent with Weld County criteria for Grading S or SX materials. The aggregate base should be consistent with Larimer County requirements for Class 5 or Class 6 base material. Alternative pavement sections could be considered and we would be pleased to provide alternative section recommendations, at your request. Site Percolation Tests Percolation tests were completed in the identified areas of the individual wastewater absorption field located at each of three(3) soil profile borings. The materials encountered in the test borings consisted of brown sand and gravel materials which extended to the bottom of the profile borings at a depth of approximately 8 feet below present site grades.At the time of drilling and approximately 24 hours after drilling,groundwater was not observed • in the completed profile borings. Average percolation rates of 5, 5.1 and 0.7 minutes per inch were established in each of the percolation test borings at the three soil profile borings. Weld County guidelines require a percolation rate in the range of 5 to 60 minutes per inch for use of a non-engineered conventional absorption field. The measured percolation rates at one of the three percolation test areas do not meet that criterion. In addition, the Weld County guidelines require that groundwater or bedrock not be encountered within 6 feet of ground surface at the location of an absorption field. The profile borings indicate the near surface site soils do meet the groundwater and bedrock criteria in those areas at the time of our exploration. Based upon our site observations as outlined above, both conventional and engineered systems would be required for the proposed development. In siting of the absorption fields,Weld County criteria concerning proximity to drainage ways and other site features should be addressed. • Earth Engineering Company,Inc. • EEC Project No.06-01-148 August 24,2006 Page 11 GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If variations appear evident, it will be necessary to re-evaluate the recommendations of this report. It is recommended that the geotechnical engineer be retained to review the plans and specifications so that comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during • earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Nebarado Construction for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. In the event that any changes in the nature, design or location of the project as outlined in this report are planned,the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions of this report modified or verified in writing by the geotechnical engineer. • DRILLING AND EXPLORATION DRILLING&SAMPLING SYMBOLS: SS: Split Spoon- 13/8"I.D.,2" O.D.,unless otherwise noted PS: Piston Sample • ST: Thin-Walled Tube-2" O.D.,unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler-2.42" I.D.,3" O.D.unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit=4",N,B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard"N"Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.D.split spoon,except where noted. WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WS : While Sampling WCI: Wet Cave in WD : While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB : After Boring ACR: After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils,the indicated levels may reflect the location of ground water. In low permeability soils,the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION PHYSICAL PROPERTIES OF BEDROCK Soil Classification is based on the Unified Soil Classification DEGREE OF WEATHERING: system and the ASTM Designations D-2488. Coarse Grained Slight Slight decomposition of parent material on Soils have move than 50%of their dry weight retained on a#200 joints. May be color change. sieve;they are described as: boulders,cobbles,gravel or sand. Moderate Some decomposition and color change • Fine Grained Soils have less than 50% of their dry weight throughout. retained on a#200 sieve;they are described as : clays,if they High Rock highly decomposed, may be extremely are plastic, and silts if they are slightly plastic or non-plastic. broken. Major constituents may be added as modifiers and minor HARDNESS AND DEGREE OF CEMENTATION: constituents may be added according to the relative proportions Limestone and Dolomite: based on grain size. In addition to gradation, coarse grained Hard Difficult to scratch with knife. soils are defined on the basis of their relative in-place density Moderately Can be scratched easily with knife. and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff(CL); silty Hard Cannot be scratched with fingernail. sand,trace gravel,medium dense(SM). Soft Can be scratched with fingernail. CONSISTENCY OF FINE-GRAINED SOILS Shale. Siltstone and Claystone: Hard Can be scratched easily with knife,cannot be scratched with fingernail. Unconfined Compressive Strength,Qu,psf Consistency Moderately Can be scratched with fingernail. Hard < 500 Very Soft Soft Can be easily dented but not molded with 500- 1,000 Soft fingers. 1,001 - 2,000 Medium Sandstone and Conglomerate: 2,001 - 4,000 Stiff Well Capable of scratching a knife blade. 4,001 - 8,000 Very Stiff Cemented 8,001 - 16,000 Very Hard Cemented Can be scratched with knife. RELATIVE DENSITY OF COARSE-GRAINED SOILS: Poorly Can be broken apart easily with fingers. N-Blows/ft Relative Density Cemented 0-3 Very Loose • 4-9 Loose 10-29 Medium Dense EEC ',. 30-49 Dense G G 50-80 Very Dense 80+ Extremely Dense - ------ / D Son.CLASSIFICATION SYSTEM • Soil Classification Group Group Name Criteria for Assigning Group Symbols and Group names Using Laboratory Tests Symbol Coarse—Grained Grovels more than Clean Gravels Less Soils more than 50% of coarse than 5% fines Cu>4 and <Cc≤3` GW Well—graded gravel' 50% retained on fraction retained • No. 200 sieve on No. 4 sieve Cu<4 and/or 1>Cc>3` GP Poorly—graded gravel' Gravels with fines Fines classify as ML or MH GM Silty grovel, G,H more than 12% . fines Fines classify as CL or CH GC Clayey Grovel"F" Sands 50% or Clean Sands Less Cu>5 and 1<Cct3` sw Well—graded sand' more coarse than 5% fines fraction passes Cu<b and/or 1>Cc>3` SP Poorly—graded sand' No. 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand c''' more than 12% fines Fines classify as CL or CH SC Clayey sand" Fine—Grained Silts and Clays inorganic PI>7 and plots art or above 'A'Line4 CL Lean clay' Soils 50% or Liquid Limit less more posses the than 50 P1<4 or plots below 'A'Line' ML Slt"*" No. 200 sieve organic Liquid Limit — oven dried Organic clay=," <0.75 OL Liquid Limit — not dried Organic silt I''•." Silts and Clays inorganic PI plots on or above 'A"Line CH Fat clay°"' Liquid Limit 50 or more PI plots below "A"Line MH Elastic Silt"" III organic Liquid Limit — oven dried Organic clay' <0.75 OH Liquid Limit — not dried Organic silt""° Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat %oiled on the material passing the 3—in. (75— a (Ds) 'if sot contains 15 to 29%plua No. 200. odd mm) sieve Cu— vl Cam D x d 'with sand' or •e11h graver, whichever Is IN field sample contained cobbles or boulder,, predominant or both, add 'with cobbles or boulders, or both' 'If sad contains 2 30' plus No. 200 to group name. "If soil contains 215X wand, add'with•sand'lo predominantly sand, add'sandy to group °Graveie with 5 to 12X fines required duol name. symbol= group name "If sod contains 2 30%plus No. 200 GW—GIA wail graded gravel with wilt °If fines classify as CL—ML, use dual symbol predominantly gravel. odd 'gravely' to group GW—GC well—gradedgrovel with day — w'SC—SM. 4 '1f fines ore organic, add'wlth organic fine,to M�1°' GP-GM paorly-groded gravel with silt group name °P124 and plats on or above 'A' line. GP-GC poorly-graded gravel with day sod con loins >15Xgravei, add'w11h gravel' °Pis. Or plots below'A' lice. 15onds with 3 to 12Z fines require dudp Pl plots on or above 'A' line name. symbol= to Atterberg limits plots shaded area, sod is a °PI plots below 'A' line. SW-SM well-graded sand with silt CL-Ml.., filly cloy. SW-SC well-graded sand with clay ,SP-Ski poorly graded sand with sUt SP-SC poorly graded sand with cloy 50 7, for aosofecotion of Me-grolned ode / and tore-gtolnod Welkin of moron fohed walla EaueUwi et'A'-the / Iwfmntd at M.4 to CL 1S.S. a. M.P1-0.73(LL-20) v,.r, OX\ touotlon of il'-fine •^�' • 40 Vrtm WOO et le to Ph), X Won PI.0.9(LL-!) /� G z 1. F 'e I- 4 � Q\. O1 4,,/ 01 20 • G�. MH ofi OH a. • la ,"i m /%///' ML or OL r I °0 IC 20 30 4a 50 60 70 s0 40 100 110 LIQUID LIMIT (LL) 411. N Not To Scale WELD COUNTY ROAD 86 51 41 42 r 0 n O z 21 . 3 4 21 O D 2 5 1 6 NW 1 /4 OF SECTION 6 T7N, R6 5W USDA SOIL CONSERVATION SERVICE SOIL GROUP MAP NEBARADO DEVELOPMENT • WELD COUNTY, COLORADO PROJECT NUMBER: 06-01 -148 DATE: AUGUST 2006 EARTH ENGINEERING COMPANY • 21—Dacono clay loam, 0 to 1 percent slopes. This is a deep, well drained soil on terraces at elevations of 4,550 to 4,970 feet. It formed in mixed alluvium. Included in mapping are small, long and narrow areas of sand and gravel deposits and some small leveled areas. Typically the surface layer of this Dacono soil is gray- ish brown clay loam about 12 inches thick. The subsoil is grayish brown clay loam about 15 inches thick. The sub- stratum is very gravelly sand. Permeability is moderately slow. Available water capacity is moderate. The effective rooting depth is 20 to 40 inches. Surface runoff is slow, and the erosion hazard is low. This soil is used almost entirely for irrigated crops. It is suited to all crops commonly grown in the area, includ- ing corn, sugar beets, beans, alfalfa, small grain, potatoes, and onions. An example of a suitable cropping system is 3 to -4 years of alfalfa followed by corn, corn for silage, sugar beets, small grain, or beans. Generally, such charac- teristics as a high clay content or a rapidly permeable substratum slightly restrict some crops. All methods of irrigation are suitable, but furrow ir- rigation is the most common. Proper irrigation water management is essential. Barnyard manure and commer- cial fertilizer are needed for top yields. Windbreaks and environmental plantings of trees and shrubs commonly grown in the area are generally well suited to this soil. Cultivation to control competing • vegetation should be continued for as many years as possible following planting. Trees that are best suited and have good survival are Rocky Mountain juniper, eastern redcedar, ponderosa pine, Siberian elm, Russian-olive, and hackberry. The shrubs best suited are skunkbush sumac, lilac, Siberian peashrub, and American plum. Openland wildlife, such as pheasant, mourning dove, and cottontail are best suited to this soil. Wildlife habitat development, including tree and shrub plantings and grass plantings to serve as nesting areas, should be suc- cessful without irrigation during most years. Under ir- rigation, good wildlife habitat can be established, benefit- ing, many kinds of openland wildlife. This soil has only fair potential for urban and recrea- tional development. Above the sand and gravel sub- stratum the soil has moderate to high shrink swell, low strength, and moderately slow permeability. These fea- tures create problems in dwelling and road construction. Excessive permeability in the substratum can cause con- tamination of the ground water supply from septic tank leach fields. Sewage lagoons need to be lined. Capability subclass IIs irrigated. • USDA SOIL CONSERVATION SERVICE SOIL GROUP DESCRIPTION DACONO SERIES EARTH FNCTNFPRTNa rnMPANY PERCOLATION TEST AREA /1 RESULTS PERCOLATION TEST AREA #2 RESULTS PERCOLATION TEST AREA /3 RESULTS • /1-- 6.0 MIN/NCH / 1-- 0.9 MIN/INCH /1-- 1,2 41N/INLH /2-- 5.0 YIN/INCH /2-- 0.6 YIN/INCH / 2-- 13.3 lMN/WCH /]-- 2.5 41N/INCH /3-- OT WN/INCH f 3-- 1.4 4IN/INCH N f A-- 2.7 MIN/INCH I 4-- 0.6 WN NCH f -- 0.9 FAIN/INCHf 5-- 3.6 41N/INCH /5-- 0.7 WNQNCH / 5-- 10.0 MN/NCH Not TO Scale /6-- 8.0 MIN/INCH /6-- 0.6 MIN/INCH / 6-- 4.0 MIN/INCH AVERAGE-- 5.0 MIN/INCH AVERAGE-- 0.7 MIN/INCH AVERAGE-- 5.1 MIN/INCH *A 3* B-9 B-3* *5.2* B-4* Q PCRCaAIq!1151 M7.4/3— � I *6 1* 0 // C.L F D 0 0 *. 3* J 8-8 W B-2-* *5.2* B-5* • PERCOLATOR R51 AREA *6 1* M C Q 0 z Z J O *4 3* U o B-7 MJi 8-1� *5.2* 8-6* PERCOLATION TEST AREA n O *6 1* LEGEND rB-1 BORING LOCATION SITE PHOTOS PHOTOS IMEN UOA APPRCOSAIE SAISM WCGld x wan 6 miaow BORING LOCATION DIAGRAM NEBARADO DEVELOPMENT • WELD COUNTY, COLORADO PROJECT NUMBER: 06-01-148 DATE: AUGUST 2006 EARTH ENGINEERING COMPANY ate. t Y • A ! � k y Y�l PHOTO # 1 • PHOTO # 2 NEBADRA DEVLOPMNT WELD COUNTYDO , COLORADO E • EEC PROJECT No. 06-01-148 E E AUGUST 2006 NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 06-01-148 DATE: AUGUST 2006 • LOG OF BORING B-1 RIG TYPE: CME45 SHEET I OF I WATER DEPTH FOREMAN: SM START DATE 8/8/2006 WHILE DRILLING None AUGER TYPE: C CFA FINISH DATE 8/8/2008 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None SOIL DESCRIPTION D N DU MC DD A-LIMITS -1W SWELL __ TYPE (FEET(BLOWS/T) JPSf �%) (PC�F 1_. LL__ _ PI_JY� PRESSURE M SOS PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of clay 1 SAND AND GRAVEL(SP-GP) 2 brown _ _ medium dense SS 3 18 -- 1.6 NL NP 5.5 4 dense _ _ SS 5 34 -- 2.6 6 _7_ 6 _9 SS 10 21 4500 6.1 FINE SAND(SP) _ _ • brawn 11 medium dense — — with a slight amount of clay 12 1-3 1-4 SS 1-5 22 2000 7.5 15.5 BOTTOM OF BORING 1-6 17 1-8 1-9 2-0 2-1 2-2 2-3 2-4 • 25 Earth Engineering Company NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 08-01.148 DATE: AUGUST2008 • LOG OF BORING B-2 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 8/8/2008 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 818/2006 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None SOIL DESCRIPTION 0 N au MC DO A-LIMITS -200 SWELL I TYPE IFEET_,JBLOW&FT) (FsB t_(%) LOF) LLR _MI PRESSURE X1p WO PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of clay 1 SAND AND GRAVEL(SP-GP) -2 brown _ _ dense 3 4 SS -6 3119" -- 1.8 B _7_ -8 _9 SS 1-0 18 3600 10.8 112.0 29 16 38.7 800 pef 0.1% CLAYEY SAND(SC) _ _ • brown medium —11— dense with calcareous deposits 12 1-3 1-4 with a slight amount of gravel _ _ . SS 16 18 1000 13.4 15.5'BOTTOM OF BORING 1-6 1-7 1-8 1-9 2-0 21 2-2 2-3 2-4 • 25 Earth Engineering Company NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 06-01-148 DATE: AUGUST 2006 • LOG OF BORING B-3 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 818/2006 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 8/8/2009 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None SOIL DESCRIPTION o N OU MC DO M4M119 -200 SWELL TYPE (FEET) (BLOWS/FS) tEF (%) 1PCS) .1 PI 14) PRESSUE@AW PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of clay 1 SAND AND GRAVEL(SP-GP) -2 brown _ _ medium dense SS 3 17 — 2.3 _4 dense — — SS 5 33 -- 2.7 6 _7 6 _9 5S 1-0 10 1500 10.9 • FINE SAND(SP) 1-1— brown medium dense 12 with a slight amount of clay and gravel _ _ 13 1-4 55 1-5 18 1000 9.4 15.5'BOTTOM OF BORING 1-6 1-7 1-8 1-9 2-0 2-1 2-2 2-3 2-4 • 25 _ Earth Engineering Company NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 06-01-148 DATE: AUGUST2008 • LOG OF BORING BA RIG TYPE: CME46 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 6/8/2005 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 8/8/2006 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None SOIL DESCRIPTION o u Ou MC DO A-UWTS -200 SWELL TYPE IFEETI DLILOW61F�_,_(PS) �J (PCFI_,. LL PP (%I PRESSURS0U PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of day 1 SAND AND GRAVEL(SP-GP) 2 brown _ _ dense 3 4 SS -6 36 — 1.8 _9 _ _ 7 _9 SS 1-0 33/9" - 2.0 1-1 • 12 1-3 FINE SAND(SP) — — brown 14 medium dense _ _ with a slight amount of day SS 16 18 600 7.2 15.5'BOTTOM OF BORING 1-6 1-7 1-8 1-9 20 2-1 2-2 2-3 2-4 2-6 Earth Engineering Company • NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 08-01-148 DATE: AUGUST 2006 • LOG OF BORING B-6 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 8/6/2006 WHILE DRILLING None AUGER TYPE: C CFA FINISH DATE 8/8/2006 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None SOIL DESCRIPTION o N 0U MC 00 A-UMFTS a00 SWELL IYPE (FEET) (BLOWa6TIPSF) _ l%J IPCFI LL PI S%) .PRESSURE %f2 Fa0PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of clay 1 SAND AND GRAVEL(SP-GP) -2 brown _ _ medium dense CS 3 23 -- 1.5 _4_ dense _ _ SS 5 3619" -- 1.2 6 _7_ B _9 SS 1-0 23 -- 1.7 • FAT CLAY(CH) -1-1_ greygrey/brown/oliveolivolive stiff 12 with a slight amount of gravel 13 1-4 CS 15 15 4600 26.7 98.6 66 47 97.7 2400 pet 1.7% 15'BOTTOM OF BORING _ _ 16 1-7 1-8 1-9 2-0 21 2-2 2-3 2-4 • 25 Earth Engineering Company • NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 08-01-148 DATE: AUGUST2008 • LOG OF BORING 6-e RIG TYPE: CME45 SHEET I OF I WATER DEPTH FOREMAN: SM START DATE 8/8/2008 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 8/8/2006 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 5 DAYS AFTER DRILLING None SOIL DESCRIPTION o N DU MC DO A4JMITS -200 SWELL _ I TYPE (FEET9LOWSIFTf PS its (PDFL`LL PI (� __ (141 PRESSURE 141 S00 PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of clay 1 SAND AND GRAVEL(SP-GP) -2 brown _ _ dense 3 _4 SS -5 31 — 1.9 6 _7_ B _9 SS 1-0 10 1000 16.0 113.7 900 pef 0.3% • FAT CLAY(CH) _1-1_ gray brown medium stiff 12 13 14 CLAYEY SAND(SC) _ _ brown SS 15 41/11" 7000 11.9 dense with a slight amount of gravel _ _ 15.5 BOTTOM OF BORING 16 1-7 1-3 1-9 2-0 2-1 2-2 2-3 2-4 • 25 Earth Engineering Company NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 06-01-148 DATE: AUGUST 2006 • LOG OF BORING B-7 RIG TYPE: CM E45 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 8/8/2008 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 8/8/2006 AFTER DRILLING None SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None SOIL DESCRIPTION o N 0u MC DO A4JMITS -200 SWELL TYPE (FEET) (BLOWS/FT) Of SF) % PC LL PI PRESSURE %R EOOPSF SAND AND GRAVEL(SP-GP) _ _ dark brown wtth a slight amount of clay 1 SAND AND GRAVEL(SP-GP) -2 brown _ _ 3 _4_ 5 6 _7 a 8'BOTTOM OF BORING _ _ 9 1-0 • 1-1 12 1-3 14 15 1-6 17 1-8 1-9 2-0 2-1 2-2 23 2-4 • 25 Earth Engineering Company NEBARADO DEVELOPMENT WELD COUNTY,COLORADO PROJECT NO: 06-01-148 DATE: AUGUST2006 • LOG OF BORING B-6 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: SM START DATE 8/6/2006 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 8/8/2006 AFTER DRILLING None SPT HAMMER: AUTO SURFACEELEV N/A 24 HOUR None SOIL DESCRIPTION o N aU MC 00 A-UMIrS -m0 SWELL TYPE (FEET) (BLOWSRT) PSI FI 1%1 JPCF) LL _PI 6N PRESSURE %S'<We PSF SAND AND GRAVEL(SP-GP) _ _ dark brown with a slight amount of clay 1 SAND AND GRAVEL(SP-GP) -2 brown _ _ 3 4 -6 6 8 8'BOTTOM OF BORING _ _ 9 10 • 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 2-0 21 2-2 2-3 2-4 • 25 Earth Engineering Company • SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Clayey Sand Sample Location: B-2, S-2 @ 9' Liquid Limit: 29 (Plasticity Index: 15 I % Passing #200: 38.7 Beginning Moisture: 10.3% Dry Density: 112.0 pcf 'Ending Moisture: 16.1% Swell Pressure: 800 psf % Swell @ 500 psf: 0.1% 10 8 6 U) 4 2 cc Wate"Added a. -2 c 0 co •II_ O -6 O U -8 -10 0.01 0.1 1 10 Load (TSF) • Project: Nebarado Development ; Weld County, Colorado EEC l Project No.: 06-01-148 7 Date: August 2006 _ _ _ 4 SWELL / CONSOLIDATION TEST RESULTS • Material Description: Grey/Brown/Olive Fat Clay Sample Location: B-5, S-4 @ 14' Liquid Limit: 66 IPlasticity Index: 47 I % Passing #200: 47 Beginning Moisture: 25.8% Dry Density: 98.6 pcf 'Ending Moisture: 26.1% Swell Pressure: 2400 psf % Swell @ 500 psf: 1.7% 10 8 38 co 4 t 2 • a Water Added a -2 c-4 0 0 c-6 O U -8 10 0.01 0.1 1 10 Load(TSF) Project: Nebarado Development • Weld County, Colorado ' EEC 1 ) Project No.: 06-01-148 Date: August 2006 SWELL / CONSOLIDATION TEST RESULTS Material Description: Grey/Brown Fat Clay Sample Location: B-6, S-2 @ 9' Liquid Limit: -- (Plasticity Index: -- 1 % Passing #200: — Beginning Moisture: 15.3% Dry Density: 113.7 pcf 'Ending Moisture: 15.2% Swell Pressure: 900 psf % Swell @ 500 psf: 0.3% 10 I I I III I . 8 6 co 4 c 2 • 0 c WateAdded a. -2 c -4 co O 2 -6 c 0 U -8 -10 1 0.01 0.1 1 10 Load (TSF) Project: Nebarado Development • Weld County, Colorado EEC ) Project No.: 06-01-148 Date: August 2006 • REFERENCES 1. Colton R.B. and Harold R. Fitch, 1974, Map Showing Potential Sources of Gravel and Crushed-Rock Aggregate,in the Boulder-Fort Collins-Greeley Area,Front Range Urban Corridor, Colorado: U.S. Geological Survey Miscellaneous Investigation Series Map I-855-D. 2. Colton R.B., Holligan, J.A., and Anderson, L.W., 1975, Preliminary Map of Landslide Deposits, Greeley 1°x2° Quadrangle, Colorado: U.S. Geological Survey Miscellaneous Investigation Series Map MF-704. 3. McCain,J. and Hotchkiss,W.R., 1975,Map Showing Flood-Prone Areas,Boulder- Fort Collins-Greeley Area,Front Range Urban Corridor,Colorado:U.S.Geological Survey Miscellaneous Investigation Series Map I-855-E. 4. Colton R.B., 1978, Geologic Map of the Boulder-Fort Collins-Greeley Area, Colorado:U.S.Geological Survey Miscellaneous Investigation Series Map I-955-G. 5. Hershey L.A. and Schneider, Jr. P.A., 1972, Geologic Map of the Lower Cache La Poudre River Basin,North-Central Colorado:U.S.Geological Survey Miscellaneous Investigation Series Map I-687. 6. Hillier D. and Schneider, Jr. P.A., 1979, Depth to the Water Table in the Boulder- Fort Collins-Greeley Area,Front Range Urban Corridor,Colorado:U.S. Geological Survey Miscellaneous Investigation Series Map I-855-I. 7. United States Department of Agriculture Soil Conservation Service in Cooperation with Colorado Agricultural Experiment Station, 1980, Soil Survey of Weld County, Colorado (Southern PartO, Sheet 3 of 35. • • FINAL DRAINAGE REPORT FOR MACICEY CIRCLE PUD June 3,2008 Prepared for: Gary Mackey 6804 Aaron Drive • Fort Collins, CO 80524 Prepared by: Mary Mateo,EI Stewart& Associates,Inc. PO Box 429 103 S.Meldrum St. Fort Collins, CO 80521 Phone: (970) 482-9331 Fax: (970)482-9382 • EXHIBIT CERTIFICATION • I hereby certify that this report for the final drainage design of Mackey Circle was prepared by me (or under my direct supervision) in accordance with the provisions of the Code of Weld County, Colorado, for the owners thereof i,�, ►�� , ®v ��e� Foq��.i `r' :aiseies Kevin Forbes o's1 Aar Registered Professiona - � State of Colorado No. 35265 • • • TABLE OF CONTENTS PAGE I. GENERAL LOCATION AND DESCRIPTION A. SI l'E LOCATION 3 B. DESCRIPTION OF PROPERTY 3-4 II. DRAINAGE BASINS AND SUB-BASINS A. MAJOR BASIN DESCRIPTION 4 B. SUB-BASIN DESCRIPTION 4-6 III. DRAINAGE DESIGN CRITERIA A. REGULATIONS 6 B. HYDROLOGICAL CRITERIA 6 C. HYDRAULIC CRITERIA 6 IV. DRAINAGE FACILITY DESIGN 6-7 VI. CONCLUSIONS 7 VII. REFERENCES 8 VIII. APPENDICES 9 • I. GENERAL LOCATION AND DESCRIPTION • A. Location Mackey Circle PUD (Project Site) is located in the northwest quarter of Section 6, Township 7 North, Range 65 West of the 6th Principal Meridian, County of Weld, State of Colorado. The Site lies approximately 1.5 miles east of Highway 85, northeast of the town of Ault, and approximately one-quarter mile south of the intersection of Weld County Roads 37 and 86. The Site is bounded on the North by a private residence on a lot of approximately ten acres, on the West by Weld County Road Number 37, and on the East and South by undeveloped farmland. There are no developments within one-half mile surrounding the proposed subdivision. A Vicinity Map is provided in the Appendix. B. Description of Property The total Site area is approximately 27.0 acres. There is an access easement along the southwest boundary of the Site. An undeveloped • dirt "road" exists within this area and continues to the east. The Site currently drains to the south and east, with slopes ranging from 0 to 1 percent, and outfalls to a ditch along the north side of the undeveloped "road". This ditch leads to an irrigation pond on a private lot east of the Site. Upon overtopping, this ditch drains southward in an existing ditch, ultimately draining to the roadside at County Road 84. The Project Site is currently zoned PUD for six lots with (E) Estate Uses. This project proposes to develop six single-family dwellings. Anticipated construction will consist of over-lot grading, and construction of infrastructure, including underground utilities, asphalt street, and the aforementioned dwelling units. Detention will be provided at the southeast corner of the Site. There are several irrigation facilities in the area. The Site is surrounded by farmland, and all runoff ultimately ends up in roadside ditches and is utilized for agricultural purposes. The irrigation facilities are privately owned and maintained, and are not associated • with a ditch company. Development of this Site will not affect any of • the surrounding irrigation facilities. Soil classifications for the Site are made up of Dacono clay loam (0- 1% slopes) and Nunn clay loam (0-1% slopes). See the Soil Conservation map and descriptions provided in the Appendix. These soils belong to the hydrologic soil group C, as assigned by the Natural Resources Conservation Service. They are deep and well drained, with moderately slow permeability. Surface runoff is slow, and the erosion hazard is low. II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description A portion of the Site is shown within the 100-year FEMA regulatory floodplain boundary on the current effective FEMA Flood Insurance Rate Map —Community Panel Number 080266 0480 C dated September 28, 1982 (See F1RMette in Appendix). The floodplain • boundary is also included on the existing and proposed drainage maps that are part of this report. The Site does not lie within any basin identified with the South Weld I-25 Corridor Master Drainage Plan. A previous drainage study was done for this Site in processing for change of zone. There are changes to that study, mainly related to the plans for detention of developed flows from the Site. There are no wetlands associated with the Site. B. Sub-Basin Description The historic drainage patterns for this site are those that currently exist, as the Site is undeveloped. As previously stated, the entire Site historically drains to the southeast, with runoff sheet-flowing to a ditch along the southern boundary of the property. As previously stated, those flows are directed to a pond on a private lot east of the Site and ultimately to the roadside of County Road 84 in a major event. The only offsite flows are those that enter the Site from the north (basin OS 1). Existing drainage conditions and surface runoff • are shown on the provided Existing Drainage Conditions Map. 4 • Developed Sub-basins The proposed site was divided into four basins. Offsite basins 1-OS and 2-OS consist of undeveloped property that drains onto the Site from the north. Those flows were calculated concentrated at Design Points (DP) 3 and 5 along the northern boundary of the Site. Sub-basin A includes the proposed road ZVlackey Circle;its roadside swales and portions of the fronts of lots 3-6. This basin drains, via the roadside swales, to DP1, where the roadside swales meet at the south end of the cul-de-sac and are directed southward to DP2 and the detention area at the southeast corner of the Site. Sub-basin B includes Lots 1 and 2 and their adjacent halves of County Road 37. This basin drains in a southeast direction to DP2, where v flows join those from sub-basin A. A swale along the southern boundary will insure that flows are directed eastward to the detention • area. Sub-basin C includes a portion of County Road 37 adjacent to Lot 6, as well as portions of Lots 3-6 that drain to the southeast. A swale will be constructed along the floodplain boundary to direct these developed flows to the detention area. Sub-basin D is that portion of the Site that lies within the 100-year floodplain, in addition to the northeast corner of the Site. As there is no development anticipated in this area, no detention is being provided for it. Flows will be directed via swale along the eastern boundary of the Site, and then to the swale that will carry release flows from the detention area to the east, which is the historical outfall for the Site. There is currently no onsite detention provided for the Site. This project proposes to construct a detention area along the southern boundary of the Site. This area will detain developed runoff from the Site, and offsite flows will be passed through at their historic rates. • 5 Runoff will be conveyed overland and via swales to the detention area • and released via storm pipe to the east. III. DRAINAGE DESIGN CRITERIA A. Regulations This preliminary analysis of the storm drainage system for this project was prepared in accordance with the criteria set forth in the Weld County Code, Weld County Storm Drainage Criteria, and the Urban Drainage and Flood Control District's Urban Storm Drainage Criteria Manual (USDCM). B. Hydrological Criteria 1. Design Rainfall NOAA Atlas 2 Data converted to Intensity-Duration-Frequency Curves for the Site 2. Runoff Method Rational • 3. Design Storms a. Minor 5-year b. Major 100-year 4. Detention/ Storage Method Modified FAA C. Hydraulic Criteria The necessary pond volume was calculated utilizing Urban Drainage spreadsheets and the Modified FAA method. Water Quality will be provided, with the Catchment Volume being considered a portion of the total 100-year volume. The total required volume is 2.5 acre-feet. The pond outlet will be designed to drain in no less than 72 hours, per Weld County Code. ; ituv-,, IV. DRAINAGE FACILITY DESIGN The intent of the proposed drainage system is to safely convey the 5- year (minor) and 100-year (major) design storm runoff. Runoff will • be conveyed overland and by surface drainage structures, i.e. swales. 6 Existing drainage patterns will be maintained and utilized as • practicality permits. The general pattern of flow is toward the south and east. The pond's outlet pipe will be located at the southeast corner. The pond release rate will be 6.66 cfs —the historic five-year rate of 3.12 cfs for its onsite tributary area, in addition to the historic flow from offsite basin 1-OS (3.54 cfs for the 100-year storm). Drainage easements for public and private drainage infrastructure will be provided in accordance with the appropriate regulations. The proposed drainage and detention facilities will be privately owned and maintained. Weld County will not be responsible for the maintenance of drainage-related facilities. Agreements will be provided for the release of flows east of the Site.4- Erosion control measures will be utilized to mitigate erosion and control sediment. Standard Best Management Practices will include, but are not limited to, perimeter silt fencing, vehicle tracking control, inlet and outlet protection, and permanent seeding. V. CONCLUSIONS A portion of the Site lies within the 100-year FEMA regulatory floodplain, and therefore, no fill or above-ground construction can occur within that boundary. Finished floor elevations will be a minimum 2 feet above adjacent highest grade for each lot. The analysis and design of the storm drainage system for this project was prepared in accordance with the criteria set forth in the Weld County Code and the USDCM. No adverse affects to surrounding properties are anticipated from the development of this site. The design, if properly maintained and constructed, will convey, release and protect the quality of storm water runoff up to and including the 100-year storm event in a safe manner to protect life and limit damage to property. • • VI. REFERENCES 1. Urban Storm Drainage Criteria Manual Volumes 1 and 2, Urban Drainage and Flood Control District, June 2001, and Volume 3, September 1999. 2. Weld County Code, Colorado Code Publishing Company, 2001. 3. Soil Survey of Weld County, Colorado, Southern Part, U.S. Department of Agriculture, Soil Conservation Service and Forest Service, December, 1980. 4. Flood Insurance Rate Map No. 080266 0480 C, Federal Emergency Management Agency, National Flood Insurance Program, September 28, 1982. • 5. NOAA Atlas 2 Precipitation-Frequency Atlas of the Western United States, Volume III Colorado, U.S. Department of Commerce, J.F. Miller, R.H. Frederick, and R.J. Tracey, 1973. 6. Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manual— Volumes 1, 2, and 3, Weld County Public Works Department, October, 2006. 8 WI. APPENDICES • 1. Vicinity Map Soils Data FIRMette 2. Historic Storm Drainage Calculations 3. Proposed Storm Drainage Calculations _ 4. Historic Drainage Map (insert) Proposed Drainage Map (insert) • • MACKEY CIRCLE, P . U . D . VICINITY MAP SCALE — 1"=2000' 36 31 32 Weld County Road No. 86 a, ii M N. O O Z Z a -o a O • O O a' O ce 1 c i .� 5 o °o°, r 0 0%.,6 0 T) v 3 Weld County ad . 84 12 7 8 i 1 U. S. 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Y v ✓r'Vii t x y.�a f ar. f Vi ja�'�"' - T' dF 'ar A ..mo Et +V'` a �.W t' - Ea g . { et 's i�e�ppa ,,"^�. .y t' aF 'S,rx`e r..1,-. ..:- f i ;� #t-+r `]r y t?4 fix' E� r i t t a �..rt o, "zE �Rts' t '".�. t Fr , -t ₹ -:: a •: .£f?-, ' s- \ a ₹r's 1 f<y" is°fi ` r g.4-7 �'-E' -t �§o- srt H ,e.s & aar L z .e s t�- `r. ;!�* 74 t �'� a d' Ste. 1`47!;:cciw ;Mist r _•- a r : z v s•ti ' •cea b ti- £ . • WELD COUNTY, COLORADO, SOUTHERN PART 17 Typically the surface layer of this Colombo soil is dark Wildlife is an important secondary use of this soil. The i ayish brown clay loam about 14 inches thick. The upper cropland areas provide favorable habitat for ring-necked es of the underlying material is pale brown pheasant and mourning dove. Many nongame species can stx ed clay loam and loam. The lower part to a depth be attracted by establishing areas for nesting and escape 60 inches is very pale brown loam stratified with thin cover. For pheasants, undisturbed nesting cover is essen- ises of fine sand, medium sand, and clay loam. tial and should be included- in plans for habitat develop- Permeability is moderate. Available water capacity is ment, especially in areas of intensive agriculture. Range- "";h. The effective rooting depth is 60 inches or more. land wildlife, for example, the pronghorn antelope, can be irface runoff is medium, and the erosion hazard is low. attracted by developing livestock watering facilities, In irrigated areas this soil is suited to all crops corn- managing livestock grazing, and reseeding where needed. Where this soil is on flood plains and is susceptible to monly grown in the area, including corn, sugar beets, flooding, it has poor potential for urban and recreational pans, alfalfa, small grain, potatoes, and onions. An exam- development. On the higher terraces, potential is fair. e of a suitable cropping system is 3 to 4 years of alfalfa Dwelling and road designs may need to be modified to •followed by corn, corn for silage, sugar beets, small grain, compensate for the limited capacity of this soil to support or beans. Land leveling, ditch lining, and installing a load and to protect it against frost action. Capability pelines may be needed for proper water application. subclass Ile irrigated, IIIe nonirrigated; Clayey Plains All methods of irrigation are suitable, but furrow ir- range site. rigation is the most common. Barnyard manure and corn- 21—Dacono clay loam, 0 to 1 percent slopes. This is a —ercialfertilizer are needed for top yields. deep, well drained soil on terraces at elevations of 4,550 In nonirrigated areas this soil is well suited to winter to 4,970 feet. It formed in mixed alluvium. Included in -wheat, barley, and sorghum if it is summer fallowed in al- mapping are small, long and narrow areas of sand and ternate years. Winter wheat is the principal crop. The gravel deposits and some small leveled areas. redicted average yield is 33 bushels per acre. If the crop Typically the surface layer of this Dacono soil is gray- winterkilled, spring wheat can be seeded. Generally ish brown clay loam about 12 inches thick. The subsoil is precipitation is too low for beneficial use of fertilizer. grayish brown clay loam about 15 inches thick. The sub- Stubble mulch farming, striperopping, and minimum til- stratum is very gravelly sand. ,ge are needed to control soil blowing and water erosion. Permeability is moderately slow. Available water _erracing also may be needed to control water erosion. capacity is moderate. The effective rooting depth is 20 to The potential native vegetation is dominated by 40 inches. Surface runoff is slow, and the erosion hazard •rn wheatgrass. Blue grama, switchgrass, sand is low. ass, big bluestem, slender wheatgrass, indiangrass, This soil is used almost entirely for irrigated crops. Iteen needlegrass are also present. Potential produc- is suited to all crops commonly grown in the area, includ- tion ranges from 1,000 pounds per acre in favorable years ing corn, sugar beets, beans, alfalfa, small grain, potatoes, 600 pounds in unfavorable years. As range condition and onions. An example of a suitable cropping system is 3 eteriorates, the tall grasses decrease, blue grama and to 4 years of alfalfa followed by corn, corn for silage, buffalograss increase, and forage production drops. Un- sugar beets, small grain, or beans. Generally, such charac- 'esirable weeds_-and_annualssnvade_the site and erosion teristics as a high clay content or a rapidly permeable an occur as range condition becomes poorer. substratum slightly restriet-some crops— ---- Management of vegetation on this soil should be based All methods of irrigation are suitable, but furrow ir- on taking half and leaving half of the total annual produc- rigation is the most common. Proper irrigation wateral. Barnyard manure and commer- on. Seeding is desirable if the range is in poor condition. management is essenti Vestern wheatgrass, switchgrass, sand reedgrass, cial fertilizer are needed for top yields. Windbreaks and environmental plantings of trees and sideoats grama, pubescent wheatgrass, intermediate shrubs commonly grown in the area are generally well wheatgrass, and blue grama are suitable for seeding. The MSS selected should meet the seasonal requirements of suited to this soil. -Cultivation to control competing vegetation should be continued for as many years as _vestock. It can be seeded into a firm prepared seedbed. possible following planting. Trees that are best suited and A grass drill should be used. Seeding early in spring has have good survival are Rocky Mountain juniper, eastern raven most successful. redcedar, ponderosa pine, Siberian elm, Russian-olive, and Windbreaks and environmental plantings of trees and hackberry. The shrubs best suited are skunkbush sumac, shrubs commonly grown in the area are generally well lilac, Siberian peashrub, and American plum. suited to this soil. Cultivation to control competing Openland wildlife, such as pheasant, mourning dove, egetation should be continued for as many years as and cottontail are best suited to this soil.Wildlife habitat ossible following planting.Trees that are best suited and development, including tree and shrub plantings and have good survival are Rocky Mountain juniper, eastern grass plantings to serve as nesting areas, should be sue- -edcedar, ponderosa pine, Siberian elm, Russian-olive, and cessful without irrigation during most years. Under ir- iackberry. The shrubs best suited are skunkbush sumac, rigation, good wildlife habitat can be established, benefit- -.Siberian peashrub, and American plum. ing, many kinds of openland wildlife. • 18 SOIL SURVEY . This soil has only fair potential for urban and recrea- prepared seedbed. Seeding early in spring has pro tional development. Above the sand and gravel sub- most successful. stratum the soil has moderate to high shrink swell, low Windbreaks and environmental plantings of trees strength, and moderately slow permeability. These fea- shrubs commonly grown in the area are generally 1 tures create problems in dwelling and road construction. suited to this soil. Cultivation to control compel Excessive permeability in the substratum can cause con- vegetation should be continued for as many years tamination of the ground water supply from septic tank possible following planting. Trees that are best suited leach fields. Sewage lagoons need to be lined. Capability have good survival are Rocky Mountain juniper, east subclass IIs irrigated. reced22—Dacono clay loam, 1 to 3 percent slopes. This is a hack ear, ponderosa pine, Siberian elm, Russian-olive, hrubs best suited are sku deep, well drained soil on terraces at elevations of 4,550 lilac, Siberian pe. The ashrub, and American plmnkbush sun to 4,970 feet. It formed in mixed alluvium. Included in Openland wildlife, such as pheasant, mourning do mapping are small, long and narrow areas of sand and and cottontail, are best suited to this soil. Wildlife habi gravel deposits and some small leveled areas. development, including tree and shrub plantings a Typically the surface layer of this Dacono soil is gray- grass plantings to serve as nesting areas, should be si ish brown clay loam about 12 inches thick. The subsoil is cessful without irrigation during most years. Under grayish brown clay loam about 15 inches thick. The sub- rigation, good wildlife habitat can established, benefiti — stratum is very gravelly sand. many kinds of openland wildlife. Rangeland wildlife, 1 Permeability is moderate] y slow. Available_ water_._example,--the pronghorn antelope,can be attracted -capacity is moderate. The effective rooting depth is 20 to developing livestock watering facilities, managi 40 inches. Surface runoff is medium, and the erosion livestock grazing, and reseeding where needed. hazard is low. This soil has In irrigated areas this soil is suited to all crops com- tional development. Abov fair epotentialurban and gravel su monly grown in the area, including corn, sugar beets, stratum the soil has a moderate to high shr nk-swi beans, alfalfa, small grain, potatoes, and onions. An exam- potential, low strength, perme ple of a suitable cropping system is 3 to 4 years of alfalfa These features create problems in dwelling and ro followed by corn, corn for silage, sugar beets, small grain, struction. Excessive permeability in the substratum CE or beans. Generally, such characteristics as a high clay cause contamination of the ground water supply fro content or a rapidly permeable substratum slightly septic tank leach fields. Sewage lagoons need to be line restrict some crops. Capability subclass IIe irrigated, IIIc nonirrigate, All methods of irrigation are suitable, but furrow ir- Clayey Plains range site. rigation is the most common. Proper irrigation water 23—Fort Collins loam, 0 to 1 percent slopes. This is management is essential. Barnyard manure and commer- deep, well drained soil on terraces and smooth plains a cial fertilizer are needed for top yields. In nonirrigated areas most of the acreage is in small modified odations of 4,500 to 5,050 ep feet. It formed in mappinga ar grain and is summer fallowed in alternateyears. Winter ly evthie eolian deposits.few csmall in ar some h small leveled areas and small areas of a soi wheat is the principal crop. The predicted average yield is that is calcareous at the surface. 33 bushels per acre. If the crop is winterkilled, spring Typically the surface layer of this Fort Collins soil I wheat can be seeded. Generally precipitation is too low grayish brown loam about 10 inches thick. The subsoil is for beneficial use of fertilizer. Stubble mulch farmin stri cro brown and very pale brown clay loam and loam about 2( g,, p pping, and minimum til- inches thick. The substratum to a depth of 60 inches u lage are needed to control soil blowing and water erosion. fine sandy loam. The potential native vegetation is dominated by Permeability is moderate. Available water capacity h western wheatgrass and blue grama. Buffalograss is also high. The effective rooting depth is 60 inches or more. present. Potential production ranges from 1,000 pounds Surface runoff is slow, and the erosion hazard is low. per acre in favorable years to 600 pounds in unfavorable This soil is used almost entirely for irrigated crops. It years. As range condition deteriorates, a blue grama-buf- is suited to all crops commonly grown in the area, includ- falograss sod forms. Undesirable weeds and annuals in- ing corn, sugar beets, beans, alfalfa, small grain, potatoes, vade the site as range condition becomes poorer. and onions. An example of a suitable cropping Management of vegetation on this soil should be basedyarso corn, corn system ige on taking half and leaving half of the total annual produc- sugar beets, small gra f, or beds. w c for silage, tion. Range pitting can help in reducing grain, or top yields.Few conservation prac- desirable if the range is in runoff Seeding is liens are needed to maintain top g poor condition. Western All methods of irrigation are suitable, but furro wheatgrass, blue grama, sideoats grama, buffalograss, pu- rigation is the most common. Barnyard manure and co bescent wheatgrass, and crested wheatgrass are suitable mercial fertilizer are needed for top yields. for seeding. The grass selected should meet the seasonal Windbreaks and environmental plantings of trees and firmisorghumostubbleoor it can be driledinto a c firm suited tomhsnlsor�oCultiv Cultivation ontolncompeting 28 SOIL SURVEY eiv40—Nunn loam, 1 to 3 percent slopes. This is a deep, vegetation should be continued for as many years as ell drained soil on terraces at elevations of 4,550 to 5,000 possible following planting. Trees that are best suited and feet. It formed in mixed alluvium. Included in mapping have good survival are Rocky Mountain juniper, eastern are small, long and narrow areas of sand and gravel redcedar, ponderosa pine, Siberian elm, Russian-olive, and deposits and small areas of soils that are subject to occa- hackberry. The shrubs best suited are skunkbush sumac, sional flooding. Some leveled areas are also included. lilac, Siberian peashrub, and American plum. Typically the surface layer of this Nunn soil is grayish Wildlife is an important secondary use of this soil. The brown loam about 12 inches thick. The subsoil is light cropland areas provide favorable habitat for ring-necked brownish gray clay loam about 12 inches thick. The upper pheasant and mourning dove. Many nongame species can part of the substratum is light brownish gray clay loam. be attracted by establishing areas for nesting and escape The lower part to a depth of 60 inches is brown sandy cover. For pheasants, undisturbed nesting cover is essen- loam. tial and should be included in plans for habitat develop- Permeability is moderately slow. Available water ment, especially in areas of intensive agriculture. Range- capacity is high. The effective rooting depth is 60 inches land wildlife, for example, the pronghorn antelope, can be or more. Surface runoff is medium, and the erosion attracted by developing livestock watering facilities, hazard is low. managing livestock grazing, and reseeding where needed. In irrigated areas this soil is suited to all crops com- This soil has fair to poor potential for urban develop- monly grown in the area, including corn, sugar beets, ment. It has moderate to high shrink swell, low strength, beans, alfalfa, small grain, potatoes, and onions. An exam- and moderately slow permeability. These features create ple of a suitable cropping system is 3 to 4 years of alfalfa problems in dwelling and road construction. Those areas followed by corn, corn for silage, sugar beets,small grain, that_have_.Joam_.or_sandy_loam_irl_the_laiver part-.of--the_- or beans. Generally such characteristics as a high clay substratum are suitable for septic tank absorption fields content or a rapidly permeable substratum slightly and foundations. Some areas of this soil are adjacent to restrict some crops. streams and are subject to occasional flooding. The poten- All methods of irrigation are suitable, but furrow ir- tial is fair for such recreational development as camp and rigation is the most common. Proper irrigation water picnic areas and playgrounds. Capability subclass Ile ir- management is essential. Barnyard manure and commer- rigated, IIIc nonirrigated; Loamy Plains range site. cial fertilizer are needed for top yields. 41—Nunn clay loam, 0 to 1 percent slopes. This is a * IIIMost nonirrigated areas are used for small grain. The deep, well drained soil on terraces and smooth plains at oil is summer fallowed in alternate years. Winter wheat elevations of 4,550 to 5,150 feet. It formed in mixed allu- is the principal crop. If the crop is winterkilled, spring vium and eolian deposits. Included in mapping are small, wheat can be seeded. Generally precipitation is too low long and narrow areas of sand and gravel deposits and for beneficial use of fertilizer. small areas of soils that are subject to occasional flooding. Such practices as stubble mulch farming, striperopping, Some small leveled areas are also included. and minimum tillage are needed to control soil blowing Typically the surface layer of this Nunn soil is grayish and water erosion. brown clay loam about 9 inches thick. The subsoil is light The potential native vegetation is dominated by blue brownish gray clay loam about 14 inches thick. The upper grama. Several mid grasses, such as western wheatgrass part of the substratum is clay loam. The lower part to a and needleandthread, are also present. Potential produc- depth of 60 inches is sandy loam. tion ranges from 1,600 pounds per acre in favorable years Permeability is moderately slow. Available water to 1,000 pounds in unfavorable years. As range condition capacity is high. The effective rooting depth is 60 inches deteriorates, the mid grasses decrease; blue grama, buf- or more. Surface runoff is slow, and the erosion hazard is falograss, snakeweed, yucca, and fringed sage increase; low. and forage production drops. Undesirable weeds and an- This soil is used almost entirely for irrigated crops. It nuals invade the site as range condition becomes poorer. is suited to all crops commonly grown in the area, includ- Management of vegetation on this soil should be based ing corn, sugar beets, beans, alfalfa, small grain, potatoes, on taking half and leaving half of the total annual produc- and onions. An example of a suitable cropping system is 3 tion. Seeding is desirable if-the range is in poor condition. to 4 years of alfalfa followed by corn, corn for silage, Sideoats grama, little bluestem, western wheatgrass, blue sugar beets, small grain, or beans. Few conservation prac- - grama,pubescent wheatgrass, and crested wheatgrass are tices are needed to maintain top yields. suitable for seeding. The grass selected should meet the All methods of irrigation are suitable, but furrow ir- seasonal requirements-of livestock. It can be-seeded-into- rigation is the-most common.Barnyard-manure-and com- a clean, firm sorghum stubble, or it can be drilled into a mercial fertilizer are needed for top yields. firm prepared seedbed. Seeding early in spring has Windbreaks and environmental plantings of trees and proven most successful. shrubs commonly grown in the area are generally well ilkWindbreaks and environmental plantings of trees and suited to this soil. Cultivation to control competing rubs commonly grown in the area are generally well vegetation should be continued for as many years as suited to this soil. Cultivation to control competing possible following planting. Trees that are best suited and WELD COUNTY, COLORADO, SOUTHERN PART 29 have good survival are Rocky Mountain juniper, eastern The potential native vegetation is dominated by redcedar, ponderosa pine, Siberian elm, Russian-olive, and western wheatgrass and blue grams. Buffalograss is hackberry. The shrubs best suited are skunkbush sumac, present. Potential production ranges from 1,000 po lilac, Siberian peashrub, and American plum. per acre in favorable years to 600 pounds in unfavora e Wildlife is an important secondary use of this soil. The years. As range condition deteriorates, a blue grama-buf- cropland areas provide favorable habitat for ring-necked falograss sod forms. Undesirable weeds and annuals in- pheasant and mourning dove. Many nongame species can vade the site as range condition becomes poorer. be attracted by establishing areas for nesting and escape Management of vegetation of this soil should be based cover. For pheasants, undisturbed nesting cover is essen- on taking half and leaving half of the total annual produc- tial and should be included in plans for habitat develop- tion. Range pitting can help in reducing runoff. Seeding is ment, especially in areas of intensive agriculture. desirable if the range is in poor condition. Western This soil has fair to poor potential for urban develop- wheatgrass, blue grama, sideoats grama, buffalograss, pu- ment. It has moderate to high shrink swell, low strength, bescent wheatgrass, and crested wheatgrass are suitable and moderately slow permeability. These features create for seeding. The grass selected should meet the seasonal problems in dwelling and road construction. Those areas requirements of livestock. It can be seeded into a clean, that have loam or sandy loam in the lower part of the firm sorghum stubble, or it can be drilled into a firm substratum are suitable for septic tank absorption fields prepared seedbed. Seeding early in spring has proven and foundations. Some areas of this soil are adjacent to most successful. streams and are subject to occasional flooding. The poten- Windbreaks and environmental plantings are generally tial is fair for such recreational development as camp and well suited to this soil. Cultivation to control competing picnic areas and playgrounds. Capability class I irrigated. vegetation should be continued for as many years as 42—Nunn clay loam, 1 to 3 percent slopes. This is a possible following planting. Trees that are best suited and deep,-well-drained-soil-on-terraces--and-smooth-plains-at have good survival-are-Rocky-Mountain juniper,-eastern- elevations of 4,550 to 5,150 feet. It formed in mixed allu- redcedar, ponderosa pine, Siberian elm, Russian-olive, and vium and eolian deposits. Included in mapping are small, hackberry. The shrubs best suited are skunkbush sumac, long and narrow areas of sand and gravel deposits and lilac, Siberian peashrub, and American plum. small areas of soils that are subject to occasional flooding. Wildlife is an important secondary use of this soil. The Some leveled areas are also included. cropland areas provide favorable habitat for ring-necked Typically the surface layer of this Nunn soil is grayish pheasant and mourning dove. Many nongame species can brown clay loam aobut 9 inches thick. The subsoil is light be attracted by establishing areas for nesting and es brownish gray clay loam about 14 inches thick. The upper cover. For pheasants, undisturbed nesting cover is es part of the substratum is light brownish gray clay loam. tial and should be included in plans for habitat develop- The lower part to a depth of 60 inches is brown sandy ment, especially in areas of intensive agriculture. Range- loam. land wildlife, for example, the pronghorn antelope, can be Permeability is moderately slow. Available water attracted by developing livestock watering facilities, capacity is high. The effective rooting depth is 60 inches managing livestock grazing, and reseeding where needed. or more. Surface runoff is medium, and the erosion This soil has fair to poor potential for urban develop- haz,rd is low. ment. It has moderate to high shrink swell, low strength, In irrigated areas this soil is suited to all crops com- and moderately slow permeability. These features create monly grown in the area, including corn, sugar beets, problems in dwelling and road construction. Those areas beans, alfalfa, small grain, potatoes, and onions. An exam- that have loam or sandy loam in the lower part of the pie of a suitable cropping system is 3 to 4 years of alfalfa substratum are suitable for septic tank absorption fields followed by corn, corn for silage, sugar beets, small grain, and foundations. Some areas of this soil are adjacent to or beans. Generally such characteristics as the high clay streams and are subject to occasional flooding. The poten- content or the rapidly permeable substratum slightly tial is fair for such recreational development as camp and restrict some crops. picnic areas and playgrounds. Capability subclass IIe ir- All methods of irrigation are suitable, but furrow ir- rigated, IIIc nonirrigated; Clayey Plains range site. rigation is the most common. Proper irrigation water 43—Nunn loamy sand, 0 to 1 percent slopes. This is a management is essential. Barnyard manure and commer- deep, well drained soil on terraces at elevations of 4,700 cial fertilizer are needed for top yields. to 4,900 feet. It formed in alluvium along Box Elder _ In nonirrigated areas most of the acreage is in small Creek. Included in mapping are small areas of soils that grain and it is summer fallowed in alternate years. have a loamy subsoil and small areas of soils that are sub- Winter wheat is the principal crop. The predicted average jest to rare flooding. yield is 33 bushels per acre. If the crop is winterkilled, Typically the surface layer of this Nunn soil is brown spring wheat can be seeded. Generally precipitation is too loamy sand overburden about 9 inches thick. The subsoil low for beneficial use of fertilizer. is dark to very dark grayish brown clay loam about 21 Stubble mulch farming, striperopping, and minimum til- inches thick. The substratum to a depth of 60 inches lage are needed to control soil blowing and water erosion. loamy very fine sand, loamy sand, or sand. . 132. SOIL SURVEY TABLE 14.--SOIL AND WATER FEATURES [Absence of an entry indicates the feature is not a concern. See text for descriptions of symbols and such terms as "rare," "brief," and "perched." The symbol < means less than; > means greater than] Flooding High water table Bedrock Soil name and Hydro-I , Potential map symbol logic: Frequency : Duration Months Depth Kind Months Depth Hard- frost -- group : - - ness action Ft In 1, 2 B :None : --- : --- >6.0 --- --- >60 --- :Moderate. Altvan : : 3*: , Aquolls D :Frequent----;Brief :Apr-Jun 0.5-1.0 Apparent Apr-Jun >60 --- High. 1 Aquepts D :Frequent----:Brief :Apr-Jun:0.5-1.0 Apparent Apr-Jun >60 --- High. 4*: : Aquolls D :Frequent----:Brief :Apr-Jun:0.5-1.5 Apparent Apr-Jun >60 --- High. Aquepts D Frequent----:Brief :Apr-Jun:0.5-1.5 Apparent Apr-Jun, >60 : --- :High. :I 5, 6, e None B 7, 8, 9 --- : --- : >6.0 --- --- : >60 : --- :Moderate. :. Ascalon : : : t, , 10 A Frequent---- Brief :Mar-Jun: >6.0 --- --- : >60 : --- Low. i Bankard 11 , 12 B None --- : --- : >6.0 --- --- I >60 --- :Moderate. Bresser : : 13 A None --- : --- >6.0 --- --- : >60 --- Low. Cascajo ii'? 14, 15, 16, 17---- B None - : --- >6.0 --- --- ; >60 : --- Low. Colby : : : 18*:Alli lby B None --- 1 --- >6.0 --- --- >60 I --- Low. '[j i i Illfena C None : --- 1 --- >6.0 --- --- >60 : -- Low. 19, 20 B Rare --- --- >6.0 --- --- >60 : --- ,Moderate. Colombo 21,j 22 C None --- I --- >6.0 --- --- >60 --- :Low. - Dacono B _. None a >60 ....- 23, 24 B None to rare --- : --- >6.0 --- --- >60 --- Low. Fort Collins I t 25, 26 B Rare to Brief May-Sep >6.0 --- --- : >60 : --- Low. Haverson common. 1 27, 28 ' C None --- --- >6.0 --- --- >60 : --- Low. Heldt 29, 30 A None --- --- >6.0 --- --- >60 : --- :Moderate. j. Julesburg 31 , 32, 33, 34---- B None --- --- >6.0 --- --- >60 : --- :Low. Kim : : 35*: : Loup D Rare to Brief Mar-Jun +.5-1.5 Apparent Nov-May >60 : --- :Moderate. common. Boel A Occasional Brief Mar-Jun 1.5-3.5 Apparent Nov-May >60 : --- :Moderate. 36*• Midway D :None --- --- >6.0 --- --- 10-20:Rip- :Low. : pable: See footnote at end of table. • k1: WELD COUNTY, COLORADO, SOUTHERN PART 133 TABLE 14.--SOIL AND WATER FEATURES--Continued : Flooding High water table I Bedrock I 1 name and :Hydro- Potential p symbol 1 logic Frequency Duration Months Depth Kind Months ;Depth Hard- frost :group ness action Ft •In i ,g le D None --- --- >6.0 I --- --- 10-20 Rip- Low. pable B None --- >6.0 --- --- 20-40 Rip- Low. 8 pable .on 40, 41 42, --- >60 .-- Moderate. 1 C None --- '-- >6.0 --- V In , 15, 46, 47, B ,None ' --- >6.0 --- --- >60 --- Low. llney A ;None --- --- >6.0 --- --- >60 --- Low. .od 51, 52, 53---- B ;None I --- --- >6.0 --- --- >60 --- Low. , •o 5 B ;None to rare --- --- >6.0 --- --- >60 --- Moderate. Soli 57 : C :None --- --- >6.0 --- --- 20-40 Rip- Low. >hill i pable , 59 : D :None --- --- >6.0 --- --- 10-20 Rip- Low. single pable ' i i '..ngle D ;None --- --- >6.0 --- --- 10-20 Rip- Low. pable : chill C :None --- --- >6.0 --- --- 20-40 Rip- Low. • pable D ,None --- >6.0 --- --- 10-20 Rip- Low. assel pable 53 .-- B None --- --- >6.0 --- --- 20-40 Rip- Low. b. ry pable 65 C None --- --- >6.0 --- --- 20-40 Rip- Low. 67 C None ___ --- >6.0 ___ ___ >60 --- Low. lm --- >6.0 --- --- >60 --- Low. A None --- is .urriorthents 70 A None --- >6.0 --- --- >60 --- Low. --- ent alent ent A :None --- --- >6.0 --- --- >60 --- Low. p D ;Rare to Brief Mar-Jun +.5-1.5 Apparent Nov-May >60 --- Moderate. : common. 73, 74, 75, " 6_ 77 B :None >6.0 - --- --- >60 --- Low. --- na See footnote at end of table. • cc CC APPROXIMATE SCALE 100000 co 1000 0 FEET I —I �ti I 1 el 6 $ • III NATIONAL F1000 INSURANCE PROGRAM hiii: °° FIRM FLOOD INSURANCE RATE MAP WELD COUNTY, 6 COLORADO �--- _ _- UNINCORPORATED AREA _ -_ I 13 PANEL 480 OF 1075 ' I IMEE MAP INDEX FOP PANELS NOT PRINTEOI V� I COMMUNITY.PANEL NUMBER 080266 0480 C • MAP REVISED: SEPTEMBER 28, 19821 I 24 - �._, federal emergency management agency J This Is an official copy of a portion of the above referenced flood map. It �/ was extracted using F-MIT On Line. This map does not reflect changes or amendments which may have been made subsequent to the date on the title block. 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Sheet No. of • Project: f \A dCtx.c C_\ -c-tom— Subject-q.v\-Cf.A\ Dp-A-a_ — per a•A-P Nr\cS Eje,J ccirlOvv = (3/4 n0 _C 3 O 'l_ K, = i,Ll Ka = 1.7 . )(3 -.... t-( )10p— 1 AV] a- D.g3`i {3.d, (3.tA \3,85 ' a .`by , _ �.� HT tU�ogt-et.ph�, • vctim •c•&,n » rwvn 1Sw:,(A �v, on. Lee vk LA.� t`_, -\IC 5. 11 )33 a. LQ1 1 .90 ','S7 PO-v- LI `71 Cc ,S1 4-1 .`l5 3,a`1 ;7, cbz2 LL) - vi (p , 2 ) 4,oc) 3, llL z. ze, I. �^, t pOi t: 12 (i \R2 = O.9835 = 20.418x-0.4981 c. 10 • y 12.952x-0.4981 I 2 = 0.9837 8 L \p1O771x ° 4976 R2 = 0.9836 a 6 cwa, k et fir' 0t}t a. 2 0 0 10 20 30 40 50 60 70 .9-year ■ 100-year 10-year TIME (min) DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF • I TABLE RO-5 Runoff Coefficients, C Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33. 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 _ 85% 0.66 0.68 0.71 0.75 0.77 0.79 • 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 Type B NRCS Hydrologic Soils Group 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 500/0 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 - 95% 0.79 0.81 0.83 0.85 0.87 0.88 • 100% 0.89 0.90 0.92 0.94 0.95 0.96 06/2001 RO-11 Urban Drainage and Flood Control District STEWART&LSSOCIATES 103 S. 482-9331 DRUM,FORT COLLINS, CO 80521 PH.Consulting Engineers and Surveyors By: (1).P(--) Date:7211(.2H Client: Gcti,1 `mqL Lr Sheet No. of Z Project: (Y-""c\�_�\<eL` �,�-c.�f� • Subject: 4',4,0c cJ tC2i V\u kC, CiCA J vv CAS Z / \wtee d'uouS Cl CS = U . ilo TIME, or C©tJGE:NT3t k ION i cam-\ L _ =moo' L5 7ILeD =-7 Cpu4w-e1 = C (I.1 --CS)r _ 0 ,3eis0.1 -p.14� 500 = c(i (Hon ‘so-s'3 DO`o.31 v = C4 s.S- -7CDo'3> o .4et cv15 lo= Lp O ,vI �D c ta0 D ,4.e1 . (o0 = zS. f n ,n • 41 .1 ZS, i = .(p rr.n IN T EwuS 1-71 Shoal hew -Th+ErrrVe5 1. I .w\.`\Ar Tom— Q, I ',V\\N- ,Were.V-L0\N 0.1Q (1 . 1)13.4 = Z.4 e �uro "CLwTlOOR. 6 . 1)1 Q. Y ) H,� CCS • • 103 S. UM, FORTSTEIJUARTgASSOC[ATES PH. 482-93318 FAX 482-938 LLINS, CO 80521 Consulting Engineers and Surveyors By: CY\ Date:-'J I Le 1 Client: ()curl Ma t Sheet No. of • Project: mac /, cit\I C\C -e J Subject: H1--nr',(. 71Cd rve `_LciL\C5 �Cc5 n 2 '/, A -Th pc_ C, = a .lp C Up' 0.S ` Acts E - DC/, 'L-TME OF (pNCENIMATIoN p} �1 L= 600 LL-3O L 0=1000 C,, =1 T = 6 3`) (..A • —O Av) 4`l —1 rm. O DC S = Cv5 = C.D0IL J= O . lcirIS jam= X4-1•-1 4"3t4 .O = � . cicf 1f 1 TEN ci) 56 GO ca1CS ELovJ 00 = 0,3 (o c-Cs Q„„)-- 051 ( I , (-O) = ?6!5 u� STEWART&ASSOCIATES 103 SS. MELDRUM F, F4ORT COLLINS, CO 80521 PH.Consulting Engineers and Surveyors v By: nTh n Date: J� l i> I Cars Client: C a '\ G 4�')a_c e Sheet No. ( of •Project: YY1 C tAt Subject: 1 4-nr„r_ (51N. 01: +t Act ut;vt. 4Y C 1Thir\cot CA. -Tit- -7d .3—} In Nr1 ELkSq, -'ri LYn atU e1o9ed I , C7 EDO -Rc st moo.,, DC- n\-ta PKr-DA.= x.12 1---3.C4 , loto CCs • V1 U5i ; • • CSTEWARTgASSOCIATES 103 S.PH. 82-933D1RF X 482-9382FORT 0LLINS, CO 80521 Consulting Engineers and Surveyors aBy: iinnrn Date: 31 \1 \ Client: Car.-i, tMgr 1 Sheet No. ) of Project: It r Y.e Lj C,I c r\P. Subject: l Ai'vrP\h, 'i;A n Ca\CS Mgt(v\ \ C A s ecc [' ."L 2c 2.i. mpert lcdz Sr 4" fry DiSt CIp `oz_p Thaw-) 2 o:.. flccc\ M \ I , n pc_ Z7 \\'11ecvcu J C p = c ,Z�r i I.; , �, /t(1 ._ -L Cttr\ A 1i rCic t Z, EJ A G O,D aW G C,�4y �:1_,' Odo2Ac CI0&Uced Gssc. <I efick • Seo sf L.04- Few Irn9erJic u% iica `- c,,qs Pc- C,;=OI2o G,,.,gOc5l a :O,-55 "EcS\n rez, nitet 8 A 1 mac-- coc ri 4 Ct,4\1 71 c, .si (Roo sc tack - La \ -L Z. JL .4cj kvtic sithOt35 ° `rftce.mm= O,LiC. A c.. ,- ilk:- -,I d CI,((a, f,...0;C, ,. i111 , 3ctS{\ C. P- _ 47,(06 - 1611Sc Cvt 1a ) &cc3 ec4Ur\ --- lit, LA ""Ca ,, •:fie, et Lt - -- v (1.5„0.1?) = a (�Z O Lo,Z7 �o -I-OW \v\t f000c et-ca ` o :::.2.:1 fvC... Lac = LI V illEcE din V P\jt. 1 BIZ. rA C- Z`/ I meNc ,J,005 r.'lL astc,,'ip c,,,,,, C),::_; \ C IU —s,Z(e I MACKEY CIRCLE Proposed Basins 3/112008 Basin Area CS CIO C100 Lo So euro To LI St Mfg Vt Tr To 15 lie inn) as Qio Ciao 1 OS 2.23 0.16 0.26 0.51 500 0.005_ 48.56 60 0.005 0.35 2.83 51.38 1.52 1.82 2.87 0.54 1.06 3.27 2 O5 11.17 0.16 0.26 0.51 500 0.005 48.56 885 0.005 0.35 41.72 90.27 1.15 1.38 2.17 2.05 3.99 12.35 A 3.15 0.3 0.38_ 0.57 500 0.0068 37.30 590 0.0068 1.24 7.95 45.25 1.62 1.94 3.06 1.53 2.32 5.49 B 8.47 0.18 0.28 0.52 500 0.0067 43.10 585 0.0067 0.57 17.02 60.12 1.40 1.68 2.65 2.14 3.99 11.69 C 6.6 0.18 0.27 0,52 500 0.0067 43.10 1075 0.0067 0.57 31.27 74.37 1.26 1.51 2.39 1.50 2.70 8.20 D 7.92 0.16 0.28 0.51 500 0.0057 48.48 820 0.0057 0.38 36.20 n 1 82.68 1.20 1.44 2.27 1.52 2.96 9.15 �' �2 Show No3rSaPe hbw Tnk05-1aes lA Cv VOALtt5 Wei( caleu ecl-ed . Ace. occ1Mn UJ2r\4_ usaci -0 LC) fcCO Drautiacy_ CcU*es ' ° �I D+TC�b • • • • • • STANDARD FORM9 MACKEY CIRCLE 10.Year Storm Calculated by am Dale 3/11/2006 Direct Runoff Total Runoff Street Pipe Size Travel Time Street DP Basin Area C CA To I (2 To I Sum CA D Slope Sleet Flow Design Flow Slope Pipe Size Lsngth Velocity TI Roulades (Acme) (Minutes) (InIHrl lots) (Minutest IwHrl Ices) IfaIl Me) lors) Ivfll (Inches) (Feel) (Opal (Minutest Total to DPI from Basin A 1 A 3.15 0.38 1.20 45.25 1.94 2.32 _ 0.005 2.32 275 1.08 4.32 To DP2 In await Total to DP2 from Basin B 0 8.47 0.28 237 80.12 1.65 3.99 Total to DP2 2 80.12 1.68 3.57 _6.01 0.005 6.01 360 ' 1.08 596 To DP4 Total to DP3 from Basin 1 CS 3 1 OS 2.23 0.26 0.58 51.38 1.82 1.06 _ 0.0058 1.08 1335 0.36 58.43 To DP4 Total to DP4 from Basin C C 86 027 1.76 74.37 1.51 2.70 / Total to DP4 4 j 109.81 1 1.25 5.93 7.40 , Released to DP6®6.66 c/a_ T,- .+ C Total to DPS from Bealn205 5 _203 11.17 0.28 2.90 90.27 1.JB 3.OB _ _ 0.005 3.99 1210 1.06 19.01 To DPB Total to DP6 from Basin 0 0 7.92 0.20 2.06 62.68 1.44 2.98 Total to DP6 tmm Basins D&2 O5 109.29 25 4.96 6.21. Total Flow at DPB 8 "12D] , / 9hOLO1 COLCs II STANDARD FORMS MACKEY CIRCLE 100-Year Storm Calculated by mm Date 3/11/2008 Olnot Runoff Total Runoff Sine) Plpe Size Travel Time Street OP Basin Area C CA To I 0 To I Sum CA 0 Slope Steel Flow Design Plow Slope Pipe Size Length Velocity Ti Remarks (Acne) (Minutes' PSW' (ors) (Minutes' IlmHr) (ors) (Wit) Icial (psi (fffftl (Inches' (Feet) (teal (Minutes' Total to DP1 from Basin A 1 A 3.15 0.57 1.80 45.25 3.08 5.49 0.005 5.49 275 1.06 4.32 To DP2 In swwale Total to DP2 Item Basin a B 8.47 0.52 4.40 80.12 2.55 11.69 Total to DP2 2 80.12 2.85 6.20 r 18.48• 0.0D5- 1640 • 360 1.06 5.89 To OP4 Total to DP3 from Basin I OS 3 1 OS 2.23 0.51 ' 1.14 51.38 2,87 3.27 0.0058 3.27 f 1335 0.38 56.43 To DP4 Total to Pdfrom Basin C C 8.8 0.52 3.49 7437 299 8.20• to DP 4 109.81, 1.97 10.77. 21.17 Released to DPB 06088 oft Total to DP5 from Basin OS 6 20S 11.17 0.51 5.70 909 2.17 12.35 \ _ 0,085 12.93 1210 1.011 19.01 To DPB Total to 0P8 from Sash D 0 7.92 0.51 4.04 82.68 227 9.15 _ Total to DP5 from Beelne D 5208. 109.29 l 1.97 874 19.19 Total Flow at OPB B (2`+ l� I\ 1 I7 lyi--..' /N ✓ S u MAJOR DETENTION VOLUME BY FAA&MODIFIED FAA METHOD (See USDCM Volume I Runoff Chapter for description of method) • Project Mackey Circle Basin ID: 1 (For catchments less than 160 acres only. For larger catchments,use hydrograph routing method) (Note:for catchments larger than 90 acres,CUHP hydrograph and routing are recommended) The user must fill in all of the blue cells for these sheets to function. Design Information(Input): _a'+ -.. -". .. " Catchment Drainage Imperviousness I,= f 9.34 percent , Catchment Dmhage Area A= 18.2200 acres Predevelopment NRCS Soil Group Type= C A,B,C.or 0 Return Period for Detention Control T= 100 years(2,5,10,25,50,or 100) Time of Concentration of Watershed Tc= 14_m'nutea— ` { Allowable Unit Release Rate(See Table A) q= { 0.17 cfslame t_J.. ;i T) L.„)-4) t) f?(s % r3 _ One-hour Precipitation P,= T.84 inches ..j¢' Design Rainfall mF Formula I=Cl'P11(C2NTc)"C3 "1 ) "C-t.) /'`. Coefficient One C,= 28.50 Coefficient Two C,= 10.00 Coefficient Three C,= 0.79 Determination of Average Outflow from the Basin(Calculated): Runoff Coefficient C= 0.53 "c Inflow Peak Runoff Op-in= 23.59 cis='r -- Allowable Peak Outflow Rate Op-out= 3.10 cis Ratio of Op-ouWp-in Rabo= 0.13 Determination of MAJOR Detention Volume Using FAA 8 Modified FAA Method 5 c-Enter Rainfall Duration Incremental Increase Value Here(e.g.5 for 5-Minutes) Rainfall Rainfall Inflow Average Outow Storage Adjustment Average Outflow Storage Duration Intensity Volume Outflow Volume Volume Factor Outflow Volume Volume minutes inches/hr cubic feet (FM,cfs) (FM,Cr) (FM,cf) (Mottled) (Mod.cfs) (Mod,of) (Mod.of) (input) (output) (output) (output) iottpul) (output) (output) (output) IOutpul) (output( 5 9.53 27,606 2.17 650 28,955 180 3.10 929 26,676 10 7.59 43,987 2.17 1,301 42,666 180 3.10 1,858 42,129 • 15 6.36 55,317 2.17 1 951 53,365 1.00 3.10 2,786 52,529 20 5.51 63,662 2.17 2,602 61,260 1.00 3.10 3,]17 60,145 25 4.88 ]0,8]5 2.17 3,252 6],423 1.00 3.10 4,646 68,029 30 4.39 76,319 2.17 3,903 72,416 1.00 3.10 5,575 70,744 35 4.00 81,128 2.17 4,553 76,574 1.00 3.10 6,505 74,623 40 3.68 85312 2.17 5,204 60,109 1.00 3.10 7,434 77,679 45 3.41 89.015 2.17 5,854 83,161 1.00 3.10 8,383 60,652 50 3.19 92,336 2.17 6,505 85,831 1.00 3.10 9,292 63,043 55 2.99 95,345 2.17 7,155 86,190 1.00 3.10 10,221 85,124 60 2.82 98,099 2.17 7,805 90,293 1.00 3.10 11,151 88,948 65 2.67 100,636 2.17 8,456 92,180 1.00 3,10 12,080 88,556 70 2.54 102,990 2.17 9,106 93,864 1.00 3,10 13,009 89,981 75 2.42 105.186 2.17 9,757 95,429 0.99 3.06 13,545 91,341 80 2.31 107,245 2.17 10,407 96,838 0.96 2.98 14,310 92,935 85 , 2.22 109,183 2.17 11,058 98,126 0.94 2,90 14,775 94,409 90 2.13 111,015 2.17 11,708 99,307 0.91 2.82 15,239 95,776 95 2.05 112,752 2.17 12,359 100,393 0.89 276 15,]04 97,048 100 1.97 114,403 2.17 13,009 101,394 0.87 2.69 16,168 98,235 105 1.91 115,978 2.17 13,680 102,319 0.85 2.64 16,633 99,345 110 184 117,484 2.17 14,310 103,174 0.84 2.59 1?098 100,386 115 1.78 118,926 2.17 14,960 103,966 0.82 2.55 17,582 101,364 120 1.73 120,311 2.17 15,811 104,700 0.81 2.50 16027 102,284 125 1.68 121,642 2.17 16.261 105381 0.80 2.4] 10,491 103,151 130 1.63 122.925 2.17 16,912 106,013 0.78 2.43 18,956 103,969 135 1.59 124,183 2.17 17,562 106,601 0.77 2.40 19,421 104,742 140 1.55 125,359 2.17 18,213 107,146 0.76 2.37 19,865 105,473 145 1.51 128,516 2.17 18,863 107,653 078 2.34 20,350 106,166 150 1.47 127,637 2.17 19,514 100,123 0.75 2.31 20,815 106,822 155 1.43 128,724 2.17 20,164 108,559 0.74 2.29 21.279 107,444 160 1.40 129,779 2.17 20,815 108,964 0.73 2.26 21,744 106,035 165 1.37 130,604 2.17 21465 109,339 0.72 2.24 22,208 108,598 170 1.34 131,802 2.17 22,115 109,687 0.72 2.22 22,673 109,129 175 1.31 132,773 2.17 22,766 110,008 0,71 2.20 23,136 109,638 180 1.28 133,720 2.17 23,416 110,303 0.71 2.19 23.602 110,118 185 1.26 134,643 2.17 24,067 110.576 0_70 2.17 24,067 110,576 97' :'p a, FAA Major Storage Volume(cubic R)= 110,576 Mod.FAA Major Storage Volume(cubic ft.l= 110,576 .. 1t, ""'1 FM Major Storage Volume(acre-R)= 26355 _...-Mod.FM Major Storage Volume(acre-ftie 2.6385 • UDFCD DETENTION VOLUME ESTIMATING WORKSOO `rsliC- ioonr 2.01,Released August 2006 1-1:•;- ,.-- -('•' UO-Detenfonxls,Modified FM 3/112009,7:53 AM Design Procedure Form: Extended Detention Basin (EDB) -Sedimentation Facility Sheet 1 of 3 Designer: Mary Mateo Company: Stewart&Associates • Date: March 11,2008 Project: Mackey Circle Location: Weld County,CO 1. Basin Storage Volume I.= 9.34 A)Tributary Area's Imperviousness Ratio(i=I,/100) i= 0.09 B) Contributing Watershed Area(Area) Area= 18.220 acres C) Water Quality Capture Volume(WQCV) WQCV= 0.06 watershed inches (WQCV=1.0'(0.91'1 -1.19'1+0.78*I)) D) Design Volume:Vol=(WQCV/12)*Area 1.2 Vol= 0.1152 acre-feet 2. Outlet Works A) Outlet Type(Check One) X Orifice Plate Perforated Riser Pipe Other. • B) Depth at Outlet Above Lowest Perforation(H) H= 0.70 feet C) Recommended Maximum Outlet Area per Row,(A0) A0= 1.6 square inches D) Perforation Dimensions: i) Circular Perforation Diameter or D= 1.375 inches H)Width of 2"High Rectangular Perforations W= inches • E) Number of Columns(nc,See Table 6a-1 For Maximum) nc= 1 number F) Actual Design Outlet Area per Row(Ao) A0= 1.5 square inches G) Number of Rows(nr) nr= 2 number H) Total Outlet Area(As) = 3.1 square inches 3. Trash Rack A) Needed Open Area:A,=0.5*(Figure 7 Value)'Ao, h= 101 square inches B) Type of Outlet Opening(Check One) X <2"Diameter Round 2"High Rectangular Other. C) For 2",or Smaller,Round Opening(Ref.: Figure 6a): i) Width of Trash Rack and Concrete Opening(W0o00) from Table 6a-1 = 6 inches ii) Height of Trash Rack Screen(H7p) HTR= 38 inches • UD-BMP-EDB.xls,EDB 3/11/2008, 12:11 PM • • • Mackey Circle Pond Volume Elevation Area (SF) Volume(CF) Cummulative Volume(CF) 47.5 0 48 5316 1329 1329 49 39300 22308 23637 50 95190 67245 90882 51 , 150024 122607 213489 Toal Volume (Ac-Ft) 4.90 O u3O Cif = Di 1 ) 52_ , � � 11,0 `-l tit O ciL ,lc c-c-j STEwART$,ASSOCIATES 103 PH. SS..MELDRF MELDRUM, 482-9FORT COLLINS, CO 80521 Consulting Engineers and Surveyors By: 1\f'(1''1 Date:31 II I Client: (9&r ) i PLr .- i Sheet No. of i • Project: ff f G f, t ft,r, L _ Subject: r r st _ { f F .� '�C_ � �� .� -d- p; k 1cw ('A i C CR tr. x. 1=1 !4 i O tt 0 .55 (0 .Q41 - = I3, 2 • !1_- CcJt) ,,70 I't c s I .1 t ? , 28 — '\' ` c( )r`= �). .:' 32. z (, ) ' = �k • 1- a Circular Pipe Flow Project: Mackey Circle • Pipe ID: Pond Outlet Pipe Tc r w rrJ e - 'How angle V )3 Design Information(Input' Pipe Invert Slope So= 0.0050 ft/ft Pipe Manning's n-value n= 0.0130 Pipe Diameter D= 18.00 inches Design discharge Q= 6.6 cfs Full-flow Capacity(Calculated' Full-flow area Af= 1.77 sq ft Full-flow wetted perimeter Pf= 4.71 ft Half Central Angle Theta= 3.14 rad Full-flow capacity Qf= 7.5 cfs • Calculation of Normal Flow Condition Half Central Angle(0<Theta<3.14) Theta= 2.05 rad Flow area An= 1.39 sq ft Top width Tn= 1.33 ft Wetted perimeter Pn= 3.08 ft Flow depth Yn= 1.10 ft Flow velocity Vn= 4.76 fps Discharge Qn= 6.6 cfs Normal Depth Froude Number Fr„= 0.82 Calculation of Critical Flow Condition Half Central Angle(0<Theta-c<3.14) Theta-c= 1.90 rad Critical flow area Ac= 1.24 sq ft Critical top width Tc= 1.42 ft Critical flow depth Yc= 0.99 ft Critical flow velocity Vc= 5.31 fps Critical Depth Froude Number Frc= 1.00 • UD-Culvert-Pond Outlet.xls, Pipe 3/12/2008, 11:28 AM ST EWARTgASSOCIATES 103 S PH 82 9 3DIRFAX 482-93COLLINS, CO 80521 82 Consulting Engineers and Suryeyors r ? By: in nr Date:7,1171 Zg Client: ti,+""'-,t yl f�aLs >:. , ? Sheet No. of • Project: �'�i`lu 0ct'�.� C � •r C�.C� Subject; `1 i.tom \1 J••: p S-r �Y t Z i ?e - C..t� _a-et It/ - ; ) J Q jc -7, L/ �e ;Li '� ;1�G.U t7 � L i • • Normal Flow Analysis - Trapezoidal Channel • Project: Mackey Circle Channel ID: Roadside n F A e � / Yo 1 Y I 1 • Z1 c ]3 E2 Design Information(Input) Channel Invert Slope So= 0.0050 ft/ft Manning's n n= 0.035 Bottom Width B= 0.00 ft Left Side Slope Z1 = 3.00 ft/ft Right Side Slope Z2= 4.00 ft/ft Freeboard Height F= 0.00 ft Design Water Depth Y= 1.00 ft Normal Flow Condtion(Calculated) Discharge Q= 6.46 cfs Froude Number Fr= 0.46 • Flow Velocity V= 1.85 fps Flow Area A= 3.50 sq ft Top Width T= 7.00 ft Wetted Perimeter P= 7.29 ft Hydraulic Radius R= 0.48 ft Hydraulic Depth D= 0.50 ft Specific Energy Es= 1.05 ft Centroid of Flow Area Yo= 0.33 ft Specific Force Fs= 0.10 kip • UD-Channels Roadside.xls, Basics 3/11/2008, 1:05 PM Normal Flow Analysis - Trapezoidal Channel Project: Mackey Circle • Channel ID: A - Culdesac to Pond :H, Yo / 1 atYY Z1 E > Z2 Design Information(Input) Channel Invert Slope So= 0.0050 ft/ft Manning's n n= 0.035 Bottom Width B= 0.00 ft Left Side Slope 21 = 10.00 ft/ft Right Side Slope Z2= 20.00 ft/ft Freeboard Height F= 0.45 ft Design Water Depth Y= 0.55 ft Normal Flow Condtion (Calculated) Discharge Q= 5.77 cfs Froude Number Fr= 0.43 Flow Velocity V= 1.27 fps • Flow Area A= 4.54 sq ft Top Width T= 16.50 ft Wetted Perimeter P= 16.54 ft Hydraulic Radius R= 0.27 ft Hydraulic Depth D= 0.28 ft Specific Energy Es= 0.58 ft Centroid of Flow Area Yo= 0.18 ft Specific Force Fs= 0.07 kip • UD-Channels Culdesac to Pond.xls, Basics 3/11/2008, 2:38 PM Normal Flow Analysis - Trapezoidal Channel • Project: Mackey Circle Channel ID: 15 - Channel from north just prior to pond outlet F c T 7 Yo 1 Y 1 Z1 .c > Z2 Design Information (Input) Channel Invert Slope So= 0.0050 ft/ft Manning's n n= 0.035 Bottom Width B= 0.00 ft Left Side Slope Z1 = 18.50 ft/ft Right Side Slope Z2= 18.50 ft/ft Freeboard Height F= 0.00 ft Design Water Depth Y= 0.70 ft Normal Flow Condtion (Calculated) Discharge Q= 13.54 cfs Froude Number Fr= 0.44 • Flow Velocity V= 1.49 fps Flow Area A= 9.07 sq ft Top Width T= 25.90 ft Wetted Perimeter P= 25.94 ft Hydraulic Radius R= 0.35 ft Hydraulic Depth D= 0.35 ft Specific Energy Es= 0.73 ft Centroid of Flow Area Yo= 0.23 ft Specific Force Fs= 0.17 kip • UD-Channels north pre outlet.xls, Basics 3/11/2008, 2:38 PM Normal Flow Analysis - Trapezoidal Channel Project: Mackey Circle • Channel ID: Basins D and 2OS to Pond (nSr(kl� ) F c Y 1L • TY° 1 Z1 E Z2 • Design Information (Input) Channel Invert Slope So= 0.0050 ft/ft Manning's n n= 0.035 Bottom Width B= 0.00 ft Left Side Slope Z1 = 30.00 ft/ft Right Side Slope Z2= 30.00 ft/ft Freeboard Height F= 0.00 ft Design Water Depth Y= 0.50 ft Normal Flow Condtion (Calculated) Discharge Q= 8.96 cfs Froude Number Fr= 0.42 Flow Velocity V= 1.19 fps • Flow Area A= 7.50 sq ft Top Width T= 30.00 ft Wetted Perimeter P= 30.02 ft Hydraulic Radius R= 0.25 ft Hydraulic Depth D= 0.25 ft Specific Energy Es= 0.52 ft Centroid of Flow Area Yo= 0.17 ft Specific Force Fs= 0.10 kip • UD-Channels D and 2OS to Pond.xls, Basics 3/11/2008, 2:41 PM Normal Flow Analysis - Trapezoidal Channel • Project: Mackey Circle Channel ID: C — Channel to East F X ` T Y° 1 Y 11 \ • Z1 c a Z2 Design Information(Input) Channel Invert Slope So= 0.0057 ft/ft Manning's n n = 0.035 Bottom Width B= 0.00 ft Left Side Slope Z1 = 4.00 ft/ft Right Side Slope Z2= 4.00 ft/ft Freeboard Height F = 0.00 ft Design Water Depth Y= 1.26 ft Normal Flow Condtion (Calculated' Discharge Q= 14.70 cfs Froude Number Fr= 0.51 • Flow Velocity V= 2.31 fps Flow Area A= 6.35 sq ft Top Width T= 10.08 ft Wetted Perimeter P= 10.39 ft Hydraulic Radius R= 0.61 ft Hydraulic Depth D = 0.63 ft Specific Energy Es = 1.34 ft Centroid of Flow Area Yo= 0.42 ft Specific Force Fs= 0.23 kip UD-Channels East.xls, Basics 3/11/2008, 2:39 PM Normal Flow Analysis - Trapezoidal Channel Project: Mackey Circle • Channel ID: 1)— Basins C and 1OS to Pond F n Vic Y° Z1 Y 1� • v e H 3 Zz Design Information (Input) Channel Invert Slope So= 0.0050 ft/ft Manning's n n= 0.035 Bottom Width B= 0.00 ft _ Left Side Slope Z1 = 12.00 ft/ft Right Side Slope Z2= 12.00 ft/ft Freeboard Height F= 0.00 ft Design Water Depth Y= 0.50 ft Normal Flow Condtion(Calculated) Discharge Q= 3.58 cfs Froude Number Fr= 0.42 Flow Velocity V= 1.19 fps Flow Area A= 3.00 sq ft • Top Width T= 12.00 ft Wetted Perimeter P= 12.04 ft Hydraulic Radius R= 0.25 ft Hydraulic Depth D= 0.25 ft Specific Energy Es= 0.52 ft Centroid of Flow Area Yo= 0.17 ft Specific Force Fs= 0.04 kip • UD-Channels C and 1OS to Pond.xls, Basics 3/11/2008, 2:40 PM Hello