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Home My WebLink About20003084.tiff 05/02/98 11:49 03 484 0454 EMPIRE LABS. ®004 April 7, 1993 Coulson Excavating 3609 North County Road 13 Loveland, Colorado 80537 Attention: Mr. Dick Coulson Gentlemen: • We are pleased to submit our Report of a Mineral Evaluation prepared for the 40-acre traot of land located at County Road 54 approximately three miles north-northwest of Johnstown, Colorado. The accompanying report presents our �g in the subsurface. Very truly yours, d`Q,Q..•a•�"••.;•ny, ENTIRE LABORATORIES, INC. /coif .4o•••., ( -11 --� 6 i-d1 23702 ofel: /tiff g isa R. Schoenfeld, P. %ry�ryd'S,�..A`�e��o��a Geotechnical Engineer u,,,,1immw0N Reviewed� _ r�by: A // litWKIMmo CD C. Smith, P.E. '/°ft4k.- Chester CC" Division Manager J3 2000-3084 ii • • 05,02 98 11 : 19 feTh 484 0454 EXPIRE LABS. ®005 REPORT! OF A MINERAL EVALUATION SCOPE This report presents the results of a mineral evaluation prepared for the Phases I and III of the Challenger Pit at County Road 54 west of county Road 15h in Weld County, Colorado. The evaluation included drilling six (6) test borings. The objective of this evaluation was to determine the depths and volumes of the overburden and sand and gravel strata encountered at the site. SITE EXPLORATION The field exploration, carried out on March 26,E 1993 , consisted of drilling logging and sampling six (6) test borings . The number and location of the test borings was determined by Mr. Dick Coulson. The approximate locations of the test borings are shown on the Test Boring Location Plan included in Appendix A of this report. Boring logs prepared from the field logs are shown in Appendix A. These logs show soils encountered, location of sampling and groundwater at the time of the investigation. The borings were advanced with a 4-inch diameter, continuous-type, power-flight auger drill. During the drilling operations, a geotechnical engineer from Empire Laboratories, Inc. was present and made continuous observations of the soils encountered. SITE LOCATION AND DESCRIPTION The site is located on the south side of Colorado Highway 402 approximately 31 miles east of 1-25 in weld county, Colorado. More -1- .v v_ __. .... �„w ... v�v• ..JSA .NL L1uO.,11 yy..ov • particularly, the site is described as a tract of land situate in the Northwest 1/4 Hof Section 29 and the Northeast 1/4 of the Southwest 1/4 of Section 29, Township 5 North, Range 67 west of the sixth P.M. , Weld County, Colorado. The area under investigation is the northwest portion of the existing Challenger Pit run by Western Mobile, Inc. The north and east portions Of the site (Phase III) -consist of farmland. The west portion of the site (north end of Phase I) consists of swamp land. The south portion of the site (south portion of Phase I) was under gravel mining operations at the time of our investigation. The site is bordered by Colorado Highway 402 (Weld County Road 54) to the north, the Hill and Brush Ditch to the northeast, the Great Western Railroad to the east, the Big Thompson River to the south and farmland to the west. SOIL AND GROUNDWATER CONDITIONS The following describes the characteristics of the primary soil strata encountered at the site in order of increasing depths along with current groundwater conditions. (1) ToDsoiI: A one-half (1/2) foot layer of silty topsoil was encountered at the surface of Borings 1 and 5. The topsoil has been penetrated by root growth and organic matter. (2) fill Material: A four-foot layer of fill material was encountered at the surface of Boring 6. The fill material consists of silty sand and gravel. I i (3) Lean Clay with Sand; The clay layer was encbuntered at the surface of Borings 2, 3 and 4 and below the topsoil in Boring 4 and extends to depths of four and one-half -2- 05/02"96 11:55 $3r484 0454 EMPIRE LABS. '/^•\ V)'HI LOG OF BORING NO. 2 Page 1 of 1 cUENT I ARCNITBCITTENGINEETI Coulson Exavating SITE liwy. 402(County Rd. 54) PROTECT Weld County, Colorado Gravel Excavating ____ -- SAMPLES TESTS ._ ____ t7 s r pp _I 0 Li_ H W o DESCRIPTION cc z` cc z I--n- I-. to w -i ,n D ID flty1 d Lam,) a u8, ro t1 re Q Ls. w ul E Y W VC J o K 21-to - La Approx. Surfer Elev.: ft. w D z t- a taro t ao- Mtntl - PA V. TITAN CLAY WITH SAND - /'/ Brown.dry towel, medium stiff 1 SS 12', 5 S , PA Za5 $ - 6 9 2 SS 12 ,II TY SAND 10 _ PA r."3/412.0 Tan/gray. wet, loose —� 3 33 l2" 27 SIT TY SAND GRAVEL 15 _ PA AND COBBLES i � Tan/gray, wet — T..._ Medium dense to very dense = - 4 SS 12" 33 r .� 20 - PA ;s — - s ss 7=50/7" 25 4. - PA �:' 26.0. WGATHERE11 sI TgrOt$ _ 28.0 Gny. moil, bard — 29.1 STL - \Gray, dry 6 S3 I'very Lard / i0/1' END OF BORING THE STRATIPICATION LIMES REPRESENT TIE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AD ROCK TYPES! IN-SITU, THE Twist TIOI MAY BE GRADUAL. WATER LEVEL OBSERVATIONS A-5 BORING STARTED 3-2,6-93 ._ WI. $ s'-s" I w.D. = Empire Laboratories BORING COMPLETED 3-26-93 Ix". z Incorporated RI9 CMF-S5 FoR 4AN DAR Division of Tc moon APPROVED (1R$ R. 20935052 WL Holes.filled in A.B. i t e5. 02. 96 11:55 aJefie\ .Isa 0454 EMPIRE LABS. '^ IQu15 LOG OF BORING NO. 3 Page 1 of 1 CLIENT I ARCHITECT/ENGINEER Coulson Excavating 1 sire ! Hwy. 402 (County Rd. 54) ra^'P`T Weld County. Colorado Gravel Excavating SAMPLES TESTS J \ } -1 ILL L } W W y Z2 DESCRIPTION a= W pa w ?y F w LLHt`u) W N m 8 dJ H }LL 0 Approx. Surface Elee.: ft. o r- mm 2 8R sum. — PA L FAN CLAY WITH SAND jBrown, dry to wet, medium stiff - 1 SS 12" 5 5 - PA - j R 4 10.0 IO - 2. SS. 12' 5 - PA SR.TY SAND - f' SR wet, Imes - 13.0 rv,.:., - - 3 SS 12' 17 + IS - PA - SILTY SAND. Q]tAYRL - ,AND COBBLES — Tao/gray,wet - >` Medium dense to dense - 4 SS 12' 33 20- PA T7~ f 5 SS 12" '38 y 25 _ PA 4'' 27.0 - 28.0 WEATHERED SIT TSTONE — \dray,mad,bard I - -n.e 29.3 SIL / SS' 3' 50/3' IOray, dry,vary bard END OP BORING fr TN! STRATIFICATION LIMES R@RECERT THE APPROXIMATE EOIA*ART LIMES rs OMEN L AS ROCIC T Irmo, THE TMssITIat.MAY KMO ELNL. w* aWill.Dal T Amo A-6 DORM STARTED 3-24-93 wC--4 8,-2a w.D. = Empire Laboratories BORINGcottn.nD 3-26-93 wt. incorporated , RIG CME-55 NVREMAN DAM 1 DIvi.Inn of T.rr.<on APPROVED Nits Juts* 20935052 ��'I- Holes filled In A.B. 05.02.86 11:56 6/"'` 484 0454 EMPIRE LABS. Jr', 'Qjulu • LOG OF BORING NO. 4 Page lofl CLIENT I ARCRTTE T/WNCBIEER Coulson Excavating I SITE Hwy.402 (County Rd. 54) PROTECT Weld County, Colorado 1 _ GTa►el Excavating SAMPLES TESTS _ QQ,+I • v r 0 H DESCRIPTION N; w z� H� CC CC CC oa. S i g mm 2 SaCl 1l��iia 0 Approx. Surface Elev.: fl.X w a l// - 1 PA LPAN CT AY WITH SAND Brown, moist, medium stiff 4.5 — g 1 SS 12' 5 Sn.TYSAAD_ 5 - PA Tan/Tod/gray, wet, loose = 8.0 -_ y.= - 10 2 SS 12' 13 - PA Sn T1'SAND. GRAYBT. _ AND CORRLPS 'y Tsn/red/gray, wet — 3 SS 12' 15 Medium dense to dense 15 _ PA - 4 SS 12' 49 20 - PA _. a' 23. :..gc 24.0 WEATHERED,Sn.T.STONB I - 5 SS 6' 90/6' .. 243 ray, moist.hard / ray, dry, very hard END OF BORING i i s i TN! STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES flu ROIL AND ROI= IN-SITU, TEE TRANSITION MAY BE ORADUAL• F'"' WATER traitO Atn.s A-7 Nonwo STARTED 3-24-93 WI. $ 4,4. w.D. = Empire Laboratories SOUND COMPLETED 3-26-93 WL i Incorporated , RIO Cfne-S5 FOREMAN DAR WL , Divirioo ofTemeoa APPROVED NRS JOB I 20935052 Holes relied in A.B. u5:wi B6 11:57 $3 ' 484 04.54 EXPIRE LABS. !M cl.IU17 '-, LOG OF BORING NO. 5 _ Page 1 or 1 CLIENT I ARCIUTECT/ENCDJEER I Coulson Excavating ' snx ; Hwy. 402(County Rd. 54) PROJECT I Weld County, Colorado Gravel Excavating SAMPLES TESTS ED J N r M DESCRIPTION tn c w z• 2 H x x p. M- o k3� ii a _ ~ 4 U /-3 cH TLL KLL L.-^ Approx. SurfaceElev.: fL wo �- ys 2 oa aria �"'�• 0.5 6• TOPSOIL. — PA Ai< LRAN CTAY WITH SAND — Brown. moist to wet Stiff to very stiff - 1 SS 12' 17 �/! 5 PA �• v - 2 ss 12' 8 ,FG•H 11.0 10 - PA SILTY SAND - Tan/gray/red,wet, loose _ 14.5 3 SS 12" 14 IS - PA Sun SAND.GRAVEL. - AND CORBT.BS - Tan/gray/red, wet - • _ Medium dame to dense 4 SS 12' 36 � — 20 - PA : _ ••..'. + 23.0 - WPATERRED SEti= .TSTONE - 24 .Glny,dry1 bard r---- .r---- . noir $ 5 ss RTT.TRTANR Gray,dry, very hard END OF BORING + I 1 ' i TAR STRATIFICATION LINES MDMUNT THE APPROXIMATE BODmCM1 LINES r ill E7It� L Atb alai I III-SITU, THE TMHSITIOH NAT DE GRADUAL. WA LEVEL. A_8 BORING S'1'ARTBD 3-26-93 WL $ g•-s- W.D. Empire Laboratories BOI1N0 COMPLRTRD 3-26-93 wL I Incorporated RIG CME-55 _ FOREMAN DAR` ' Divbiw of Temcon Holes filled w A.B. APPROVED NRS /Oar F 20935052 4 ub'uZ:atl 11:4, •(p1 - 4414 0444 Lariat LABS. """N %Jul* LOG OF BORING NO. 6 Page 1 of 1 _ CLIENT i ARCIOTECTIINCR Coulson Excavating I. SITE Hwy. 482 (County Rd. 54) PROJECT Weld County, Colorado Gravel SAMPLES Excavating— TESTS .4 Id .. _J r• N >- • es LL H4Ox-J EILI CO DESCRIPTION '- in m Cr zN P- g�pc ag d d s f•o H ru. 5�FN: Z.3 Approx. Surface E1er.: ft. o it Nm 2 we. 3Na ••%% PILL-Silty-SDty sal with gravel _ PA •• •••e _ �•• _ - •••• 4.0 _ 1 3S 12' 8 4Ti TY SAND 5 _ PA S ti :•.; Tanhed/otaoge, mist,. loose - — g.0 —. :s f;,•;r - 2 SS 12' 12 .,I•:4 10 _ PA F':• STLTY SAND GRAVEL - Es' AED COABT.SS t}ray/taOlotange.wet - 4::... • Medium dense to very dense - > 3 SS 12' 40 15 re•:.7 - PA ../ - J.:,.a _ :1'?/' - 4 33 6' 50/6' yT 20 _' PA - .'.•, . 22.0 - t 2,3.D 2atin tRRD an_TS•I.ONT? - - — `Dray,dry,hard r- 24.5 .iaia,nR I J 5 SS 0. 50/0" foray, dry;very hard BND OP BORING i 1 •i 1 i TN[ STRATIFICATION LINOS O P*E ERT TIN! APPROXIMATE COCIOART LIMNS tr• OOT'1 ASSITY, INC TMs�1T MAY sR Nr�owt• soNE4O START'® 3-2E-93 wL U None WI,. * Empire Laboratories HOMO COMPLETED 3-26-93 WI. Incorporated RIO ovie-ss FOREMAN DAR _ ' DivWea o(Tert*eon APPROVED NRS - ,00 e 20935052 w t Holes filled fa A.B. efi.VJ• V4 ISO ll. •0 I U4.0.1 car 1N6 LSDD. . %WU, r (4-1/2) to eleven (11) feet blow the surface. The lean clay isl moderately plastic and medium stiff to vary stiff, contains relatively minor amounts of sand and traces of gravel and is dry to wet with depth. (4) Silty Sand: A two and one-half (2-1/2) to four and- one- half (4-1/2) foot layer of silty sand was encountered below the topsoil, fill and clay layers and extends to depths of five (5) to fourteen and one-half (14-1/2) feet below the surface. The silty sand is generally fine, loose and moist to saturated. (5) Silty Sand. Gravel and Cobbles: An eight and one-half (8-1/2) to seventeen and one-half (17-1/2) foot layer of silty sand, gravel and cobbles was encountered below the silty sand layer in all six borings and extends to depths of twenty-two (22) to twenty-seven (27) feet below the r surface. The sand, gravel and cobbles is well graded and medium dense to very dense, contains minor to moderate amounts of silt and is saturated in situ. It is estimated that the maximum size of the cobbles encountered is eight (8) inches in diameter. (6) siltstone Bedrock: The bedrock was encountered below the sand and gravel layer and extends to the depths explored. , The upper one (1) to two (2) feettpof the bedrock is highly weathered; however, the underlying siltstone is firm. (7) Groundwater: Free groundwater was encountered in Borings 1 through 6 at depths of three (3) to eight and one-=half (8-1/2) feet below the surface at the time of the investigation. Water levels in this area are subject to 'a.' —3— 05'U2;96 11:51 a� 484 0454 EMPIRE LABS. ^ ®008 change due t+ seasonal variations and fluctuationslin the flow of the Hill and Brush Ditch northeast of the site and the Big Thompson River south of the site. RECOMMENDATIONS AND DISCUSSION It is our understanding the area under investigation is to be used as a gravel pit. We further understand that a strip of land approximately 60 to 200 feet wide running generally northwest to southeast between Phases I and III of the project is be left unmined. Based on the test borings drilled at the site, it is our opinion the sand, gravel and cobble layer encountered at the site is suitable for mining for use as construction materials. The overburden thickness encountered in our test borings (including the silty sand stratum) ranges from five (5) to fourteen and one-half (14-1/2) feet. The underlying sand, gravel and cobble stratum encountered in our test borings ranges from eight aqd one- half (8-1/2) to seventeen and one-half (17-1/2) feet thick. Based on these thicknesses and approximate areas (excluding the aforementioned strip to be left unmined) approximately 650,000 cubic yards of overburden will have to be removed to obtain approximately 1, 120, 000 cubic yards of sand, gravel and cobbles. Hence, the ratio of sand, gravel and cobbles volume to overburden volume is approximately 1 . 7. The gravel encountered appears to be of good quality and contains durable rock fragments composed of igneous and metamorphic bedrock fragments. The above quantities are based on the thicknesses of the overburden and sand, gravel and cobble strata encountered in the test borings and. the approximate area suitable for extraction. Safe distances should be kept from property lines, roads, railroads and waterways. Since the sand, gravel and cobble stratum was encountered below groundwater, temporary dewatering of the pit or use of a drag line will be required to remove the sand, gravel and 1 -4- VJ• UL- WU 11:0L •U•.✓'. 404 WDJ tnrimt LABS. Al 1®009 • cobbles} Excavation and dewatering of thel pit should be done carefully to protect the adjacent property, toads, railroads and waterways. GENERAL COMMENTS Variations in overburden and sand, gravel and cobble thicknesses, the quality of the sand, gravel; and cobbles and soil and groundwater conditions may exist between test borings. These variations may not become evident until quarrying operations take place. 'It should be noted the quantities presented in this report are based on thicknesses of overburden and sand, gravel and cobbles encountered in the test borings drilled at the site. Additional test borings, test pits and laboratory analyses may be needed prior to proposed quarrying operations to more accurately evaluate the quantity and quality of the granular materials encountered at the .•- sits. :1 d -5- 00/02+U8 11:53 U3' 484 0454 EMPIRE LABS. ' ®010 I I e.:, 1"" 05/02/96 11:53 1730r\464 v.15-1 tMr1Kt LWb. /y, VY•.,♦ I • I^ TEST BORING LOCATION PLAN I \ I I i l%i � eD it_ r5 � J ) IS r -.N� Ph- -, z \N-N\---s\ . 1 Lj . 4/0 , a. s V4 i oN �'+IIl i Pt &OA,�.�i ". _11 inn �,.u�., I s o p FM APIRF L IRATORIES. INC. - yy , _. vu •� /Y 'sr.' ''JY IY IY LM lAL 41GJ. ^ %JUli . GENERAL NOTES DRILLING & SAMPLING SYMBOLS: $5 . Spilt Spoon - 114" I.O., 2- O.0., unless otherwise noted PS . Piston Sample , ST : Thin-Walled Tube r Cu.,. Unless otherwise noted WS : Wash Sample ' PA : Power Auger , FT Fish Tail;Bil HA : Hand Auger RB : Rock Bit' DB : Diamond Bit - 4", N. R BS : Bulk Sample AS : Auger Sample PM Pressuremeter HS : Hollow Stem Auger DC : Dutch Cone WB Wash Bore Standard "N" Penetration:, Blows per fuel Of a 140 pound hammer falling 30 inches on;a 2 inch OD split spoon, except-where noted. . WATER LEVEL MEASUREMENT SYMBOLS: WL Water Level WS . While Sampling WCI : Wet Cave In WO While Drilling DOI . Dry Cave in BCR : Before Casing Removal AB After Boring ACR : Atter Casing Removal Water levels indicated on the boring lugs'ere the levels measured in the borings at the limes indicated. In pervious soils, the indicated levels mey reflect the location of groundwater. In low permeability soils, the acnuratn rioter. .minati:n of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soli Classification is based on the Unified Soli Classification System and ASTM Designations D-2487 and D•2488. Coarse Grained Soils have more than 50% of their dry weight retained on a 1200 sieve; they are described as: boulders, cobbles, gravel or sand. Fine Grained Soils have less then 50% of their dry weight retained On a 1200 sieve; they are described as: clays, if they are plastic, and sills if they are slightly plastic or non-plastic. Major eon. stituents may be added as modiliers and mint constituents may be added according to the relative proportions ..r- based on grain size. In addition to gradation, coarse grained soils are defined on the basis of their relative in-place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trade gravel. stiff (CL): silty sand, trace gravel, medium dense (SM). CONSISTENCY OF FINE-GRAINED SOILS: RELATIVE DENSITY OF COARSE•GRAINED SOILS: Unconfined Compressive N•Blows/lt. Relative Density Strength, Ou, psi Consistency 0.3 Very Loose 500 Very Soft 4.9 LOOMS 500 - 1,000 Soft 10.29 Medium Dense 1,001 . 2,000 Medium 30.49 Dense 50-80 Very Dense 4,001 - 4,000 Stiff 80+ Extremely Dense 4,001 - 8,000 Very Stiff 8,001 16,000 Hard .15,000 Vary Hard , GRAIN SIZE TERMINOLOGY RELATIVE PROPORTIONS OF SAND AND GRAVEL Major Component Descriptive Term(s) Of Sample Size Range (of Components Also Percent of Boulders Over 12 in. (300mm) Present In Sample) Dry Weight Cobbles 12 In, to 3 In. Trace < 15 (300mm to 75mm) 1rtllth 15 29 i GAevei 3 in. to #4 sieve Modifier r• 30 (75mm to 4.75mm) I Sand a4 to #200 sieve RELATIVE PROPORTIONS OF FINES (4 75mm to 0.075mm) Descriptive Terms) . Silt or Clay Passing #200 sieve lot Components Also Percent of (0.075mm) Present In Sample) Dry Weight Trace < 5 With 5 - 12 Modifier > 12 I A-3 liecracon. 05.02.96 11:51 $5rI484 Uasl EMPIRE LABS. Vb.)AO • LOG OF BORING NO. 1 Page 1 of 1 ctgxr ; ARCnlrsaf +On4EER Coulson Excavating I ThrrE Hwy. 402(County Rd. 54) IPROJECT Weld County, Colorado Gravel Excavating SAMPLES - TESTS pp J F m LL W •0 DESCRIPTION a. ftoo cc 15} z\ 6 ~~ - ? r niio i �� 5 a ht p•-LL CCU- CD Approx. Surface Elev.: ft. 0.5 6'TOPSOIL _ PA SILTY SAND Brown/orange/gray B 1.-s.- Moist to wet - Very loose I SS 12" 4 5.0 5 PA ;fie:* fi — 2 SS 12" 18 STlTY SAUQGRAVPI. 10 - PA ("sr 4:.; . AND COBBLES _ ` Cray, wet, medium dense.to dense — 3 SS 12' 16 a;' is - PA - - 4 SS 12' 40 20 PA ry - :?.':. 22.5 - WEA7iERED SII TSTONE _- 24.0 Gray, dry.hard —7 s SS 4" 50/4- 2" �STT TSTONE (I l3tay, dry.very hard END OF BORING i i TEE STRATIFICATION LIMES RE►AEstit TEE APPRGIIINTE aasoART LINES l""". UMW MIL AND NOOK TYPEsr IM-SITU, TIE TRANSITION MAY BE GRADUAL. WRING STAR773D 3-26-93 WATER LEVEL OINOLvATTo►Is A-4 wt if 3'-O„ w.D. 4 Empire Laboratories aORDTO COMPLETED 3-26-93 Incorporated RIO call -55 PonEMn1+ DAR Am. r DivtIWa of T<mcon APPROVED NRs 1OB/ 20935052 `M- Boles filled in A.B. SHEET NO. 13 WELD COUNTY, COLORADO, SOUTHERN I WOHN'TO1\N(?t'.4 '1 A' I E,•:'[.:ft II ill' I . . • fit �� r ^'��,�",1{�il�� ; 311. I, n,,,dwoA i ,,,,,t* s 4 fib 47 4 4. ir 44414. 41/4it. ' ti In 1 " , . b ' .&'� 1•tr .q '4Lry ail1.� iiiIrltrir dFb34 t ,,,,. , . #d"t gyp°{� I ' ,y, y 1. r 1 1*S + i + ' ( 4.' `its. �.�., , i N�:t� Ix r III Iir 43 '.:ir { 16 ' .m. 11�� t7 ' � NN: • u.. er f • 1F 4,1 3e i /I/79 "r i' 10441 ill • T. ll . row• _ N 1 ,�f 33 �' a L Qwewr 22 SOIL SURVEY The substratum to a depth of 60 inches is loamy sand and is Thissoil all crops commonl used almost yrely grownr irrigated crops.in the area, includ- sand. potatoes, �'' Permeability is rapid. Available water capacity is ing corn, sugar beets, beans,alfalfa, small grain, moderate. The effective rooting depth is 60 inches or and onions. An example of a suitable cropping system is 3 more. Surface runoff is slow, and the erosion hazard is to 4 years of alfalfa followed by corn, corn for silage, low. sugar beets, small grain, or beans. Land leveling, ditch This soil is used almost entirely for irrigated crops. It lining, and installing pipelines may be needed for proper is suited to all crops comnunonly grown in the area, in- water application. eluding corn, sugar beets, beans, alfalfa, small grain, All methods of irrigation are suitable, but furrow ir- tion is the most common. Barnyard manure and com- potatcea, and onions. An example of a suitable cropping rigs system is 3 to 4 years of alfalfa followed by corn,corn for mercial fertiliser are needed for top yields. or beans. Generally, such Windbreaks and environmental plantings are generally chara sugar beets, small grain,lyeristics as the rapidly permeable substratum suited to this soil. Soil blowing, the principal hazard in slgestablishing trees and shrubs, can be controlled by cul- s➢All restrict thod some crops. tivating only in the tree row and by leaving a strip of All methods of irrigation are suitable, but fonrow irr vegetation between the rows. Supplemental irrigation ge is the most common. Proper irrigation water may be needed at the time of planting and during dry managementr is essential.needed l. Barnyard manure and commer- periods.Trees that are best suited and have good survival vial Windbreaks ear are i for top yields. are Rocky Mountain juniper,eastern redeedar, Ponderosa and environmental the principal are hazard generally pins, Siberian elm, Russian-olive, and hackberry. The suited to this soil. Soil blowing, Principal hazard in shrubs best suited are skunkbush sumac, Mac, and Siberi- establishing trees and shrubs, can be controlled by cul- tivating only in the tree row and by leaving a strip of Wildlife is an important secondary use of this soil. The vegetation between the rows. Supplemental irrigation cropland areas provide favorable habitat for ring-necked may by needed at the time of planting and during dry pheasant and mourning dove. Many nongame species can periods.Trees that are best suited and have good survival be attracted by establishing areas for nesting and escape are Rocky Mountain juniper, eastern redeedar, ponderosa For pheasairta, undLtarbed nesting cover is as�ert- pine, Siberian elm, Russian-olive, and hackberry. The alaicover.and should be Inch dad lo plane far habitat develop- shrubs best suited are skunkbush sumac, lilac, and Siberi- ment,especially in areas of intensive agriculture. an peashrub. This soil has good potential far urban and recreational r Wildlife is an important secondary use of this soil. The development. Lawns, shrubs, and trees grow well. The cropland areas provide favorable habitat for ring-necked only limiting feature of this soil is the rapid permeability pheasant and mourning dove. Many nongame species can in the substratum, which rows a hazard of ground water be attracted by establishing areas for nesting and escape contamination from sewage lagoons. Capability subclass cover. For pheasants, undisturbed nesting cover is amen- IIe irrigated. tial and should be included in plans for habitat develop- i1—tiro leant, 0 to 1 percent slopes. This is a deep, ment, especially in areas of intensive agriculture. well drained soil on smooth plains and alluvial fans at This soil has good potential for urban and recreational elevations of 4,900 to 5,250 feet It formed in mixed eo➢an development Lawns, shrubs, and trees grow well. The deposits and parent sediment from a wide variety of only limiting feature of this soil is the rapid permeability bedrock. Included in mapping are small areas of sock that in the substratum,which causes a hazard of ground water have loamy sand underlying material. contamination from sewage lagoons. Capability subclass Typically the surface layer is brown and pale brown Its irrigated. about 12 inches thick.The upper 30 inches of the underly- 30—Julesburg sandy loam, 1 to 3 percent slopes. This ing material is pale brown loam. The lower part to a is a deep, well drained soil on terraces at elevations of depth of 60 liehea is pale brown fine sandy loam. 4,700 to 4,800 feet. It formed in alluvium deposited by the Permeability is moderate. Available water capacity is South Platte River. Included in mapping are some leveled high. The effective rooting depth is 60 inches or more. areas and small areas of soils that have a loamy sub- Surface runoff is slow,and the erosion hazard is low. stratum. This soil is used almost entirely for irrigated crops. It Typically the surface layer of this Julesburg soil is is suited to all crops commonly grown in the area, includ- brown sandy loam about 12 inches thick. The subsoil is ing cony sugar beets, beans, alfalfa, small grain, potatoes, brown and pale brown sandy loam about 15 inches thick. and onions. An example of a suitable cropping system is 3 The substratum to a depth of 60 inches is loamy sand and to 4 years of alfalfa followed by corn, corn for silage, sand. sugar beets, small grain, or.beans. Very few conservation Permeability is rapid. Available water capacity is practices are needed to maintain top yields. moderate. The effective rooting depth is 60 inches or All methods of irrigation are suitable, but furrow ir- more. Surface runoff is slow, and the erosion hazard is rigat n is the fertilizer are needed common. B top Barnyardyie mangy and coin- ,.-.. low. mercial WELD COUNTY, COLORADO, SOUTHERN PART 23 r ibreaks and environmental plantings of trees and The potential native vegetation is dominated by blue shr,.oe commonly grown in the area are generally well grams. Several mid grasses, such as western wheatgrass suited to this soil. Cultivation to control competing and needleandthread, are also present. Potential produc- vegetation should be continued for as many years as tion ranges from 1,600 pounds per acre in favorable years Trees that are best suited and to 1,000 pounds in unfavorable years. As range condition decrease; grams, buf- redcedar,have good followingsplanting.�q Mountain juniper, eastern deteriorates, the mid grasses and fringed blue sage have snakeweed, Yucca increase; hackberry. gler ponderosa pine, Siberian elm, skunRusskbush sumac,and andfa ra production drops. Undesirable weeds and an- The shrubs best suited are nuals invade the site as range condition becomes poorer. ��yb,lilac,and American plum. vegetation on this soil should be based areas an provide v favorable habitat a use of o this soil. The Management halfand leaving cropland for ring-necked on taking half of the total annual produc- pheasant and mourning dove. Many nongame species can tion. Seeding is gramsdesirable if the range is in poor condition. little blueatem, western wheatgrass, blue coat. For bya establishing areas for ing and escape SideSri pubescent wheatgrase,and crested wheatgrass are cover. For pheasants, undisturbed plans resting cover is essen- suitable for seeding. The grace selected should meet the mte and should n included in t si for habitat develop- seasonal requirements of tivestack. It can be seeded into meek soil es has epoch*in areas of potential for urban agriculture.andrea clean, firm sorghum stubble, or it can be drilled into a This e crea edtul gro and recreational firm prepared seedbed. Seeding early in spring has development.resulted Increased inc sh site co in t uct survey proven most successful in e increased ur homesite ucand The Windbreaks and environmental plantings of trees and area � development and road in the area are generally well ccons limiting feature for urbanshrubs commonly grown a load. Sept b the limited capacity d of the soil to support b suited to this soil. Cultivation to control competing c load.community sewage tank systems function properly,d the vegetation should be continued for as many years as s stems should be provided if the possible following planting. Trees that are bast suited and population Y Because of the permeability have good survival are Rocky Mountain juniper, eastern population density increases peolive, and of the substratum, sewage lagoons must be sealed. redcedar, ponderosa pine, Siberian elm, Russian Lawns shrubs, and trees grow well. Capability class I ir- rigated. hackberry. The shrubs best suited are skunkbush sumac, lilac,Siberian peashrab,and American plum. {m loam, I to 3 percent slopes. This is a deep, We is an important secondary use of this soil. The w rained soil on smooth plains and alluvial fans at upland area provide favorable habitat for ring-necked elevations of 4,900 to 5,250 feet. It formed in mixed eolian heasant and moiuning dove. Many nongame species can deposit and parent sediment from a wide variety of be attracted dry establishing areas for nesting and escape are small areas of soils that cover. For pheasants, undisturbed nesting cover is essen- have haveloa Included n mapping for habitat develop- loamy sand underlying material. tree and should be included in plans Range- loam the surface layer is brown and pale brown menu especially in areas of intensive agriculture. loam about 12 inches thick.The upper 28 inches of the un- land wildlife, for example, the pronghorn antelope, can be is brown loam. The lower part to a by developing livestock watering facilities, denying material pale attracted livestock grazing,and reseeding where needed. depth of ab inches ti i. r Availablebrown fine sandy loam. potential for urban and recreational Permeability is moderate. water capacity is +� soil has good in the survey high. The effective rooting depth is 80 inches or more. development. Increased population growth Surface runoff is medium,and the erosion hazard is low. area his resulted in increased homesite construction. The In irrigated areas this soil is suited to all crops com- chief limiting soil feature for urban development and road monly grown in the area, including corn, sugar beets, construction is the limited capacity of this soil to support beans, alfalfa, small grain,potatoes, and onions. An exam- a load. Septic tank absorption fields function properly,but 4 years of alfalfa community sewage systems should be provided if the fee of a suitable cropping system is $ to population density increases. Because of the permeability followed rby corn, corn for silage,h lining sugar(fig. . 6),beeta, small grain, sewage lagoons must be sealed. or beans. Land leveling, ditch (fl6. and installing of the substratum, Pipelines may be needed for proper water applications. Lawns, shrubs, and trees grow well. Capability subclass Loamy Pepin site. IVe nonirrigated; ns range This is a deep, All t men is e of comon are suitable, but furrow - lie irrigated, nt dopes. ligation is the most common. Barnyard manure and com- 33—Kim loam, 3 to 5 percent for top yields. well drained soil on plains and alluvial fans at elevations mercial fertilizer are neededthis to 5,250 feet. It formed in mixed eolian deposits In y, and Most soil is suited acreageto wpinter wheat,to of 4 parent 0 sediment from a wide variety of bedrock. In-barwinter is m of the edin is natetyd s and are small areas of soils that have winter wheat and is summer followed in alternate years cluded�underlying material. to allow moisture accumulation. Generally precipitation is loamy sally the in layer is brown and pale brown too low for beneficial use of fertiliser' T brown loam. The inches rfart u - �}r"+ble mulch farming, striperopping, and minimum til- loam about 10 inches thick.The upper 28 inches of the un- lag«. a needed to control soil blowing and water erosion. denying material is pale Terracing also may be needed to control water erosion. depth of 60 inches is pale brown fine sandy loam. WELD COUNTY, COLORADO, SOUTHERN PART 101 s'^ TABLE 6.--BUILDING SITE DEVELOPMENT--Continued , I Soil name and I Shallow I Dwellings , Dwellings 1 Small Local roads map symbol ! excavations I without : with , commercial and streets : basements basements buildings ___, , ____.1._ , ' 9 'Moderate: Severe: Severe: Severe: Severe: Colombo : floods. floods. floods. floods. floods. I 0 :Slight :Moderate: Moderate: Moderate: Moderate: Colombo : I low strength. low strength. , low strength. low strength, frost action. : I I 1, 22 :Severe: :Moderate: 'Slight Moderate: Severe: Dacono I cutbanks cave. I low strength, I low strength, shrink-swell, : shrink-swell. I shrink-swell. low strength. 3, 24 :Slight :Moderate: !Moderate: Moderate: Moderate: Fort Collins I 1 low strength. I low strength, low strength. low strength. : : shrink-swell. : : 5, 26 Severe: :Severe: :Severe: Severe: Severe: Haverson floods. I floods. I floods. floods. floods. I ! 7, 28 Severe: ,Severe: :Severe: Severe: Severe: Heldt too clayey. I shrink-swell, : shrink-swell, shrink-swell, shrink-swell, ' low strength. I low strength. low strength. low strength. 9, 30 Slight 'Moderate: 'Moderate: Moderate: Moderate: Julesburg ' low strength. I low strength. low strength. low strength, frost action. • , I 1 , 32 'Slight 'Moderate: ,Moderate: Moderate: Moderate: Kim ! ' low strength. I low strength. low strength. low strength. ! ' 3, 34 :Slight :Moderate: !Moderate: Moderate: Moderate: Kim'" I low strength. I low strength. low strength, low strength. I slope. : Se: ! Loup :Severe: 'Severe: ;Severe: Severe: Severe: I wetness, I wetness, I wetness, wetness, wetness. : cutbanks cave. I floods. I floods. floods. Boel 'Severe: :Severe: 'Severe: Severe: Severe: I wetness, wetness, I wetness, wetness, wetness, : floods, floods. I floods. floods. floods. I cutbanks cave. 6e: : Midway 'Severe: Severe: Severe: Severe: Severe: : too clayey. shrink-swell, shrink-swell, slope, shrink-swell , low strength. low strength. shrink-swell, low strength. low strength. : : Shingle !Severe: Severe: Severe: Severe: Severe: : depth to rock. depth to rock. depth to rock. depth to rock, depth to rock. slope. , $ 7 'Severe: Moderate: Severe: Moderate: Moderate: Nelson : depth to rock. depth to rock, depth to rock. depth to rock, depth to rock, low strength. low strength. low strength. ! : 8 !Severe: Moderate: Severe: Moderate: Moderate: Nelson ' depth to rock. depth to rock, depth to rock. slope, depth to rock, low strength. depth to rock, low strength. low strength. : 9, 40, 41 , 42, 43 Moderate: Severe: Severe: Severe: Severe: Nunn too clayey. shrink-swell, shrink-swell, shrink-swell, shrink-swell, low strength. low strength. low strength. low strength. /", 'ootnote at end of table. 112 SOIL SURVEY TABLE 9.--WATER MANAGEMENT--Continued /".i1 name and I Pond Embankments, Drainage I Irrigation Terraces Grassed ep symbol I reservoir dikes, and : and waterways areas levees , : diversions : : 20 :Seepage Low strength, :Floods, :Slope, Erodes easily Erodes easily. Colombo : , compressible. : slope. : erodes easily. : 21 , 22 :Seepage :Shrink-swell, :Slope, :Slow intake, Peres slowly--- Peres slowly. Dacono I I seepage, I percs slowly. I slope. I piping. 23 :Seepage Low strength---:Peres slowly---:Favorable :Favorable Favorable. Fort Collins 24 ISlope, Low strength---ISlope, :Slope ;Favorable Favorable. Fort Collins 1 seepage. : percs slowly. : 25 :Seepage ,Low strength, ;Floods :Floods :Floods, Favorable. Haverson I I compressible, I : : piping. I piping. : : 26 :Seepage :Low strength, :Slope :Slope Floods, Favorable. Haverson I I compressible, : 1 piping. I piping. : : 2T, 28 :Slope ILow strength, IPercs slowly, (Slope, IPercs slowly--- Peres slowly. Heldt I I shrink-swell. : slope. I percs slowly, I I slow intake. I 1 29 :Seepage :Seepage, :Favorable :Droughty :Soil blowing, Erodes easily. Julesburg I I piping, I I I piping. 1 I low strength. I I I I I I 30 :Seepage, :Seepage, :Slope :Droughty, :Soil blowing, Erodes easily. Julesburg I slope. I piping, I : slope, : piping. 1 I low strength. 1 I erodes easily.: 31^ :Seepage, :Piping, :Favorable :Favorable Slope, Slope. K. I slope. I low strength, I piping. : - I hard to pack. 1 I 32, 33, 34 :Seepage, :Piping, :Slope Slope Slope, :Slope. Kim I slope. I low strength, I piping. : : hard to pack. I $ I : I 35a: 1 I I I Loup :Seepage :Seepage, :Poor outlets, :Wetness, ,Wetness :Wetness. 1 piping. : outbanks cave.: seepage. I Boel :Seepage :Seepage, :Wetness, (Fast intake, Wetness, {Wetness, i 1 1 erodes easily,: floods, seepage, too sandy. 1 floods. I I piping. : poor outlets. wetness. 36.: I I I Midway ISlope, :Thin layer, :Complex slope, ,Complex slope, Slope, :Slope, 1 depth to rock,I shrink-swell, : depth to rock,: rooting depth, depth to rock,: percs slowly, 1 seepage. I low strength. I excess salt. I excess salt. poor outlets. : excess salt. Shingle :Slope, :Low strength, :Depth to rock, :Slope, Slope, :Slope, I depth to rock.: thin layer. : slope. I rooting depth. depth to rock.'. rooting depth. 37 :Depth to rock, :Piping, :Slope, :Slope, Depth to rock :Rooting depth. Nelson I seepage. I thin layer, I depth to rock.: rooting depth. : 1 low strength. 38 :Slope, :Piping, :Slope, :Slope, Slope, :Slope, Nelson I depth to rock,: thin layer, I depth to rock.: rooting depth. depth to rock. : rooting depth. I seepage. : low strength. I I I 39 :Favorable :Compressible,shrink-swell, IPercs slowly---IPercs' slowly---:Peres slowly---:Favorable. Nunn I I hard to pack. I I I - " wee footnote at end of table. 41 WELD COUNTY, COLORADO, SOUTHERN PART 125 TABLE 12.--ENGINEERING PROPERTIES AND CLASSIFICATIONS--Continued , , Classification IFrag- I Percentage passing 1 So- name and :Depth: USDA texture I Iments I sieve number-- :Liquid I Plea- map symbol - Unified AASHTO 1 > 3 1 I : I limit 1 tioity :inches: 4 10 I 40 1 200 I I index 1 Pct 1 I ; : Pct , : : : I : I, 15, 16, 17 0-7 :Loam CL-ML A-4 : 0 1100 100 190-100185-100: 25-30 1 5-10 olby 7-60:Silt loam, loam,,CL-ML A-4 0 1100 100 190-100185-100: 25-30 : 5-10 1 very fine sandy; I 1 : I : I loam. : I I : I :olby 0-7 Loam ICL-ML A-4 : 0 100 : 100 190-100185-1001 25-30 : 5-10 7-60 Silt loam, loam,ICL-ML ,A-4 0 : 100 1 100 190-100185-100: 25-30 I 5-10 very fine sandy; - : I : I 1 loam. : 1 1 I : 1 II I I 1 I : tdena I 0-6 ;Loam :ML IA-4 : 0 1100 1 100 190-100170-90 : 20-30 I NP-5 6-9 :Clay, clay loam,ICH, CL IA-6, A-71 0 : 100 1 100 :95-100180-90 1 35-60 115-35 : silty clay : , 1 loam. 1 : 1 : : I : 1 : : 9-60:Loam, silt loam,IML IA-4 0 1100 1100 190-100175-90 120-30 I NP-5 1 very fine sandy: I I I I I I : : loam. 1 : : I I 1 , , 1 I , 1, 20 1 0-14:Clay loam ICL-ML IA-4 I 0 195-100 80-100:75-90 150-70 125-30 : 5-10 ;olombo 114-21 :Clay loam, loam ICL IA-6 1 0 195-100 75-100:75-90 150-70 120-30 1 10-15 121-60:Stratified clay :CL, CL-MLIA-4, A-61 0-5 190-100 75-100 70-90 150-60 120-30 I 5-15 I I loam to sand. I I I : ; I , 22 1 0-12:Clay loam ICL, IA-6, A-4: 0 185-100175-10075-95 170-80 1 20-40 1 5-20 )acono 1 I : CL-ML : I 1 I I I 1 112-21 'Clay loam, clay,ICL IA-6, A-7: 0 175-100160-100 55-95 150-85 : 35-45 115-20 gravelly clay I 1 I I 1 I I I 1 loam. : : I 1 : , 1 I : :21-27 Sandy clay loam,ICL, SC IA-6 I 0 175-100160-100150-95 140-85 125-40 110-20 loam, silt : 1 I / ` loam. I : 1 1 I 127-601Very gravelly SP, GP 1A-1 1 0 35-80 1 5-50 15-40 10-5 1 --- I NP sand. I I I I I I 3, 24 1 0-7 ILoam CL-ML IA-4 I 0 95-100 90-100:85-100150-65 125-30 I 5-10 'art Collins 17-11 :Loam, clay loam CL IA-6 : 0 95-100 90-100 85-95 160-75 1 25-40 115-25 111-60:Loam, fine sandy,CL, CL-MLIA-4, A-6: 0 :95-100 90-100 80-95 150-75 : 25-35 1 5-15 I loam. : : I II I ;, 26 : 0-4 :Loam INL, CL-MLIA-4 : 0 :95-100180-100 75-90 :50-60 1 20-30 NP-10 laverson 4-60 Stratified clay :ML, CL-MLIA-4 I 0 195-100175-100 75-90 150-60 120-30 NP-10 : loam to sand. I I : I I I : : I : : I 28 1 0-60 Silty clay :CH, CL A-7 : 0 195-100195-100 95-100175-95 1 45-55 25-35 ieldt 1 : 1 1 I I II : ), 30 I 0-12 Sandy loam ISM, ML A-2, A-4: 0 95-100175-100 45-85 125-55 : --- NP l ulesburg 112-27 Fine sandy loam,ISM, ML A-2, A-4: 0 95-100175-100 50-85 130-55 1 15-25 1 NP-5 sandy loam. I I I : : I 127-60 Sandy loam, ISM A-2, 1 0 95-100:75-100 40-85 115-50 I --- : NP loamy sand, A-4, 1 1 1 fine sand. A-1 : 1 I 1 ' I, 32, 33, 34 0-12 Loam ML, SM A-4 1 0-5 90-100175-100 60-90 :45-75 , 20-35 I NP-5 tim 12-40 Loam, clay loam CL, CL-ML A-4, A-61 0-5 80-100175-100 70-95 160-85 125-40 1 5-15 40-60 Fine sandy loam SM, ML A-4 I 0-5 80-100175-100 70-95 140-55 ' 20-30 : NP-5 I I ie: 1 1 : soup 0-16 Loamy sand SM A-2 I 0 100 100 50-100115-30 I --- NP 16-60 Loamy sand, sand SP-SM, SM A-2, A-3: 0 100 100 65-1001 5-20 NP ' : : 3oel 0-14 Loamy sand SM A-2 1 0 100 100 85-95 :20-35 I --- NP 14-60 Fine sand, loamy SP, SM, A-2, A-31 0 100 100 85-95 1 0-25 I --- NP fine sand, SP-SM coarse sand. 1 1idway 0-13 Clay CL, CH A-7 I 0 100 100 90-100180-95 45-60 20-35 e"^ 13 Weathered --- ___ ___ __- ___ ___ I ___ _-_ --- bedrock. See footnote at end of table. 130 SOIL SURVEY TABLE 13.--PHYSICAL AND CHEMICAL PROPERTIES OF SOILS--Continued I I ; ; : I Risk_of corrosionT Erosion:Wind Soil name and Depth: Permea- 'Available: Soil :Salinity; Shrink- ; factorsat „..0+.., map symbol : bility : water :reaction : : swell :Uncoated Concrete ',--abilibilityy : :capacity I ; :potential 1 steel In 1 In/hr ; Tn/in !'N :Mmhos/cm: ----r-K �T :group_ 29, 30 1 0-12� 2.0-20 I l:0.11-0.151 6.6-7.8 : <2 :Low :Moderate Low 0.24 5 3 J ulesburg 112-27 2.0-20 10.11-0.151 6.6-7.8 : <2 :Lou :Moderate Low 0.24 127-60 >6.0 10.05-0.13; 6.6-7.8 : <2 :Low ;Moderate Low 0.20 I : : : l 31, 32, 33, 34 1 0-12 0.6-2.0 10.16-0.181 7.9-8.4 : <2 :Low :Moderate Low 0.32 5 4L Kim :12-60 0.6-2.0 10.15-0.17; 7.9-8.4 : <2 ;Low Moderate Low 0.32 I : , 354: : : ; Loup : 0-16, 6.0-20 10.10-0.141 6.6-8.4 <2 Low High Low 0.17 5 2 :16-601 6.0-20 10.06-0.08: 7.4-8.4 <2 Low High Low 0.17 I I Boel I 0-141 6.0-20 10.10-0.12 6.6-8.4 , <2 Low High Low 0.17 5 2 114-601 6.0-20 10.05-0.07 6.6-8.4 : <2 Low High Low 0. 17, : I : 364: I 1 ; , Midway 1 0-13:0.06-0.2 0.12-0.17 7.9-9.0 : 2-8 High High Low 0.43; 1 4 13 I --- --- --- ; ___ . l Shingle 0-6 10.6-2.0 0.16-0.18: 7.4-9.0 : <2 Low High Low 0.32 2 4L 6-18: 0.6-2.0 0.16-0.211 7.9-9.0 ; <2 Moderate High Low 0.49 , 18 1 ' I : : I : 37, 38 I 0-9 12.0-6.0 :0.13-0.151 7.9-8.4 : <2 :Low High Low 0.20 2 3 Nelson : 9-301 2.0-6.0 0.11-0.13: 7.9-8.4 <2 :Low High Low 0.20 130 1 --- 1 --- 1 --- --- 1 I : I : 39, 40, 41, 42 : 0-9 1 0.2-2.0 :0.15-0.201 6.6-7.8 <2 :Moderate Moderate Low 0.24 5 6 Nunn : 9-2910.06-0.6 :0.15-0.181 7.4-8.4 , <2 :High High Low 0.28 129-601 0.2-2.0 10.10-0.181 7.4-8.4 <2 :Moderate High Low 0.24 I : I : ;43 0-9 : 2.0-6.0 10.10-0.14: 6.6-7.8 <2 ;Low Moderate Low 0. 15 5 3 Nunn 9-29 0.06-0.6 0.15-0.181 7.4-8.4 <2 :High High Low 0.28 29-60 0.2-2.0 0.10-0.181 7.4-8.4 <2 ;Moderate High Low 0.24 r°w--'45 0-10 6.0-20 0.06-0.101 6.6-7.8 , <2 ;Low Low Low 0.17 5 2 .ey 10-20, 0.6-2.0 ,0.13-0.15 6.6-7.8 : <2 :Moderate High Low 0.24 20-251 0.6-6.0 10.11-0.15 7.9-8.4 1 <2 ;Low High Low 0.24 25-60: 2.0-6.0 :0.06-0.13 7.9-8.4 I <2 :Low High Low 0.20 : : : : 46, 47, 48 0-101 0.6-6.0 10.11-0.15 6.6-7.8 ; <2 :Low Moderate Low 0.20 5 3 Olney 10-201 0.6-2.0 :0.13-0.15 6.6-7.8 I <2 :Moderate High Low 0.24 20-251 0.6-6.0 10.11-0.15 7.9-8.4 : <2 :Low High Low 0.24 25-601 2.0-6.0 10.06-0.13 T.9-8.4 1 <2 ;Low High Low 0.20 : : 49 0-221 6.0-20 10.05-0.081 6.6-7.3 I --- :Low Low Low 0.10 5 1 Osgood ,22-341 2.0-6.0 10.10-0.131 6.6-7.3 : --- :Low ,Low Low 0.17 :34-60: 6.0-20 10.06-0.081 6.6-8.4 : <2 :Low :Moderate Low 0.10 : I I I : 50, 51 , 52, 53 1 0-12: 6.0-20 :0.09-0.13: 7.4-8.4 <2 Low :High Low 0.10 5 2 Otero 112-601 6.0-20 10.08-0.12: 7.4-8.4 <4 Low :High Low 0.10 : I I I 54, 55 1 0-201 0.6-2.0 10.16-0.18: 6.6-7.3 , --- :Low :Moderate Low 0.20 5 5 Paoli :20-251 >6.0 10.14-0.17: 7.4-7.8 I <2 :Low :High Low 0.20 125-601 >6.0 :0.12-0.141 7.4-8.4 <2 :Low 1High Low 0.20 : : : I , 56, 57 I 0-9 10.2-0.6 :0.17-0.211 6.6-7.8 <2 :Moderate :High Low 0.37 3 6 Renohill : 9-3210.06-0.2 ;0.14-0.161 6.6-8.4 <2 ;High ;High Low 0.32, 132 I --- I --- I --- --- 1 --- I I I I I : , I 58, 59 1 0-6 : 0.6-2.0 0.16-0.181 7.4-9.0 1 <2 ;Low :High Low 0.32; 2 4L Shingle 16-181 0.6-2.0 0.16-0.211 7.9-9.0 1 <2 :Moderate ;High Low 0.49; : 18 : --- ___ ___ 1 -__ 1 : ___ I : I 604: : : I Shingle 0-6 1 0.6-2.0 0.16-0.18 7.4-9.0 <2 :Low ;High Low 0.32; 2 4L , 6-181 0.6-2.0 0.16-0.21 , 7.9-9.0 <2 :Moderate ;High Low 0.49; 1 18 I --- ; ___ ___ ___ I , See footnote at end of table. 132 SOIL SURVEY TABLE 14.--SOIL AND WATER FEATURES t'-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 I High water table I Bedrock _ Soil name and Hydro-I I I I I Potential map symbol logic: Frequency I Duration Months I Depth Kind ;Months (Depth Hard- frost group : I ; : noes action : Ft : : In : I 1, 2 B None ' --- --- >60' --- Moderate. Altvan : : : 3*: : : : : : Aquolls : D Frequent----:Brief Apr-Jun:0.5-1.01Apparent:Apr-Jun: >60 --- High. I N Aquents D Frequent----:Brief Apr-JunI0.5-1.0:ApparentlApr-Junl >60 --- High. I Aquolls D (Frequent----:Brief Apr-Jun10.5-1.51ApparentlApr-Jun: >60 I --- High. Aquepts I D :Frequent----:Brief Apr-Junl0.5-1.5IApparent:Apr-Junl >60 I --- High. 5, 6, 7, 8, 9 I B :None I --- --- >6.0 : --- I --- I >60 --- Moderate. Ascalon 10 A (Frequent---- Brief Mar-Jun >6.0 --- : --- I >60 --- Low. Bankard 11 , 12 B ;None --- --- >6.0 --- : --- ; >60 --- Moderate. Bresser 13 A ;None --- --- >6.0 , --- : --- : >60 : --- Low. Cascajo I I : 14, 15, 16, 17---- B :None --- --- >6.0 : --- I --- I >60 I --- Low. Colby ^" I , 1 I : 1 : I I Colby : B :None --- --- : >6.0 I --- I --- : >60 I --- Low. : I Adena I C :None --- --- I >6.0 I --- I --- : >60 1 --- Low. I I 19, 20 I B :Rare --- --- : >6.0 : --- I --- I >60 --- Moderate. Colombo I ; : I I I , 21, 22 : C :None --- --- : >6.0 --- I --- I >60 --- Low. Dacono I 23, 24 I B :None to rare --- --- : >6.0 : --- I --- I >60 : --- Low. Fort Collins 25, 26 ' B :Rare to Brief May-Sep: >6.0 , --- : --- >60 I --- Low. Haverson : : common. 27, 28 : C None --- --- >6.0 ; --- : --- >60 --- Low. Heldt : 29, 30 ; A None --- --- >6.0 : --- I --- ' >60 --- Moderate. Julesburg 31 , 32, 33, 34----I B ,None --- --- >6.0 : --- ; --- I >60 --- Low. Kim I i : 35a: I : I Loup : D :Rare to Brief Mar-Jun +.5-1.5 Apparent Nov-May: >60 --- Moderate. : common. : I : Boel I A (Occasional Brief Mar-Jun 11.5-3.5:Apparent Nov-May: >60 --- Moderate. 36"; , Midway D ;None --- --- : >6.0 I --- --- I10,21Y Rip- Low. pable , , r"-- See footnote at end of table. 9.2 Table 9.1.--Runoff curve numbers for hydrologic soil-cover complexes (Antecedent moisture condition II) and Ia = 0.2 S) '— Cover Land use Treatment Hydrologic Hydrologic soil group or practice condition ABCD Fallow Straight row ---- 77 86 91 94 Poor 72 81 88 91 Row crops Good 67 78 85 89 Contoured Poor 70 7 79 84 88 Good 82 86 "end terraced Poor 66 74 80 82 " " n Good 62 71 78 81 Small Straight row Poor 65 76 84 88 63 75 83 87 grain Good 63 74 82 85 Contoured Poor Good 61 73 81 84 61 72 79 82 "and terraced Poor Good 59 70 78 81 66 77 85 89 Close-seeded Straight row PoorGood 58 72 81 85 it n legumes Poor 64 75 83 85 or Contoured 69 78 83 rotation Good 55 63 73 8o 83 _ meadow "and terraced Poor 51 67 76 83 0,""‘ "and terraced Good Poor 68 79 86 89 Pasture Fair 49 69 79 84 or range Good 39 61 74 80 Contoured Poor 47 67 81 88 it Fair 25 59 75 83 " Good 6 35 70 79 Meadow Good 30 58 71 78 Poor 66 77 83 Woods Fair 36 6o 73 79 Good 25 55 70 77 Farmsteads --- 59 74 82 86 Roads (dirt) J ---- 72 82 87 89 (hard surface) J --- 74 84 90 92 J Close-drilled or broadcast. 21 Including right-of-way. 9.8 Table 9.3.--Runoff curve numbers for hydrologic soil-cover complexes in Puerto Rico (antecedent moisture condition II, and Ia = 0.2 S). Hydrologic soil group Cover and condition ABCD Fallow 77 86 91 93 Grass (bunch grass, or poor stand of sod) 51 70 80 84 Coffee (no ground cover, no terraces) 48 68 79 83 Coffee (with ground cover and terraces) 22 52 68 75 Minor crops (garden or truck crops) 45 66 77 83 Tropical kudzu 19 50 67 74 Sugarcane (trash burned; straight-row) 43 65 77 82 Sugarcane (trash mulch; straight row) 45 66 77 83 Sugarcane (in holes; on contour) 24 53 69 76 Sugarcane (in furrows; on contour) 32 58 72 79 Table 9.4.-Runoff curve numbers for hydrologic soil-cover complexes of a typical watershed in Contra Costa County, California (antecedent moisture condition II, and Ia m 0.2 S). Hydrologic soil group ( I Cover Condition A B C D s-" i Scrub (native brush) ---- 25-30 41-46 57-63 66 Grass-oak (native oaks with Good 29-33 43-48 59-65 67 understory of forts and annual grasses) Irrigated pasture Good 32-37 46-51 62-68 70 Orchard (winter period with Good 37-4i 50-55 64-69 71 understory of cover crop) Range (annual grass) Fair 46-49 57-60 68-72 74 Small grain (contoured) Good 61-64 69-71 76-80 81 67-6 74 76 80-83 84 Truck crops (straight-row) Good Urban areas: 69-71 75-78 82-84 86 Low density (15 to 18 per- cent impervious surfaces) Medium density (21 to 27 per- 71-73 77-80 84-86 88 cent impervious surfaces) High density (50 to 75 percent 73-75 79-82 86-88 90 impervious surfaces) 356 APPENDIX D-1 RUNOFF CURVE NUMBERS D-1 Runoff Curve Numbers Curve number for Cover description hydrologic soil gcoaP— Avenge percent Cover type and hydrologic condition impervious area' A B C I) Polly developed urban areas(vegetation established) Open space(lawns,parks,golfs cemeteries, etc.)': 68 79 86 8B Poor condition( al al cover < 60%) d Fair condition(grass cover 69 79 84 cover 50%to 75%) 89 61 74 8 Good condition(grass cover > 76%) Impervious areas: Paved perking lots,roofs,driveways,etc. (excluding right-of-way) 98 98 98 98 Streets and roads: Paved;curbs and storm sewers(excluding 9e 98 98 right-of-way) 98 89 92 98 Paved;open ditches(including right-of-way) 88 86 89 91 Gravel Wading right-of-way) 76 82 89 91 Dirt((nduding right-of-way) Western desert urban areas: gg 77 85 98 Natural desert landscaping(pervious areas only)'..• Artificial desert landscaping.(kupervious weed barrier,desert shrub with 1-to finch sand 96 96 96 96 or gravel mulch and basin borders). Urban districts: 89 9E 94 96 CommercW 86 and business 86 81 88 91 98 Industrial Residental districts by average hot me. b 77 85 90 8 92 1/8 sere or less(town houses) 6B 61 76 88 97 1/4 acre 80 67 72 81 86 ll8 a 25 64 70 80 85 1l9 acre e 20 61 96 % 79 77 84 2 acre --/�toc 12 if- E acres Developing urban areas Newly graded areas(pervious areas only, 77 86 91 94 no vegahtlsi)' Idle lands(CN's are determined using cover types similar to those ht table&g4 'Avenge nova,condition,and I, -OM. CN'a Other eesnmptbae are u follow:ingwn'lus erase aloe aveea{e percent impervious ores shown was used to develop the :ho er i Own e re directly casnseted to the dnssne's'stem Impervious arw have a of OB.sod�pseniars arw are om)deed rya e paee in good hydrologic cantles ON's for ether aadMesd na of condition May tor other easing Ige of apes gees cover type• 'Cone shown are tor natural to those of e• • Said be gMd radar apses 14 or 24 hosed en the bapavhse mea percentage(CN a MO and the b CN's lhogs ems CN.She drag pervious to desert drub lot poor Imedegle condition. 'Compodte ■to use for the design et tawotwl mares dating gvadia[and corsnbut dwM be saputed slag Mar Y-9 or 24, bred on the degree of development(impervious sea percentage)and the ON"for the randy graded pervious cam �. Figure D-1.(Chart 1) Runoff curve numbers. (Courtesy of Soil Conservation Service, Technical Release 55.) :hapter 6 Storage Volume for Detention Basins Technical Release 66 Urban Hydrology for Small Watersheds Input requirements and Estimating V, Procedures Use worksheet 6a to estimate V.,storage volume Ise figure 6-1 estimate storage volume(V,)required or required,by the following procedure. teak outflow discharge(qa).The most frequent appli • - • ation is to estimate V.for which the required inputs 1. Determine qo.Many factors may dictate the selec • - re runoff volume(V),q ,and peak inflow discharge tion of peak outflow discharge.The most common q).To estimate qo,the required inputs are Vr,V. is to limit downstream discharges to a desired nd qi. level,such as predevelopment discharge.Another factor may be that the outflow device has already been selected. 2. Estimate 4 by procedures in chapters 4 or 5.Do not use peak discharges developed by other proce- dure. When using the Tabular Hy►drograph method to estimate qi fora subarea,only use peak dis- charge associated with T1=0. figure 6-1 Approximate detention basin routing for rainfall types I,IA,II,and ID namom .6 . - ! ! - I ---. • 4 , • .5 ;a„madpd, ..-.-_ - '-- �� . -- i ff' t1 }> 4 ru , t is i t t a _ ..... } 3 I n cc : . i , f ► i t - F ' 3 s • r l4.....;- 1 .1 121 .3 .4 .5 .6 ,7 .8 Peak outflow discharge qo Peak inflow discharge { qi } i 8-2 (210-Vl-TR-65,Second Ed.,June 1986) Hello