HomeMy WebLinkAbout20042913 ALLE& Associates
Memo
To: Project File-Borrego 0301
Front George D. Paulsberg, P.E.
Date: 12/5/03
Re: Soils Evaluation
A review of the on site soils has been made based on the "Soil survey of Weld County, Colorado—
Southern Part." By: United States Department of Agriculture Soil Conservation Service in cooperation
with Colorado Agriculture Experiment Station.
The reference map is map 15 for the Southern part and a copy is attached.
The soils shown on the map for the site are: 1-Midway-Shingle;4-Wiley-Colby-Weld; 75-Vona sandy
loam and 76-Vona sandy loam. See the soil survey manual—southem part for a detail description of
these soil types.
1-Midway-Shingle soils are found on the northern 1/3 of the site where the planned development is
planned.
4-Wiley-Colby-Weld soils are located in the middle 1/3 of the site where existing oil production facilities
are located. The wetness of this soil group does not effect these facilities except for access at certain
times of the year.
75 & 76-Vona sandy loam are located on the southern 1/3 portion of the property. No development is
planned here except an access road.
Table 6"Building Site Development"of the Soils Survey Manual defines 1-Midway-Shingle type of soil
as moderate ratings for dwellings, small commercial buildings and local roads. Moderate means
acceptable with engineering. The other three soil groups will only have an access road construction on
them as an overlaid type construction.
Table 7"Sanitary Facilities"of the Soils Survey Manual defines 1-Midway-Shingle type soil as slight for
septic tank and absorption fields. Slight means acceptable provided the water table and the bottom of
the leach field can maintain the proper separation distamce.
Table 8"Construction Materials"of the Soils Manual defines the soil as good to poor for use as road fill.
The road to be built is only an access road for access to the site and not a through or public road. The
construction planned will be an overlaid fill on existing soil with culverts where needed.
Table 13 "Physical and Chemical Properties of Soils" of the Soils Survey Manual rates 1-Midway-
Shingle soil type as good in permeability. The planned location in the NE corner for the site detention
pond for run-off control will provide good percolation of the run-off and minimize this impact on the
development.
It is my conclusion that the on site soils are very compatible to the planned development of the site.
1
2004-2913
WELD COUNTY, COLORADO, SOUTHERN PART :3
`l. Midway-Shitikle
limn•, moderately sloping hi strongly slop,)y/, well
,..linrr! clays and Ion its 'braid( in rvsirAuun from cal-
rCirrollS mina e
This moderately to strongly sloping map unit is in 'the r 75-Vona sandy loam, 0 to 1 percent slopes. This is a
southwestern part of the survey area. It is on the ridge deep, well drained soil on high terraces at elevations of
crests and side slopes along Coal Creek and its 4,650 to 4,950 feet. It formed in alluvial deposits. Included
drainageways. It makes up less than 1 percent of the in mapping are some leveled areas and small areas of
total acreage. About 40 percent is Midway soils. 35 per- soils that have a loamy substratum.
cent is Shingle soils, and 25 percent is soils of minor es- Typically the surface layer of this Vona soil is grayish
tent. brown sandy loam about 10 inches thick. The subsoil is
Midway and Shingle soils occupy similar positions on brown fine sandy loam about 20 inches thick The sub-
the landscape. Midway soils have a clay surface layer and stratum to a depth of 60 inches is sandy loam.
underlying material. Shingle soils have a loam surface Permeability is moderately rapid. Available water
layer and clay loam underlying material. Roth soils are capacity is moderate. The effective rooting depth is 60
underlain by calcareous shale at depths of ID to 20 inches. inches or more. Surface runoff is slow, and the erosion
Minor in this unit are the well drained Renohill and hazard is low.
Lim soils. There are also small sandstone outcrops. This soil is used almost entirely for irrigated crops. It
This map unit is used mainly for rangeland. Small areas is suited to all crops commonly grown in the area, includ-
have been cultivated. Shallowness is the main limitation ing corn, sugar beets, beans, alfalfa (fig. 7), small grain,
in fanning. The potential is fair for development of ran- potatoes, and onions. An example of a suitable cropping
geland wildlife habitat. system is 3 to 4 years of alfalfa followed by corn, corn for
silage, sugar beets, small grain, or beans. The rppidly
permeable substratum slightly restricts some crops.
4. Wiley-Colby-Weld All methods of irrigation are suitable, but furrow ir-
Deep, nearly level to moderately sloping, well drained silt rigation is the most common. Proper irrigation manage-
ment is essential Barnyard manure and commercial fertil-
.- izer are needed for top yields.
This nearly level to moderately sloping map unit is on
plains in the west-central and southwestern parts of the Windbreaks and environmental plantings are generally
survey area. It makes up about 5.5 percent of the total suited to this soil. Soil blowing, the principal hazard in
acreage. About 30 percent is Wiley soils, 30 percent is establishing trees and shrubs, can be controlled by cul-
Colby soils, 15 percent is Weld soils, and 25 percent is tivating only in the tree row and by leaving a strip of
soils of minor extent vegetation between the rows. Supplemental irrigation
Wiley and Colby soils form an intermingled complex may be necessary at the time of planting and during the
pattern on the steeper side slopes. Weld soils are along dry periods. Trees that are best suited and have good
the narrow ridgetops and on the nearly level side slopes. survival are Rocky Mountain juniper, eastern redcedar,
Wiley soils have a silt loam surface layer and a silty clay ponderosa pine, Siberian elm, Russian-olive, and hackber-
loam subsoil Colby soils have a loam surface layer and ry.The shrubs best suited are skunkbush sumac, lilac, and
silt loam underlying material Weld soils have a loam Bur- Siberian peashrub.
face layer and a clay loam subsoil. Wildlife is an important secondary use of this soil.
Minor in this unit are the moderately well drained Ring-necked pheasant, mourning dove, and many non-
Heldt soils and the well drained Nunn and Ulm soils. game species can be attracted by establishing areas for
This map unit is used mainly for cropland. About 70 nesting and escape cover. For pheasants, undisturbed
percent is irrigated and is well suited to all commonly nesting cover is essential and should be included in plans
grown crops. In nonirrigated areas, winter wheat is the for habitat development, especially in areas of intensive
principal crop. The potential is fair for urban develop- agriculture.
ment. Moderately slow permeability is the main limits- This soil has. good potential for urban and recreational
tion. The potential is also fair for development of open- development. Lawns, shrubs, and trees grow well. The
land wildlife, only limiting feature is the rapid permeability in the sub-
stratum, which causes a hazard of ground water con-
tamination from sewage lagoons. Capability subclass Its
irrigated.
WELD COUNTY, COLORADO, SOUTHERN PART
76—Vona sandy loam, 1 to 3 percent slopes. This is a
deep, well drained soil on plains and high terraces at
elevations of 4,600 to 5,200 feet. It formed in eolian and
alluvial deposits. Included in mapping are some leveled
areas. Also included are small areas of soils that have a
loamy substratum and areas of soils that are noncalcare-,
ous to a depth of 60 inches.
Typically the surface layer of this Vona soil is grayish
brown sandy loam about 10 inches thick. The subsoil is
brown fine sandy loam about 18 inches thick. The sub-
stratum to a depth of 60 inches is sandy loam.
Permeability is moderately rapid. Available water
capacity is moderate. The effective rooting depth is 60
inches or more. Surface runoff is slow, and the erosion
hazard is low.
In irrigated areas this soil is suited to all crops com-
monly grown in the area, including corn, sugar beets,
beans, alfalfa, small grain, and onions. An example of a
suitable cropping system is 3 to 4 years of alfalfa fol-
lowed by corn, corn for silage, sugar beets,small grain,or
beans. Land leveling, ditch lining, and installing pipelines
are needed for proper water applications.
All methods of irrigation are suitable, but furrow r-
rigation is the most common. Barnyard manure and com-
mercial fertilizer are needed for top yields.
Windbreaks and environmental plantings are generally
suited to this soil. Soil blowing, the principal hazard in
establishing trees and shrubs, can be controlled by cul-
tivating only in the tree row and by leaving a strip of
vegetation between the rows. Supplemental irrigation
may be necessary at the time of planting and during dry
periods.Trees that are best suited and have good survival
are Rocky Mountain juniper, eastern redcedar, ponderosa
pine, Siberian elm, Russian-olive, and hackberrv. The
shrubs best suited are skunkbush sumac, lilac, and Siberi-
an peashrub.
Wildlife is an important secondary use of this soil. The
cropland areas provide favorable habitat for ring-necked
pheasant and mourning dove. Many nongame species can
be attracted by establishing areas for nesting and escape
cover. For pheasants, undisturbed nesting cover is essen-
tial and should be included in plans for habitat develop-
ment, especially in areas of intensive agriculture. Range-
land wildlife, for example, the pronghorn antelope, can be
attracted by developing livestock watering facilities,
managing livestock grazing,and reseeding where needed.
This soil has good potential for urban and recreational
development. Lawns, shrubs, and trees grow well. The
only limiting feature is the rapid permeability in the sub-
stratum, which causes a hazard of ground water con-
tamination from sewage lagoons. Capability subclass IIe
irrigated; IVe nonirrigated; Sandy Plains range site.
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