PERMFILE41171

• Permit No: M1996082
• IBM Index Class Name: Permit File
• Doc Date: 10/28/1996
• Doc Name: 112 PERMIT APPLICATION BLAIR MESA GRAVEL PIT RIO BLANCO CNTY
• From: CORN CONSTRUCTION CO
• To: DMG
• Media Type: D
• Archive: No

•
Rio Blanco County Area, Colorado
1880 with the establishment of Powell Park Ditch. The
principal irrigation ditches along the White River and its
tributaries were constructed in the 1880's and 1890's.
Agriculture in the survey area today is diversified. It
consists of growing irrigated pasture and hay, irrigated
field crops, and nonirrigated field crops and raising
sheep and cattle. This results in a fairly stable
agricultural economy in the area. Approximately 4
percent of the survey area is irrigated cropland, about
1.6 percent is nonirrigated cropland, and about 61
percent is rangeland. The county is predominately
federally administered land. About 73 percent of the total
acreage is administered by the Bureau of Land
Management and the Forest Service. The state of
Colorado administers 1.5 percent of the county for
wildlife and recreational uses.
The main nonirrigated crops are wheat and barley.
Wheat usually is grown on about 60 percent of the
nonirrigated cropland. This varies yearly depending on
factors such as market conditions, soil moisture content,
and climate, The majority of the wheat is planted every
other year in fall under awheat-fallow cropping system.
The nonirrigated cropland is in the eastern half of Rio
Blanco County.
The main irrigated crops are alfalfa and grass hay.
Some oats are also grown, and approximately 200 acres
of com for silage is grown in the Rangely area. Most of
the ircigation is done by contour ditch flooding; however,
leveled land along the White River is irrigated by the
border method. A few acres are irrigated by sprinkler
systems.
Livestock enterprises are an important part of the
agriculture in this survey area. Privately owned and
federally administered rangeland provides grazing late in
spring and in summer and provides winter range for
sheep in the western part of the area. The livestock
operations are primarily of the cow-calf and ewe-Iamb
type. A few operations depend entirely on raising
yearlings.
Gradually, the number of farms and ranches is
declining and the size of the individual units is
increasing. The demand for agricultural land for other
uses is also increasing.
The Douglas Creek Soil Conservation District was
formed in 1945. It served the western third of the county.
In 1946 two additional districts were organized in the
eastern two-thirds of the county. They were the Lower
White River and the Upper White River Soil Conservation
Districts. In 1964 these two districts were consolidated
into the White River Soil Conservation District.
climate
Prepared >»' the NaGOnal Climatic Center, Asheville, North Carolina.
In the Rio Blanco County Area, summers are warm or
hot in most valleys but are much cooler in the
5
mountains. Winters are cold in the mountains. The
valleys are colder than the lower slopes of adjacent
mountains because of cold air drainage. Precipitation
occurs in the mountains throughout the year, and a deep
snowpack accumulates in winter. Snowmelt usually
supplies much more water than can be used for
agriculture in the survey area. In the valleys, precipitation
in summer falls as showers and some thunderstorms. In
winter the ground is covered with snow much of the
time. Chinook winds, which blow downslope and are
warm and dry, often melt and evaporate the snow.
Table 1 gives data on temperature and precipitation
for the survey area, as recorded at Rangely, Meeker,
and Little Hills, Colorado, for the period 1951 to 1974.
Table 2 shows probable dates of the first freeze in fall
and the last freeze in spring. Table 3 provides data on
the length of the growing season. These tables show the
climatic variability among various localities at different
elevations in the area.
In winter, the average temperature is 20 to 24 degrees
F and the average daily minimum is 5 to 10 degrees.
The lowest temperature on record, -48 degrees,
occurred at Little Hills on January 12, 1963. In summer,
the average temperature is 63 to 69 degrees and the
average daily maximum is 83 to BB degrees. The highest
temperature, 108 degrees, was recorded at Rangely on
June 21, 1974.
Growing degree days, shown in table 1, are equivalent
to "heat units." Beginning in spring, growing degree days
accumulate by the amount that the average temperature
each day exceeds a base temperature (40 degrees). The
normal monthly accumulation is used to schedule single
or successive plantings of a crop between the last
freeze in spring and the first freeze in fall.
Of the total annual precipitation, 55 percent usually
falls during the period April through September, which
includes the growing season for most crops. Two years
in ten, the rainfall in April through September is less than
5.17 inches. The heaviest 1-day rainfall during the period
of record was 2.00 inches at Rangely on June 10, 1970.
About 35 thunderstorms occur each year, 21 of which
are in summer,
Average seasonal snowfall is 40 to 80 inches. The
greatest snow depth at any one time during the period of
record was 30 inches. On an average of 15 to 30 days,
at least 1 inch of snow is on the ground. The number of
such days varies greatly from year to year.
The average relative humidity in midafternoon is less
than 33 percent in spring and is about 44 percent the
rest of the year. Humidity is higher at night year-round,
and the average at dawn is about 59 percent. The sun
shines 77 percent of the time possible in summer and 61
percent in winter. The prevailing wind is Trom the east-
southeast. Average windspeed is highest, 10 miles per
hour, in June.