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<br />Problems
<br />
<br />Problems
<br />
<br />More intensive use of the agricultural lands and crops is limited because
<br />of the frequency of'flooding. Presently there are no land use or zoning
<br />restrictions to prevent residential and commercial development in flood
<br />prone areas.
<br />
<br />Agricultural Land and Crop Damage
<br />under present conditions all storm frequencies cause land, crop and
<br />property damage within the flood plain area. The following table indi-
<br />cates the breakdown of land use by several storm frequencies.
<br />
<br />Frequency of Flooding
<br />Damaging floods have occurred on Boxelder Creek on an average of once
<br />every year to once every three years, according to local records and
<br />statements frOOl local land owners and tenants covering 65 years. In
<br />this period of record, 24 damaging storms have occurred. These floods
<br />occurred throughout the entire watershed. In addition to the major
<br />events quite a few localized storms occur over the irrigated land caus-
<br />ing floodwater, sediment and erosion damages that are largely unprevent-
<br />able.
<br />
<br />Storm
<br />Frequency
<br />100 Yr.
<br />10 Yr.
<br />2 Yr.
<br />
<br />Flood Plain
<br />Area Ac.
<br />7,182
<br />4,646
<br />2,008
<br />
<br />Flood Plain Land Use
<br />Irng. Ac. ~Ac. Misc, Ac.
<br />5,437 1,135 610
<br />3,517 734 395
<br />1,520 317 171
<br />
<br />Floods of Record
<br />Floods occurred in 1969, 1967, 1965, 1963, 1961, 1947, 1941, 1937, 1933,
<br />1930, 1922, 1909 and 1904. Generally damages on agricultural land begin
<br />to occur about the 2-year frequency or SO percent chance storm and
<br />damages to rural land and property begin wi th the 5-year frequency or
<br />20 percent chance storm.
<br />
<br />Nearly all of the flood plain area requires debris removal after flood-
<br />ing. Highest land and crop damage is on the irrigated land where field
<br />irrigation systems and leveled grades are destroyed or damaged and must
<br />be replaced. Crop damage to sugar beets, dry beans, com, alfalfa and
<br />small grain is extensive in the flood path.
<br />
<br />Infonnation obtained in August 1969 frOlTl land ~rs in the flood plain
<br />for the years 1959 through 1969 indicate that flood damage occurs s<:me-
<br />where in the watershed each year. Estimated damage frCl1l these storms
<br />follOOf:
<br />
<br />.
<br />,
<br />,
<br />i
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<br />Main distribution system canals are occasionally damaged by larger floods
<br />as occurred above Wellington in 1961. Canal crossings at streams are de-
<br />signed to be flood proof frem the smaller more frequent storms.
<br />Total average annual agricultural floodwater damage is estimated at
<br />$64,860 of Which $51,020 is crop and pasture, $13,840 is other agricul-
<br />tural.
<br />
<br />August 1, 1961, one SO to 100-year frequency storm in the v1C1n1ty of
<br />\I'ellington, Colorado. Forty basements were flooded in addition to agri-
<br />a.l1tural and non-agricultural crops a.nd property, with damages estimated
<br />at $76,150.
<br />
<br />Private and Public Properties
<br />There are 27 county road crossings subject to damage frOl'll the lOO-year
<br />frequency storm. Flooding will occur on the re<:ently cmrpleted Inter-
<br />state Highway 2S frCJll about the lO-year frequency storm with flows
<br />along borrow pits and with some lIIinor overtopping of the roadways. No
<br />lo.rge flows have occurred in the past two years.
<br />
<br />June 1963, one 25 to SO-year frequency stonn over a very 5IIIall area.
<br />Estilllated damages $7,200.
<br />
<br />There are 93 residences and 18 cOllJllercial properties in the loo-year
<br />frequency storm flood plain in the tCllffi of Wellington. With the recent
<br />rate of expansion in the watershed, an additional 900 acres of residential
<br />development in the 100-year flood plain areas downstream from Wellington
<br />is expected in the future.
<br />F:i.ooJwattlt J.."..."",:; to pri~lIte ami public properties amount to $61,030
<br />annually. Of this $20,500 1S road and bridge damage, $34,930 is pro-
<br />perty damage in the town of Wellington, and $5.600 is damage to the
<br />Wellington Wildlife Area.
<br />
<br />June 14 . 17, 1965, one 2-year, two I-year and one 25-year frequency
<br />storms with sane overlapping of areas. Estimated damage $96,000,
<br />May 30 and June 4, 1967, two 25-year frequency storms - overlapping
<br />over a relatively small area in the vicinity of Wellington, Colorado.
<br />Estimated dll.l1\3.ges of $46,100 with four lives lost at a county road
<br />bridge washout.
<br />
<br />August 4, 1969, a I-year frequency storm occurring over a small area.
<br />D8IIIlIges are estimated at $4,000,
<br />
<br />Sediment and Erosion
<br />
<br />Principal sediment and erosion damages are concurrent with flood flows.
<br />There is some active channel erosion in the steep upper reaches of Boxelder
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