FLOOD10335

• County: Mesa
• Stream Name: Indian Wash
• Basin: Colorado Mainstem
• Title: Watershed Work Plan - Indian Wash Watershed, Mesa County, CO
• Date: 9/1/1961
• Prepared By: Upper Grand Valley Soil Conservation District
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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This work plan outlines a three-year project for installation of
land treatment and structural measures for the protection of the water-
shed. The estimated total project cost is $482,166. The Public Law
566 share of this cost will be $431,586. Funds from other sources will
be $50,580 and include local funds as well as funds available under
other Federal authority. In addition, local organizations will bear
the entire cost of operation and maintenance of the structural measures.
This is estimated to be $2,387 annua~ly.

Land Treatment Measures'

Approximately 5,735 acres of the upper watershed area is public
rangeland under the administration of the U. S. Bureau of Land Management.
The cost of proposed land treatment to be applied by the Bureau of Land
Management in this area over a two-year period is estimated to be $46,530.
The Public Law 566 share will be $40,530, and other funds will amount to
$6,000.

Of the 2,490 acres of privately-owned agricultural land, 1,260
acres are irrigated cropland and 1,230 acres are desert rangeland. The
cost of proposed land treatment' on these lands over a three-year period
is estimated to be $46,600. The Public Law 566 share will be $3,000,
and $43,600 ~nll be obtained from other funds.

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Structural Measures

One floodwater-retarding structure having a total storage capacity
of 1,615 acre-feet is proposed on Indian Wash above the area subject to
damage. Of the total capacity, 1,045 acre-feet is allotted to floodwater
detention and 570 acre-feet to sediment storage. The flooa~ater
detention capacity is equivalent to 3 inches of stor.m runoff fram the
watershed area controlled and will provide flood protection framstor.ms
occurring less frequently than once in a hundred years. The principal
spillway flow fram this structure will be carried to the Colorado River
through the existing Indian Wash channel. The total cost of the flood-
water-retarding structure not including operation and maintenance is
estimated to be ~389,036. The average annual cost including operation
and maintenance is $16,447.

The sponsors will contract for construction of the floodwater-
retarding structure and will furnish personnel and funds for administrnt.ion
of the contract. The costs involved in obtaining land, easements, and
rights-of-way for the proposed structure will be borne by the sponsors.

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