WSP08310

• File Number: 8220.124.A
• Description: Pine River
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 7/1/1965
• Author: Pine River Soil Cons
• Title: Watershed Work Plan: Pine River Watershed La Plata and Archuleta Counties Colorado
• Water Supply Pro - Doc Type: Report/Study

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Fiscal Year
First
Second
Third
Fourth
Fifth
Total

". S true ture
P. L. 566 Other
$113,800 :$13,100
49,800 32,600
56,700 37,000

Land Treatment

$ 220,300 : $ 82,700*

P. L. 566
$ 10,300
17,300
19,500
9,400
4,300
$ 60,800

Other
:$ 36,500
63,100
100,400
57,700
36,200
:$293.900

* In addition to the stated local cost share, the estimated present
value of the lands, easements and rights-of-way represented by
the 30 mUes of main canals is $81,500.

EFFECTS OF WORKS OF IMPROVEMENT

The principal effects of the application of watershed land treat-
ment, the construction of two floodwater-retarding structures, and the
rehabilitation of the distribution system will be increased local and
regional benefits through stabilization of crop production and the
conservation and application of water. None of the crops produced in
this area are in surplus. Significant effects will include: (1) a
reduction in floodwater and sediment damages below the two floodwater-
retarding structures, (2) some reduction in the floodwater, erosion,
and sediment damages over all the approximately 12,200 acres of
irrigated lands, and (3) a general .improvement in watershed soil and
cover conditions for the future. The potential for interruption of
irrigation services will be materially reduced by the structural
program.

The regulated releases of the reservoirs provide for emptying
each of the reservoirs in about two days. The average capacity of
the outlet works at FR-l is 13 c.f.s. and at PR-2 is 23 c.f.s. These
flows can be handled by the existing downstream channel and road
bridges and culverts.

In addition to the road, bridge, and canal damage reduction, the
installation of these structures is estimated to reduce the flood-
plain irrigated acres subject to flooding (25-year frequency) after
land treatment from 313 acres to 108 acres. These damage reductions
will be produced by the reduction of flood peaks. For a 25-year
frequency storm, the peak discharge will be reduced from 1,866 c.f.s.
to tube flow immediately below PR-l with about 237 c.f.s. unreser-
voired peak flows entering below, and from 2,250 c.f.s. to tube flow
immediately below PR-2 and with about 188 c.f.s. unreservoired peak
flows entering downstream. Existing stream channels will contain
these peak discharges.