WSP07823

• File Number: 8443.200
• Description: Narrows Unit - Mailing Lists Correspondence
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 9/1/1961
• Author: US DoI BoR
• Title: Site Selection Report
• Water Supply Pro - Doc Type: Report/Study

2315

,.

Hoyt Reservoir

A preliminary estimate made for Hoyt Reservoir on Bijou Creek
shows a cost of $7,900,000 at February 1961 prices.

The reservoir would be located about 4 miles south~st of Ha,rt,
Colorado, and would submerge the abandoned NUe Reservoir.
Construction requirements would consist of about 6 miles of dams
and dilres extending across Bijou, Antelope and Little Antelope
Creeks. The crest elevation would be 4,840 feet and the maximum
height of fill above ground about 50 feet. Space allocations in
the reservoir are shown in the following table 113.

Table 113 -- Allocation of Capacity

Pool

Elevation--
tOf of pool
feet)

'.

Dead
Sediment (50 years)
Conservation
Flood Control
Superstorae;e

'*

o
25,000
11,000
24,000
40,000

o
25,000
36,000
60 ,000
100,000

4,819
4,823
4,829
4,836

'..

* Streambed elevation at Bijou Creek is about 4,805 and at Antelope
Creek about 4,790 feet.

A 110,000 cfs grassed spillllaY would be located at the right abutment
and would discharge into Muddy Creek drainage. The spillway would
be about 2 miles long with a bottom width of 2 {ooo feet. The inflow
desie;n flood has a peak of 180,000 cfs and a 22 day volume of
177,000 acre-feet.

There would be separate outlet works for Bijou Creek and for
,\ntelope Creek with a combined capacity of 1,000 cfs ,/hen the reservoir
water surface is at the top of the flood pool--elevation 4,829 feet.
The Corps of Engineers has requested 22,000 acre-feet of flood control
space for an average release rate of 5,000 cfs. On a judgement basis
it was assumed to be more economical to use a smaller release and
correspondin(lly larger flood pool than that indicated by the Corps.
During normal operations the release rate to both creeks would be
no greater than the quanti ty ~1hich could be absorbed by the channel
for ground water recharge.

Deficiencies in criteria used 1n the above design estimate are:

"..,

50 years sedilDent allocation instead of 100 years
MiniIrrum riprap and. freeboard
No key trench
No downstreaIu slOpe protection from spUls
No concrete control in the grassed spill~~

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