WSP04624

• File Number: 8220.145.A
• Description: La Plata Project ‎(New Mexico)‎
• Basin: San Juan/Dolores
• Date: 4/1/1944
• Author: USDOI/BOR
• Title: La Plata Project: Colorado-New Mexico - Project Investigations Report No. 32-A
• Water Supply Pro - Doc Type: Report/Study

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FLOOD CONTROL

Floods

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Sovoro floods aro known to havo occurrEd. on La Plata River in 1904,
1909, 1911, 1927, and 1930, rosulting in destruction of ditch diversion
works and groat damago to crops and property, especially below the
state lino. Studies of flood frequency and ratos of run-off led to
the conclusion that flood control capacity of 15,000 acre-feet should
be provided in State Lino Reservoir. Designs of the dam are based on
this amount for flood control.

Since the principal floods are of the summer cloudburst type and
will come without warning, whon tho irrigation storage capacity may be
filled, flood control capacity must bo separate from' and in addition
to, irrigation capacity. An open spillway of restrictod sizo would be
utilized to control outflow and yet assure emptying of flood control
capacity promptly.

Damages and Bonefits

Tho Corps of Enginoors, Unitod Statos War Dopartment, estimated
flood damago and bonefits as follows:

Estimatod Flood Damago and Benefits

La Plata Project in New Moxico

Number of Floods
in 100 yoars
1
3
6
33
37

Estimated Damage
Per Flood Total
$141,000 $ 141,000
68,000 204,000
49,000 294,000
19,000 627,000
9,000 333,000
$1,599,000
16,000
Line Res. 1,100
$ 14,900,

Total
Mean yearly damage
Damage not preventable by Stato
Mean annual flood benefit

Flood benofi t from crop increase due
to elimination of service intorruptions
Total benpfit

Roughly

5,200
20,100
$ 20,000

The value of surcharge I;ltorago for flood control uso would ju-stify
participation in the first cost of tho reservoir in the amount of
$400,000.

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