WSP06117

• File Number: 8583
• Description: Rio Grande Decision Support System
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 1/1/1988
• Author: Steven J. Shupe & Jo
• Title: The Upper Rio Grande: A Guide To Decision-Making
• Water Supply Pro - Doc Type: Publication

MAJOR RESE~V()IRS
OFTRE
UPPER BASIN

"

f

El Vado Dam (shown before conslru~io'( at r~cenl.hydropmper,fr;ciiilieS).
PHdro BY PAUL LOGSOQN.

if

~
L
"
16

13

plies, municipal uses, and meeting
Compact obligations all play roles in
today's management decisions.

I
I
i::
I',

:'

1. COCHITI DAM OPERATION' As
explained in the previous section,
Cochiti Dam is the backbone of flood
control on the mainstem of the Rio
Grande. Under the 1960 Flood Con,
trol Act, the primary purpose of the
reservoir was to prevent damage to
downstream lands from floodwater.
However, Congress also authorized
the storage of San ]uan-Chama water
in Cochiti in order to maintain a per-
manent pool for recreational pur-
poses and for fish and wildlife. As a
result of this authorization, enough
SIC water is retained each year to
maintain a reservoir surface of 1,200
acres.

:.'

to.

I
I
I

Cochiti frequently stores significant
amounts of spring and early summer
runoff that would otherwise cause
downstream flooding. The dam is
operated with the primary goal of
releasing the stored water as quickly
as possible without causing down-
stream damage. Because the capacity
of the Rio Grande channel through
Albuquerque and the MRGCD region
is about 7,000 to 8,000 cubic feet per
second (ds), releases from Cochiti
combined with those from the Jemez
Canyon Dam are generally kept
below this flow rate, Also, the Corps
of Engineers operating manual for
these darns states that such releases
shall, if possible, be held to such a
rate that all the flow that reaches San
Acacia can be passed through the
2,000 cfs conveyance channel that
detours the riverbed leading to Ele.
phant Butte Reservoir.

In accordance with the 1960 Flood
Control Act, Cochiti operating criteria
constrain releases during the months
of July through October to prevent
the MRGCD from diverting water
that belongs to irrigators below Ele.
phant Butte. When the natural flow
into Cochiti Reservoir (as measured at
Otowi Bridge) falls below 1,500 crs, no
releases of stored flood water can
generally be made from Cochiti. If
excess waters were evacuated during
this low flow period, the irrigators