[Code of Federal Regulations]
[Title 33, Volume 3]
[Revised as of July 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 33CFR208.22]

[Page 119-120]
 
                TITLE 33--NAVIGATION AND NAVIGABLE WATERS
 
         CHAPTER II--CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY
 
PART 208--FLOOD CONTROL REGULATIONS--Table of Contents
 
Sec. 208.22  Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex.

    The Bureau of Reclamation, or its designated agent, shall operate 
the Twin Buttes Dam and Reservoir in the interest of flood control as 
follows:
    (a) Whenever the Twin Buttes Reservoir level is between elevations 
1,940.2 (top of conservation pool) and elevation 1,969.1 (top of flood 
control pool) the flood control discharge facilities shall be operated 
under the direction of the District Engineer, Corps of Engineers, 
Department of the Army, in charge of the locality, so as to reduce as 
much as practicable the flood damage below the reservoir. All flood 
control releases shall be made in amounts which, when combined with 
releases from San Angelo Reservoir on the North Concho River and local 
inflow below the dam, will not produce flows in excess of bankful 
capacities on the South Concho and Concho Rivers downstream of the 
reservoir. In order to accomplish this purpose, flows shall not exceed a 
22.5-foot stage (25,000 c.f.s.) on

[[Page 120]]

the USGS gage on the Concho River near San Angelo, Tex. (river mile 
60.9); or a 22.8-foot stage (25,000 c.f.s.) on the USGS gage near Paint 
Rock, Tex. (river mile 19.6).
    (b) When the Twin Buttes Reservoir level exceeds elevation 1,969.1 
(top of flood control pool), releases shall be made at the maximum rate 
possible and continued until the pool elevation recedes to elevation 
1,969.1 when releases shall be made to equal inflow or the maximum 
release permissible under paragraph (a) of this section, whichever is 
greater.
    (c) The representative of the Bureau of Reclamation in immediate 
charge of operation of the Twin Buttes Dam shall furnish daily to the 
District Engineer, Corps of Engineers, Department of the Army, in charge 
of the locality, a report, on forms provided by the District Engineer 
for this purpose, showing (1) for Twin Buttes Reservoir, the elevation 
of the reservoir level; number of river outlet works gates in operation 
with their respective openings and releases; uncontrolled spillway 
releases; storage; reservoir inflow; available evaporation data; and 
precipitation in inches; and (2) for Nasworthy Reservoir, the elevation 
of the reservoir level; irrigation outlet works and controlled spillway 
releases; storage; tailwater elevation; and reservoir inflow. Normally, 
one reading at 8 a.m. shall be shown for each day. Readings of all items 
except evaporation shall be shown for at least three observations a day 
when the Twin Buttes Reservoir level is above elevation 1,940.2. 
Whenever the Twin Buttes Reservoir level rises to elevation 1,940.2 and 
releases for flood regulation are necessary or appear imminent, the 
Bureau representative shall report at once to the District Engineer by 
telephone or telegraph and, unless otherwise instructed, shall report 
once daily thereafter in that manner until the reservoir level recedes 
to elevation 1,940.2. These latter reports shall reach the District 
Engineer by 9 a.m. each day.
    (d) The regulations of this section insofar as they govern use of 
the flood control storage capacity in Twin Buttes Reservoir above 
elevation 1,940.2 are subject to temporary modification in time of flood 
by the District Engineer, if found desirable on the basis of conditions 
at the time. Such desired modifications shall be communicated to the 
representative of the Bureau of Reclamation in immediate charge of 
operations of the Twin Buttes Dam by any available means of 
communication and shall be confirmed in writing under date of the same 
day to the Regional Director in charge of the locality, with a copy to 
the representative in charge of the Twin Buttes Dam.
    (e) Flood control operation shall not restrict releases necessary 
for municipal, industrial, and irrigation uses.
    (f) Releases made in accordance with the regulations of this section 
are subject to the condition that releases shall not be made at rates or 
in a manner that would be inconsistent with emergency requirements for 
protecting the Twin Buttes Dam and Reservoir from major damage or 
inconsistent with safe routing of the inflow design flood (spillway 
design flood).
    (g) The discharge characteristics of the river outlet works (capable 
of discharging approximately 32,470 c.f.s. with the reservoir level at 
elevation 1,969.1) shall be maintained in accordance with the 
construction plans (Bureau of Reclamation Specifications No. DC-5274 as 
modified by revised drawings and criteria in Designers' Operating 
Criteria, Twin Buttes Dam, dated February 1963).
    (h) All elevations stated in this section are at Twin Buttes Dam and 
are referred to the datum in use at that location.

[31 FR 12521, Sept. 22, 1966]