Quick viewing(Text Mode)

Mansfield Dam and Lake Travis

Mansfield Dam and Lake Travis

Corps of Engineers, Dept. of the Army, DoD § 208.19

§ 208.19 Marshall Ford and Res- conditions, the following upstream ervoir ( and Lake U.S. Geological Survey gaging stations Travis), , Tex. are used as indicators of the magnitude The Secretary of the Interior, of the inflows to Marshall Ford Res- through his agent, the Lower Colorado ervoir: River Authority (LCRA) shall operate (i) Colorado River near San Saba the Marshall Ford Dam and Reservoir (08147000). in the interest of control as fol- (ii) near Johnson lows: City (08153500). (a) Water Control Plan—(1) General ob- (iii) at Llano (08151500). jectives. The objectives of the Marshall (3) Standing instructions to dam tender. Ford Reservoir () are the During normal conditions, the dam improvement of navigation, flood con- tender will regulate the project in ac- trol, stream regulation, generation of cordance with instructions received power, irrigation, water supply, and from the LCRA System Operator. Dur- recreation uses. ing flood conditions, when the Marshall (2) Overall plan for water control. Ford Reservoir level is within the flood Within the Colorado River Basin, four control zone, the LCRA System Oper- Federal projects provide flood control ator will regulate the project in ac- protection: Twin Buttes, O. C. Fisher, cordance with instructions received Hords Creek, Marshall Ford Reservoir. from the Corps of Engineers. In the The considerable distance (328 river event of a communication outage, the miles) and large intervening area LCRA System Operator will rely on the (19,990 square miles) separating Mar- Emergency Release Schedule, to make shall Ford Reservoir and the three changes in the rate of releases from the upper basin flood-control projects pre- lake. vent realizing any significant benefits (4) Flood control regulation—(i) Gen- from coordinating releases to control eral. At all times, releases shall be co- the inflow into Marshall Ford. Mar- ordinated such that the Colorado shall Ford Reservoir is the fifth project River, , will be controlled when in a tandem of six lakes operated and possible, to remain below control controlled by the Lower Colorado River stages at downstream official U.S. Geo- Authority for the generation of hydro- logical Survey (USGS) gaging stations; electric power. These six projects in except that no curtailment of normal downstream order are: , hydroelectric turbine releases shall re- Lake Inks, Lake Lyndon B. Johnson sult thereby at any time. The USGS (Alvin ), river stations and their control stages (Max Starcke Dam), Marshall Ford are as follows: Reservoir (Lake Travis and Mansfield KEY DOWNSTREAM CONTROL POINTS Dam) and Lake (). The releases from each of the six Equivalent Control cubic feet projects are closely coordinated by the Station stage per second LCRA System Operation Control Cen- (feet) (c.f.s.) ter. Three of the projects (Lake Inks, Austin (08158000) ...... 20.5 30,000 Lake Marble Falls, and ) 1 24.8 1 50,000 are run-of-the-river projects. The Bastrop (08159200) ...... 25.1 45,000 capabiity of the four upstream lakes to 1 26.7 1 50,000 control the inflow of flood water into Columbus (08161000) ...... 25.5 50,000 Marshall Ford depends on their ante- 1 Control stage when elevation 710 is forecast to be exceeded. cedent lake elevations. The majority of inflows to Marshall Ford are comprised Forecasted reservoir inflows and the of the mainstream flows of the Colo- upstream USGS gaging stations rado River, the tributary flows of the Pedernales River near Johnson City Llano River (entering the Colorado (08153500), Llano River at Llano River between Lakes Inks and Lyndon (08151500), and Colorado River near San B. Johnson) and the unregulated tribu- Saba (08147000) will be considered when tary flows of the Pedernales River (en- scheduling flood releases. tering between Lake Marble Falls and (ii) Flood control release schedule. Mar- Marshall Ford Reservoir). During flood shall Ford will be regulated to reduce

125

VerDate Mar<15>2010 08:18 Aug 02, 2012 Jkt 226134 PO 00000 Frm 00135 Fmt 8010 Sfmt 8010 Y:\SGML\226134.XXX 226134 emcdonald on DSK67QTVN1PROD with CFR § 208.19 33 CFR Ch. II (7–1–12 Edition)

flooding on the Colorado River below trol stages on the Colorado River as the dam. This plan of regulation will specified in paragraph (a)(4)(i) of this govern flood control releases from Mar- section. These release rates will be shall Ford Dam as follows: maintained until the reservoir level (A) Elevation 681–683. If the reservoir falls below elevation 685 feet, m.s.l. level is forecast to rise above elevation (D) Elevation 691–710. Should the res- 681 feet, m.s.l. (top of conservation ervoir elevation be forecast to exceed pool) but not to exceed elevation 683 691 feet, m.s.l. (the top of the joint use feet, m.s.l., the releases shall be in- pool) but not to exceed elevation 710 creased to 3,000 c.f.s. and maintained feet, m.s.l: Releases will be made at until the reservoir level recedes to ele- 30,000 c.f.s. from the project or at a rate vation 681 feet, m.s.l. These release such that, when combined with local rates may need to be reduced due to ex- inflows below the dam, will equal but cessive downstream runoff to prevent not exceed downstream control stages exceeding the control stages specified on the Colorado River as specified in in paragraph (a)(4)(i) of this section. paragraph (a)(4)(i) of this section. (B) Elevation 683–685. If the reservoir These release rates will be so con- elevation is forecast to rise above ele- trolled until the reservoir level falls vation 683 feet, m.s.l. but not to exceed below elevation 691 feet, m.s.l. elevation 685 the releases shall be in- (E) Elevation 710–714. If the reservoir creased to 5,000 c.f.s. and maintained level is forecast to exceed 710 feet, until the reservoir level recedes below m.s.l. but not to exceed elevation 714 683 feet, m.s.l. These release rates may feet, m.s.l: Releases will be made at need to be reduced due to excessive 50,000 c.f.s. from the project or at a rate downstream runoff to prevent exceed- such that, when combined with local ing the control stages specified in para- inflows below the dam, will equal but graph (a)(4)(i) of this section. (C) Elevation 685–691. Seasonal. (1) not exceed the downstream control During the months of January through stages on the Colorado River as speci- April, July through August, and No- fied in paragraph (a)(4)(i) of this sec- vember through December: If the res- tion. These release rates will be main- ervoir elevation is forecast to rise tained until the reservoir level falls above elevation 685 feet, m.s.l. but not below elevation 710 feet, m.s.l. to exceed elevation 691, the releases (F) Elevation 714–722. If the reservoir shall be increased to 5,000 c.f.s. and level is forecast to exceed 714 feet, maintained until the reservoir level re- m.s.l. but not to exceed 722 feet, m.s.l: cedes below 683 feet, m.s.l. These re- Releases will be made at 90,000 c.f.s. lease rates may need to be reduced due from the project. Releases shall not ex- to excessive downstream runoff to pre- ceed the associated peak flood res- vent exceeding the control stages spec- ervoir inflow. ified in paragraph (a)(4)(i) of this sec- (G) Elevation 722 and above. If the res- tion. ervoir level is forecast to exceed ele- (2) During the months of May, June, vation 722 feet, m.s.l., the Bureau of September, and October: Should the Reclamation will schedule releases as reservoir elevation be forecast to ex- required for the safety of the structure. ceed 685 feet, m.s.l. but not to exceed (iii) Normal flood control regulation elevation 691 feet, m.s.l: Releases will schedule. The following table, Flood be made at 30,000 c.f.s. from the project Control Regulation Schedule, summa- or at a rate such that, when combined rizes the flood control releases sched- with local inflows below the dam, will ule for given reservoir levels and river equal but not exceed downstream con- conditions:

MARSHALL FORD DAM AND RESERVOIR NORMAL FLOOD CONTROL REGULATION SCHEDULE

Condition Reservoir level Flood control release Control points

Pool Rising ...... Forecast: 681–683 1 ...... 3,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... Forecast: 683–685 ...... 5,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus.

126

VerDate Mar<15>2010 08:18 Aug 02, 2012 Jkt 226134 PO 00000 Frm 00136 Fmt 8010 Sfmt 8010 Y:\SGML\226134.XXX 226134 emcdonald on DSK67QTVN1PROD with CFR Corps of Engineers, Dept. of the Army, DoD § 208.19

MARSHALL FORD DAM AND RESERVOIR NORMAL FLOOD CONTROL REGULATION SCHEDULE— Continued

Condition Reservoir level Flood control release Control points

Do ...... Forecast: 685–691:. (a) During January, February, March, 5,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. April, July, August, November, De- cember. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. (b) During May, June, September, Oc- 30,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. tober. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... Forecast: 691–710 ...... 30,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... Forecast: 710–714 ...... 50,000 c.f.s ...... 50,000 c.f.s. (24.8 ft.) at Austin. 50,000 c.f.s. (26.7 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... Forecast: 714–722 2 ...... 90,000 c.f.s ...... No controls. Do ...... Forecast: above 722 ...... The Bureau of Rec- lamation will specify the releases for safety of the struc- ture. Pool Falling ...... Above 722 ...... do. Do ...... 722–714 2 ...... 90,000 c.f.s ...... No controls. Do ...... 714–710 ...... 50,000 c.f.s ...... 50,000 c.f.s. (24.8 ft.) at Austin. 50,000 c.f.s. (26.7 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... 710–691 ...... 30,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... 691–685: ...... 30,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. (a) During May, June, September, Oc- tober. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. (b) During January, February, March, 5,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. April, July, August, November, De- cember. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... 685–683 ...... 5,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. Do ...... 683–681 ...... 3,000 c.f.s ...... 30,000 c.f.s. (20.5 ft.) at Austin. 45,000 c.f.s. (25.1 ft.) at Bastrop. 50,000 c.f.s. (25.5 ft.) at Columbus. 1 During flood conditions, when the reservoir level is below elevation 681 ft., m.s.l., the Corps of Engineers will provide rec- ommendations to the Lower Colorado River Authority on flood control releases. 2 Releases shall not exceed the associated peak flood reservoir inflow. NOTE: No curtailment of normal hydroelectric turbine releases shall be required due to flood control operations.

(5) Deviation from normal regulation. shall be confirmed in writing the same (i) There are occasions when it is nec- day to the project owner and shall in- essary or desirable to deviate from the clude justification for the action. water control plan for short periods of (B) The project owner may tempo- time as indicated in the following para- rarily deviate from the water control graphs: plan in the event an immediate short- (A) The water control plan is subject term departure is deemed necessary for to temporary modification by the emergency reasons to protect the safe- Corps of Engineers, if found necessary ty of the dam, or to avoid serious haz- in time of emergency. Requests for and ards. Such actions shall be imme- action on such modifications may be diately reported by the fastest means made by the fastest means of commu- of communication available. Actions nication available. The action taken shall be confirmed in writing the same

127

VerDate Mar<15>2010 08:18 Aug 02, 2012 Jkt 226134 PO 00000 Frm 00137 Fmt 8010 Sfmt 8010 Y:\SGML\226134.XXX 226134 emcdonald on DSK67QTVN1PROD with CFR § 208.22 33 CFR Ch. II (7–1–12 Edition)

day to the Corps of Engineers and shall day-second-feet average for the pre- include justification for the action. vious 24 hours, ending at midnight. Continuation of the deviation will re- (C) Computed average inflow, in day- quire the express approval of the Chief second-feet for the previous 24 hours, of Engineers, or his duly authorized ending at midnight. representative. (D) Total precipitation in inches for (C) Advance approval of the Chief of the previous 24 hours at the dam, end- Engineers, or this duly authorized rep- ing at 0800 hours. resentative, is required prior to any de- (E) Summary of streamflow and viation from the plan of regulation pre- channel conditions at gages named in scribed or approved by the Corps of En- paragraphs (a)(2) and (a)(4)(i) of this gineers in the interest of flood control section. and/or navigation, except in emergency (ii) Lake Buchanan Pool elevation at situations provided for in paragraph 0800 hours. (a)(5)(i)(B) of this section. When condi- (2) Whenever flood conditions are im- minent, or stages of 16 feet (20,000 c.f.s.) tions appear to warrant a prolonged de- or more at the Austin gage have been viation from the approved plan, the reached, the Authority shall report at project owner and the Corps of Engi- once to the District Engineer by the neers will jointly investigate and fastest means of communications evaluate the proposed deviation to in- available. Data listed in paragraph sure that the overall intergrity of the (b)(1) of this section shall be reported plan would not be unduly com- to, and at intervals prescribed by the promised. Approval of prolonged devi- District Engineer for the duration of ations will not be granted unless such flood surveillance and control oper- investigations and evaluations have ations. been conducted to the extent deemed necessary by the Chief of Engineers, or (Sec. 7, Pub. L. 78-534, 58 Stat. 890 (33 U.S.C. his designated representative, to fully 709)) substantiate the deviations. [44 FR 24552, Apr. 26, 1979; 44 FR 29050, May (ii) The Fort Worth District Corps of 18, 1979] Engineers will serve as the LCRA con- § 208.22 Twin Buttes Dam and Res- tact point for any deviation from or ervoir, Middle and South Concho modification of the water control plan. Rivers, Tex. The communication network will be The Bureau of Reclamation, or its described in the Water Control Manual. designated agent, shall operate the The Fort Worth District will notify the Twin Buttes Dam and Reservoir in the Division Engineer, Southwestern Divi- interest of flood control as follows: sion, Corps of Engineers of any devi- (a) Whenever the Twin Buttes Res- ations or modifications of the water ervoir level is between elevations control plan and request his approval. 1,940.2 (top of conservation pool) and The Division Engineer has been des- elevation 1,969.1 (top of flood control ignated as the authorized representa- pool) the flood control discharge facili- tive of the Chief of Engineers in mat- ties shall be operated under the direc- ters relating to projects within the tion of the District Engineer, Corps of Southwestern Division which are sub- Engineers, Department of the Army, in ject to provisions of Section 7 of the charge of the locality, so as to reduce 1944 Flood Control Act. as much as practicable the flood dam- (b) Reports to the Corps of Engineers. age below the reservoir. All flood con- (1) The Authority shall furnish the Dis- trol releases shall be made in amounts trict Engineer, Fort Worth District, which, when combined with releases U.S. Army Corps of Engineers, by 0900 from San Angelo Reservoir on the hours daily, with the following: North and local inflow (i) Project information. below the dam, will not produce flows (A) Lake elevations at midnight and in excess of bankful capacities on the 0800 hours. South Concho and Concho Rivers down- (B) Uncontrolled spillway, flood-con- stream of the reservoir. In order to ac- trol conduits, and turbine releases: complish this purpose, flows shall not Cubic feet per second at 0800 hours, and exceed a 22.5-foot stage (25,000 c.f.s.) on

128

VerDate Mar<15>2010 08:18 Aug 02, 2012 Jkt 226134 PO 00000 Frm 00138 Fmt 8010 Sfmt 8010 Y:\SGML\226134.XXX 226134 emcdonald on DSK67QTVN1PROD with CFR

Top View