Water Resources in Texas
History of the Watershed Program
The Flood Control Act of 1936 (Public Law 74-738) authorized providing watershed protection and flood prevention as a complement to the downstream flood control program of the Corps of Engineers. Preliminary examinations were initiated on 212 watersheds nation wide. Detailed survey reports were prepared recommending the installation of watershed improvement programs in 25 watersheds from this list. The Flood Control Act of 1944 (Public Law 78-534 or PL 78-534) authorized the installation of works of improvement contained in 11 of the detailed survey reports. Two of the 11 authorized watersheds are located entirely in Texas: the Middle Colorado River and the Trinity River. A portion of a third authorized watershed, the Washita River, is located in Texas and Oklahoma.
In 1953 the House and Senate Agricultural Appropriations Committees obtained an appropriation of $5 million for a "pilot" watershed program. The Secretary of Agriculture by Memorandum 1325, dated April 1, 1953 established the "Pilot Watersheds Program" and assigned responsibility to the Soil Conservation Service (SCS) which approved 62 watersheds in 33 states. Four of the Pilot Watersheds were located in Texas: Cow Bayou, Green Creek, Calaveras Creek, and Escondido Creek. All 62 of the planned floodwater retarding structures in these four watersheds were installed and are now in the operation and maintenance phase.
The Watershed Protection and Flood Prevention Act of 1954 (Public Law 83-566 or PL 83-566) authorized a permanent nationwide program to provide technical and financial assistance to local watershed groups willing to assume responsibility for initiating, carrying out, and sharing in costs of upstream watershed conservation and flood control. Since the Law's inception in 1954, Texas has had 99 PL-566 watershed plans approved, of which nine have been deauthorized.
Resources, General, Conditions and Needs
Texas NRCS is coordinating efforts with other resource agencies to achieve maximum conservation accomplishments. NRCS employees regularly attend Texas Association of Watershed Sponsors and National Watershed Coalition meetings to coordinate watershed program activities with organization goals. NRCS works closely with the Texas Commission on Environmental Quality- Dam Safety Program on hazard classification reviews of all dams and formal inspections of high hazard dams.
Texas has all or part of 20 major land resource areas covering 168 million acres. Average annual rainfall varies from 5 inches on the west to 55 inches on the east. Seasonal patterns exist but frequent droughts and major storms of high intensity are common. The state has pressing needs for the development of additional water supplies and wastewater treatment. At the same time, the state ranks near the top nationally in the amount of flood insurance claims paid, flood insurance coverage, and flood insurance policies in effect.
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Authorized (PL-534) Watersheds
The Washita River Watershed in Texas consists of one approved subwatershed plan which has been completed. All 38 of the planned floodwater retarding structures have been constructed and are in the operation and maintenance phase.
The Middle Colorado River Watershed consists of 17 approved subwatershed plans of which 14 have been completed. All 227 planned floodwater retarding structures in the completed subwatersheds have been constructed and are in the operation and maintenance phase. In the three remaining active subwatersheds, 49 of the 53 planned floodwater retarding structures have been constructed.
The Trinity River Watershed contains 33 approved subwatershed plans of which four were approved for land treatment practices only. All four of the land treatment only watershed plans have been completed. Two of the subwatersheds are considered to be inactive due to lack of sponsor interest and/or activity. Of the remaining 27 approved subwatershed plans, 14 have completed all 213 of the planned floodwater retarding structures. In the 13 remaining active subwatersheds, 696 of the 868 planned floodwater retarding structures have been constructed.
Nine of the 99 approved PL-566 watershed plans have been deauthorized, leaving 90 approved plans. Seven of the remaining 90 watershed plans contain only land treatment conservation measures. All of the contracts have expired.
The 83 remaining watershed projects that contain structural measures include 65 watershed plans that have completed all 203.2 miles of planned channel improvement, all 523 planned floodwater retarding structures, and one dike. The 18 remaining watershed plans have completed 145 of the planned 242 floodwater retarding structures. Four of the active watersheds still have six dikes remaining to be constructed.
Watershed and Natural Resource Planning
Watershed project and natural resource activities by the Water Resources staff will follow newly established program priorities, as restricted by annual funding. Opportunities will be sought to provide project planning assistance to minorities and low-income producers in carrying out these priorities. Where projects prove to be ineligible or not feasible for PL-566 financial assistance, alternative sources of funding will be sought for project implementation.
Based on upstream flood loss data for Texas there is a real need to continue PL-566 projects for flood control and water quality.
The Texas State Soil and Water Conservation Board (TSSWCB) has been designated by the Governor as the state agency to receive and consider applications for assistance. Normally, a request for assistance is received by the TSSWCB or NRCS. A representative of the TSSWCB will be invited to participate in field reviews conducted during the pre-application phase by NRCS. Preliminary analysis is made to prepare a feasibility study. Based on the study, a decision is made to terminate assistance or develop a Natural Resource Plan or a PL-566 plan.
If the project appears to be feasible, an application for federal assistance is made through the TSSWCB. The TSSWCB sets a priority on the project. Based on this priority and NRCS current workload and funding, the project is placed on the Water Resources Staff schedule of work.
Approximately 2,000 dams in 148 watershed projects have been constructed in Texas. The programs under which these dams were constructed include PL 83-566, PL 78-534, Pilot Watershed Projects, and Resource Conservation and Development (RC&D) . A typical candidate site for rehabilitation was constructed between the late 1950's to the middle 1960's, with the majority of the dams constructed in the central part of the state, now referred to as the Interstate 35 corridor. The Interstate 35 corridor reaches from the Dallas-Fort Worth metroplex south to San Antonio. When the projects were planned the majority of this area was in a rural setting. Conversion from agricultural to urban land use has taken place and is intensifying. Many dams originally constructed as low hazard are now classified as high hazard, or will soon be high hazard as a result of downstream urbanization.
Dams are classified according to their potential to impact human lives and public infrastructure should a failure occur. Failure of a low hazard dam has the potential to cause damage to agricultural land, farm buildings, and rural roads. Failure of a significant hazard dam has the potential to damage minor state roads and utilities. Failure of a high hazard dam has the potential to cause significant damage to urban structures, main highways, and utilities, as well as potential to cause loss of life. Many high hazard dams were originally designed for a rural setting according to low hazard criteria. These dams must now be upgraded to meet high hazard criteria.
The typical dam has a drainage area of 600 to 3000 acres, a height of 25 to 40 feet, and 500 to 1500 acre-feet of detention storage. Depending on the amount and type of urban development adjacent to these dams and condition of the embankment and structural components, rehabilitation may cost from $700,000 to $2,000,000. Rehabilitation costs are shared 65 percent federal and 35 percent local watershed sponsors.
Watershed Design and Construction
Approximately 185 sites in currently approved watershed plans require design and construction. Approximately 200 structures need repair at an estimated construction cost of $44 million. About 547 dams will reach the end of their program life in 2011 and have potential need for rehabilitation. About 261 dams no longer meet current safety standards because they were designed as low or significant hazard, and are now classified high hazard because of downstream development.
Emergency Watershed Protection (EWP)
Hurricane Rita struck the Texas Gulf Coast on September 24, 2005. NRCS has completed 43 EWP recovery projects with state and local units of government and have expended over $10.2 million.
In the spring and summer of 2007, heavy rainfall resulted in flood damage in many parts of Texas. As of August 2008, $6.3 million has been authorized for EWP activities in Texas related to the 2007 floods.
Additional information on the EWP program can be found at: www.tx.nrcs.usda.gov/programs/ewp. Contact: Claude Ross, State Easement Program Manager
Operation and Maintenance
In 2000 and again in 2002, NRCS Texas asked Local Sponsoring Organizations for status reviews of Operation and Maintenance O&M for all watershed projects with dams. The reviews indicated that there is a lack of adequate O&M on about 45 percent of the dams in Texas. The main reason for the lack of O&M was the lack of funds. As of 2008, estimated funding needed to address maintenance needs is over $11 million. The local Soil and Water Conservation Districts (SWCD) , who own the easements for most of the dams, do not have taxing authority in Texas and have no funds, except those provided by co-sponsors, for O&M. Other watershed sponsors (counties, cities, water control and improvement districts) find it increasingly difficult to budget adequate funds for annual maintenance of watershed structures. Funding for expensive repairs required on aging dams is even more difficult.
Cooperative Watershed Assessments
NRCS National Headquarters originally signed an agreement with the Texas Agricultural Experiment Station (TAES) in Temple, Texas which established the Water Resources Assessment Team (WRAT). The initial purpose was to develop the computer model Soil and Water Assessment Tool (SWAT) as part of the HUMUS (Hydrologic Unit Model for the United States) Project. HUMUS analyzed effects of agricultural systems upon waters of the U.S. in conjunction with the Resource Conservation Act (RCA) appraisal.
The Texas state conservationist then established an objective to transfer this computer modeling technology to the NRCS and other end users throughout the State. The technology is jointly developed by the Texas A&M Blackland Research and Extension Center (BREC) , a unit within the Texas Agricultural Experiment Station (TAES), and the Agricultural Research Service's (ARS) Grassland, Soil and Water Research Laboratory. USDA-NRCS has helped with technology transfer, support and application of the models. The multi-agency effort allows pooling of technical resources, funding, in-kind services and orderly transfer of technology.
The effort has been underway since 1992. The staff of NRCS employees at the BREC works directly with scientists and researchers and provides feedback for model improvement. As the models are applied in small watersheds over the State, improvements are made to input and output. The WRAT also assemble or develop Geographic Information System (GIS) data required as input to the models. Models have been adapted to assess current ecosystem watershed management problems and the effects of Best Management Practices (BMPs). This process currently involves both field (or farm) and watershed (or basin) scale models such as Agricultural Policy Environmental Extender (APEX) and SWAT. The WRAT carries out this work through agreements and partnerships with local units of government.