What is the San Jacinto River Authority

Created by the Texas Legislature in 1937 (Article 8280-121, as amended), the San Jacinto River Authority (SJRA) is a government agency whose mission is to develop, conserve, and protect the water resources of the San Jacinto River basin.  Covering all or part of seven counties, the organization's jurisdiction includes the entire San Jacinto River watershed, excluding Harris County.  The SJRA is one of 10 major river authorities in the State of Texas, and like other river authorities, its primary purpose is to implement long-term, regional projects related to water supply and wastewater treatment.

The SJRA boundaries include the entire watershed of the San Jacinto River and its tributaries excluding Harris County. This includes all of Montgomery County and parts of Walker, Waller, San Jacinto, Grimes, and Liberty Counties. SJRA serves many customers in the Houston area and is authorized to operate in East Harris County through an agreement with the City of Houston, which allows the SJRA to operate east of the San Jacinto River.

facility locations

The SJRA’s general offices are located at Lake Conroe.  SJRA has four separate operating divisions:

Lake Conroe Division – Located at the Lake Conroe Dam, seven miles west of the City of Conroe, the Lake Conroe Division’s primary function is the operation and maintenance of the dam, spillway structure, and service outlet at Lake Conroe.  In addition, this division handles inspection and enforcement functions related to on-site sewage systems around Lake Conroe.  To maintain the safety of Lake Conroe for navigation and recreation, and to manage the construction of permanent structures on the lake, the Lake Conroe Division also administers a permit program for residential docks, piers, marinas, commercial operations, and marine sanitation facilities.  Lake Conroe was completed by the SJRA in 1973 as a water supply reservoir through a joint venture with the City of Houston, which owns two-thirds of the water rights in the reservoir.

Woodlands Division – Located in southern Montgomery County, the Woodlands Division provides wholesale water supply and wastewater treatment services to the 100,000-person community of The Woodlands Township. To provide these services, the SJRA operates three regional wastewater treatment facilities with numerous pump stations, 40 water wells, several elevated and ground storage tanks, and miles of collection and distribution lines.  The Woodlands Division serves as the wholesaler to the 12 municipal utility districts that provide retail services within The Woodlands.

Highlands Division – Located in East Harris County, the Highlands Division delivers raw water from Lake Houston through an extensive 35-mile system of canals and a 1400-acre reservoir for delivery to customers such as Exxon Mobil, Chevron Phillips Chemical Company, and a number of other industrial, municipal, and agricultural customers pursuant to long-term water supply contracts.

GRP Division – Located at the Lake Conroe Dam, the Groundwater Reduction Plan Division is responsible for implementing a countywide groundwater reduction program that will meet the requirements of the Lone Star Groundwater Conservation District and ensure reliable long-term water supplies for all of Montgomery County.  The GRP Division will seek to develop a number of alternative water strategies including conservation, reuse of treated wastewater effluent, groundwater from the Catahoula Aquifer, and surface water from Lake Conroe.  The surface water strategy will include the design, construction, operation, maintenance, and administration of a water treatment plant and transmission lines that will withdraw raw surface water from Lake Conroe, treat it to meet or exceed drinking water standards, and then transmit it to customer cities and utilities within Montgomery County.   

DID YOU KNOW?

The SJRA receives no money from the state, nor does it collect any type of taxes. Income is primarily derived from the sale and distribution of water and treatment of wastewater. This revenue covers the cost of operation and maintenance as well as outstanding debt. Revenue bonds are sold to finance projects.


There are two main types of reservoirs – water supply and flood control.  Water supply reservoirs attempt to maintain water levels as high as possible to assure the largest water supply in times of drought. Flood control reservoirs maintain water at a low level so that when a storm comes, water may be detained and stored to decrease or eliminate the threat of flooding downstream from the reservoir.

Lake Houston, Lake Conroe, and Lake Livingston are water supply reservoirs. Addicks and Barker Reservoirs are flood control reservoirs. Some reservoirs, like Canyon Lake, have both water supply storage and flood water storage.

types of reservoirs 

*Safety Freeboard is the  area between the water surface and top of the dam, large enough to prevent waves from overtopping the dam.