Needs Surveys

Clean Watershed Needs Survey

The Clean Watersheds Needs Survey (CWNS) was mandated by the Clean Water Act (Act), passed by Congress and signed into law in 1972. The survey measures the need for public entities to build capital infrastructure to meet the water quality and public health goals of the Act. Infrastructure includes wastewater collection systems, conveyance lines, lift stations, treatment plants, effluent disposal systems, solids processing, storm water pollution control facilities, and water recycling and reuse systems.

The survey is conducted by EPA Headquarters in four year intervals with participation by states and EPA's ten regions. Estimated needs are tabulated by state and reported to Congress. Congress has used CWNS results to develop or amend the Clean Water SRF allotment formula - used to distribute federal State Revolving Fund (SRF) program capitalization grant funds among all the states - each time the Act has been reauthorized, in 1977, 1981, and 1987. There have been numerous unsuccessful attempts to change the allotment formula since.

The CWNS allows a census of publicly owned treatment works (POTWs) - usually referred to as wastewater "facilities" - as defined by Section 212 of the Act. There are more than 2,900 existing or potentially needed facilities in Texas. TWDB staff members collect information and documentation about all of them, with special emphasis on larger utilities. The most recent CWNS was completed in December of 2012. Preparations for the next CWNS will begin sometime in 2014.

Drinking Water Infrastructure Needs Survey

The Drinking Water Infrastructure Needs Survey (DWINS) was mandated by the Safe Drinking Water Act (SDWA) Amendments of 1996. The survey measures the need for public water systems to build capital infrastructure for a 20-year period. This includes wells, intakes, treatment plants, transmission lines, storage tanks, pumping facilities, and distribution networks.

The survey is conducted by EPA Headquarters in four year intervals with participation by states and EPA's ten regions. Estimated needs are tabulated by state and reported to Congress. The SDWA requires EPA to use the results of the DWINS to develop a formula to allot federal funding to the states for the Drinking Water SRF program for the ensuing four years. The DWINS uses a stratified sample of public water systems. There are three strata: large (systems serving more than 100,000), medium (3,301 to 100,000), and small (3,300 or fewer). The sample in each state includes all large systems, a statistical sample of medium systems, and no small systems - the estimated needs for small systems are based on a national sample and apportioned to the states according to the number of systems in each state. The most recent DWINS in 2011 sampled 144 out of 1,020 large and medium systems in Texas, and included roughly 60% of the state's retail water service population.

In every DWINS (1995, 1999, 2003, 2007 and 2011), TWDB has partnered with the Texas Commission on Environmental Quality (TCEQ) and its contractor, the Texas Rural Water Association (TRWA), to contact surveyed systems and collect information. Water systems are studied intensely to identify needed works - the rehabilitation, replacement or improvement of specific assets. During the 2011 DWINS, TWDB submitted nearly 8,000 projects with associated documentation for the 144 surveyed systems.