Drinking Water

Source

In 2000, the City of Houston drew 67 percent of its drinking water from its four surface-water treatment plants. Surface water comes from the San Jacinto River through Lake Houston and Lake Conroe, and from the Trinity River through Lake Livingston. Thirty-three percent of Houston’s drinking water is acquired through 197 wells at 97 groundwater treatment plants that draw from the Evangeline and Chicot Aquifers.[i]

Subsidence

Over-reliance on groundwater in the region has caused subsidence, or the irreversible sinking of the ground surface caused by the withdrawal of a fluid, such as water or oil. Water levels in the Chicot and Evangeline aquifers had lowered by as much as 400 feet by 1973, causing up to nine feet of subsidence in parts of Harris County. Almost all of the county has subsided at least one foot; subsidence in coastal areas ranges from six feet in Texas City to nine feet in Baytown. Subsidence rates in Galveston County and eastern Harris County have slowed dramatically over the last few years because of efforts to reduce reliance on groundwater. North and west Harris County – which lack an alternative water supply – have experienced the most subsidence recently.[ii] 

Subsidence causes loss of coastal habitat and increases flooding. To combat subsidence, the Harris-Galveston Coastal Subsidence District, created in 1975 by the Texas Legislature, regulates groundwater pumping in the region. Its overall goal is to convert groundwater systems to surface water systems. The City of Houston plans to convert to at least 80 percent surface water by 2030.

In areas in Texas where a subsidence or groundwater district does not exist, groundwater is controlled by the “rule of capture,” a controversial law that allows landowners almost limitless pumping from below their property. Problems arise when landowners deplete aquifers that supply both them and their neighbors. 

Quality

All community water systems in Texas are required to provide customers with an annual report on the quality of their drinking water. Drinking water provided by the City of Houston regularly meets or exceeds Texas Natural Resource Conservation Commission (TNRCC) and Environmental Protection Agency (EPA) water quality requirements. The 2000 Water Quality Report for the Houston area can be acquired by calling the City of Houston at (713) 837-0600 or visiting www.ci.houston.tx.us/pwe/utilities/waterprod.htm. Water quality outside the city varies by source; reports for outlying areas are available by contacting the local Municipal Utility District.

More information about water contaminants and their potential health affects is available by calling the EPA’s water quality hotline at 1-800-426-4791.

Water Planning

Experts estimate that Texas’ population will double to more that 40 million over the next 50 years. Meeting the demands of all these new water users while maintaining adequate flows for sustainable ecosystems will be a tremendous challenge. In 1997, the Texas legislature passed a bill that required individual regions to prepare plans that map out how water demands through 2050 will be met. The Texas Water Development Board (TWDB) then evaluated and modified the regional plans, and melded them into a State Water Plan.

Region H’s plan, which covers 15 counties in the Houston area, recommends that three new reservoirs be built on the Brazos and Trinity rivers in the coming decades. Some environmentalists believe the new reservoirs will destroy wildlife habitat and alter ecosystems; they would prefer the region rely more heavily on conservation measures. There is also some concern that the plan would reduce freshwater inflow into the bays.

The Texas State Water Plan, approved by TWDP in December 2001, recommends building a total of eight reservoirs at a cost of about $17.9 billion. Many are concerned that the plan emphasizes financially irresponsible construction projects over conservation and does not account for the water needs of fish and other wildlife. Incidentally, the Region H Plan is the only regional plan that apportions at least some water for ecosystem needs.

The plan is to serve as a blueprint for future state water policy and does not include funding for specific projects. However, in November 2001, voters approved a state constitutional amendment that allows the water development board to issue up to $2 billion in general obligation bonds for water, wastewater, and flood control projects.

What You Can Do

Conserve water

Install low-flow shower heads and toilets. Fix leaks. Turn the water off while you brush your teeth and shave. Run the dishwasher and washing machine only for full loads. Water your lawn only when it needs it. Xeriscape.

Protect water quality

Reduce your contribution to non-point source pollution.

Stencil your storm drains

Storm-drain stencils that say “You Dump It You Drink It” are available from the City of Houston Household Hazardous Waste Program at (713) 247-8589.