It was in the early 1900’s that the Houston area began to see the first true signs of human-induced land subsidence — initially attributed to the extraction of oil and gas from beneath the surface, and relegated to the land immediately in and around the center of the oil fields. But the future would hold a much more widespread and insidious cause for subsidence in our area – expanding industry and a growing population’s water needs.
Houston was growing and it was growing fast. Increased oil production and the establishment of the Port of Houston in 1925 were creating an industrial and population “boom”. The area’s plentiful supply of fresh groundwater helped to fuel the massive growth, but ultimately, the community’s need outpaced the aquifer’s ability to safely sustain their demand for water.
In the early 1940’s, new studies began to identify problems due to groundwater extraction. Original land-subsidence benchmarks, established just after the turn of the century, were releveled in the 40’s, and the results verified that subsidence was occurring.
In the 1950’s and 1960’s, community leaders finally began to link the increased frequency and severity of flooding to subsidence. In the sub-tropical, low-lying areas of Houston/Galveston — where tropical storms and hurricanes were a probability, not just a possibility– flooding was real and could be severe. In 1961, when Hurricane Carla hit, our worst fears about the impact of subsidence were confirmed. The storm had been horrific and some water damage was not surprising, but the flooding that occurred was beyond what was, in the past, expected from a hurricane of this size. As a result, local area governments began to analyze the serious and very real impact subsidence could have on the area’s potential economic growth and quality of life, and, just as important, began to determine what exactly could be done about it.
With a number of studies linking groundwater withdrawal to subsidence — and ongoing measurements confirming those findings — groups of citizens began to work for a reduction in groundwater use in the late 1960’s. By 1973, the City of Galveston had begun converting to surface water supplied from Lake Houston, and in May of 1975, the Texas Legislature created the Harris-Galveston Subsidence District (HGSD), the first of its kind in the United States. Authorized as a regulatory agency created to “end subsidence” and armed with the power to restrict groundwater withdrawals, the Subsidence District immediately went to work on a plan to positively impact the critical situation in the coastal areas.
By 1976, the District had begun the process of compiling hydrologic information on the characteristics of the Chicot and Evangeline aquifers, engineering planning information on water usage and water supply in Harris and Galveston counties, and implementing regulatory procedures associated with their first groundwater regulatory plan. By converting industries on the Houston Ship Channel to surface water supplied from the recently completed Lake Livingston reservoir, subsidence in the Baytown-Pasadena area was dramatically improved, and has since been largely halted.
But as subsidence was stabilizing in the coastal areas, groundwater levels in inland areas north and west of Houston were rapidly declining. In the Evangeline aquifer, measurements recorded a decline of more than 100 feet between 1977 and 1997.
As a result of the increasing threat subsidence posed to these areas, the HGSD adopted a series of regulatory plans to reduce groundwater pumpage, and ultimately mandated, in their 1999 plan, a reduction to only 20% reliance on groundwater by 2030. With the help of the North Harris County Regional Water Authority (NHCRWA) and the West Harris County Regional Water Authority (WHCRWA), both created by the Texas Legislature to transition the areas to surface water in the allotted timeframe, a fair and equitable contract with the City of Houston to supply surface water from Lake Houston was successfully negotiated and construction is already underway in both Authority areas. It is our goal that the same dramatic improvements will occur in these areas as were experienced south and east of Houston years ago.
The HGSD, along with numerous utility districts and other public and private partners, have also worked hard to educate the public on water conservation, for one very simple reason: The future of our water supply not only depends on where we get it, but on how EFFICIENTLY we are able to use it. (Please take a moment to go through our web site and read about our highly successful WaterWise program).
Water is an element that has no substitute, and our need for it will always be there. The population in our area will only continue to grow, and our need for water will grow right along with it. It is the responsibility of the HGSD — as well as those of us fortunate enough to live in this wonderful area — to treat our precious natural resources as the treasures they are– not only for us, but for those who will be here long after us. This is a responsibility we take very seriously and we appreciate your interest and support in achieving this goal.