Eileen Berger Indian Trail Master Naturalist
Last summer’s heat and drought can seem like a bad dream when it is 40 degrees on a rainy day in a series of rainy days. However, it did happen, and although we in north Texas have had good rainfall this winter, many of our Texas neighbors to the south and west have not. The old saying “You don’t miss the water until the well runs dry” is still timely today if you substitute the words “lake” or “river”.
Texas is a big state, both in area and population. The population in 2000 was 21,000,000 people. It is projected to increase to 46,000,000 people by 2060. Each one of those people will expect to have access to clean water in abundance. Unfortunately, that may not be possible, because based on current sources, only 65% of the needed water will be available.
When early settlers came to Texas, they found cheap land and plentiful sources of water. Texas has numerous rivers, streams and springs. Those, along with man-made ponds and reservoirs, constitute what is called surface water. Our surface water is replenished by runoff and accumulation of rainfall. Since we do not have regular snowfall, we do not get much accumulation from snowmelt, as do states like Colorado. Not only do we have this surface water, we also have underground aquifers which supply what is called ground water. Aquifers are geological formations which contain water. Texas has several aquifers which have been tapped by wells to supply water to farmers, ranchers, towns and cities. The aquifers across Texas have been depleted by both farmers for irrigation, and municipalities for use by citizens. The Edwards aquifer, which supplies Austin and San Antonio, has been in the news lately because of the failure of the aquifer to recharge itself due to overuse and a lack of rain.
The water in these aquifers has taken hundreds of years to accumulate naturally. When rain falls, some of it runs off the surface of the land and collects in streams and rivers, which eventually flow to the oceans. The part that doesn’t run off may percolate down through the soil and porous rock beneath and collect in aquifers. If only a small amount is taken out of the aquifer, then the level will remain balanced. Explosive growth has taken place in Texas along Interstates 35 and 45 in the last 50 years. For too long, some of the cities and towns have relied on the aquifer to supply water.
The only naturally-occurring lake in Texas is Caddo Lake. During the early part of the 1900’s, water authorities began damming Texas’ rivers to form reservoirs to supply water to the citizens of Texas. This surface water relies on runoff from rainfall to fill the lake, and have enough excess to allow the river to continue its flow to the sea. If we have several years of low rainfall, or even worse, the drought combined with extreme heat, then the lake levels drop. Failure to release water from the reservoir into the river would lead to catastrophe for the river and the animals and plants that depend on it, as well as the humans who may need it for drinking water, irrigation of crops, and recreation.
Articles in the coming weeks will continue the discussion of water facts as well as some tough choices that will need to be made by Texans.