Friday, December 18, 2015

Water Wells in North Texas


In North Texas we don't hear a lot about the ground water supply. We are mostly concerned with the surface water supply. In North Central Texas, we have one major aquifer, the Trinity Aquifer, and one minor aquifer, the Woodbine Aquifer. There are also those hand dug wells, found at old home sites, that recharge from relatively shallow ground water.


http://www.colorado.edu/
In Collin County water wells are not common, primarily due to the lack of quality ground water and the depth of drilling to access the aquifers. The aquifers decrease in depth in a southern easterly direction. Meaning the further southeast that you move through Collin County, the deeper the aquifer. Unfortunately the water from the deeper portions of the aquifer are poorer quality. The quality is poor because of the high concentrations of sodium. The high sodium concentration make the water unsuitable for irrigation. The concentrations are so high that it can kill all your plants and damage the soil. There are many wells in Collin County that are 1,000 to 1,500 feet deep and the water obtained from these wells is unsuitable for irrigation. A 1,500 foot well is very expensive to drill, and considering the lack of quality water at these depths, drilling a well in Collin County can be a risky investment. At one site it cost $60,000 to drill and case a well at 1,500 feet deep. Unfortunately the water from this well can't be used because the Sodium Absorption Ratio (SAR) had a value of 28. Depending on the crop, we generally want to see SAR values less than 10. Some salt sensitive crops may require lower values. More information can be this and other water quality standards can be found at http://soiltesting.tamu.edu/publications/B-1667.pdf
http://soiltesting.tamu.edu
If you are considering drilling a water well you need to check with your ground water conservation district for permitting and regulations. In Collin, Cooke, or Denton Counties you need to contact the North Texas Groundwater Conservation District or your county developmental services department. So if you don't have access to ground water or a water well, what are your options? A popular options has been building a pond, however some properties aren't suitable. Utilizing municipal or rural water sources is routine, but expensive for production agriculture. Rainwater harvesting can be an effective alternative if enough storage capacity can be created or installed.
http://www.twdb.texas.gov/
A recent publication from Texas A&M AgriLife Extension Service on water wells received recognition by the American Society of Agronomy. The "Well Owner's Guide to Water Supply" is a very comprehensive resource that helps well owners and others better understand the ground water supply and managing this natural resource. Download this and other publications for free at the Texas Well Owner Network website: http://twon.tamu.edu/fact-sheets/  


Other informational resources:
http://pubs.usgs.gov/circ/circ1171/html/gw_aquifer_old.htm 
http://www.colorado.edu/geography/gcraft/warmup/aquifer/aqintro.html
http://www.twdb.texas.gov/groundwater/index.asp
http://www.dallasnews.com/news/metro/20130413-study-raises-concerns-about-dallas-fort-worth-groundwater-levels-quality.ece