The POSGCD Board of Directors held their regular monthly meeting May 11, 2020. Dr. Brad Wilcox from the Department of Ecology and Conservation Biology at Texas A&M University gave a presentation on the potential for enhancing recharge in the Carrizo Wilcox Aquifer. The presentation entitled “Potential for Increasing Recharge in the Post Oak Savannah Ecoregion” outlined a study Dr. Wilcox and PhD student Shishir Basant have been working on in Burleson County. They were studying the effect of brush clearing to increase the potential for increasing recharge by restoring the and to true savannahs would increase the amount of recharge to the aquifer.
The Board of Directors funded a grant of $30,000 to study the differences in recharge amounts in the different types of land cover. The study took place on property that belongs to the King family in the eastern part of Burleson County. Studies have shown the intensive change in the landscape in Texas from rangelands to forested areas and shrub lands. This change aligns exactly with the Carrizo Wilcox aquifer. This change is due to several factors including; new farming practices, less fires that would reduce the brush and other factors have cause the landcover to change from a true savannah with rangelands to thicketized woodland with post oak, yaupon and eastern red cedar.
By managing vegetation to increase groundwater recharge, Dr. Wilcox suggested that this part of the state has the most opportunity to increase. Some of the reason our area prime to help in this situation is the amount of rainfall in our area, the porosity of the sands in the aquifer and the amount of brushy areas verses the savannah areas. Trees and woody areas pump a lot of rainwater from the ground through transpiration keeping that water from reaching the aquifer, recharging the aquifer thus changing the water cycle.
By using specialized moisture measuring tools, taking core samples and measuring the amount of chloride in different depths in the soil we can measure the recharge rates. The chloride inputs from the atmosphere gets absorbed into the soil. By measuring the amount or chlorid at different depths and comparing these trace minerals from the pasture’s areas and the woodlands, we can see the amount of water moving through the soil. These studies show that the amount of recharge is as much as 100 time greater in the pastures than in the woodlands.
These studies could lead to grants given to local landowners to reduce the woodlands and restoring the area back to true savannahs to increase the recharge to our aquifers. To see the entire program, go to www.vvimeo.com/5484736929 or our website www.posgcd.org/agendas-minutes/posgcd-agendas-minutes/