Low Aquifers

I attended a lecture in February and the speaker asked this question: “Why are our aquifers getting so low?” The response from the speaker and most of the audience was “Too many straws in the ground.” A few said climate change. While I cannot deny that the number of straws in the aquifer contributes to lowering of the aquifer, I doubt that this is the major reason for the aquifer’s decline.

It makes sense that more water is withdrawn from the aquifer when more water wells pump water out. If there are 100 wells in a small area, the aquifer will dip much faster than if there were 25 water wells in that same area. That assumes each pumper would extract the same amount of water per well.

But the number of straws does not take into account the volume of water withdrawn. At the family ranch in Caldwell County, the City of San Antonio is drawing water from the same aquifer just south of the ranch. They pull millions of gallons of water a day. From the same aquifer to the north, the cities of Buda and Kyle are pumping water for their citizens. There are a few large wells, but again, millions of gallons of water a day. San Antonio also pipes millions of gallons of water from Lee County across my farm in Guadalupe County.

Water withdrawal varies in different seasons. In the summer water levels drop dramatically as people water lawns and farmers water crops. When school starts the aquifer springs back up even when there is little rainfall. Last year with the fall drought, the aquifer rose very slowly. Droughts have a harsh effect on water levels in aquifers. And we will always need to deal with water shortages during drought.

Water restrictions keep water in the aquifer, but they really need to be year-round in most places. And water restrictions rarely apply to industrial sites or businesses that use water other than lawn watering and flushing toilets. However, a water company’s purpose is to sell water, so they do not want too many restrictions. In Arizona, water use per person is much less than in Texas as Arizona has more water restrictions. Higher prices for water are almost always more restrictive.

A dry spring season can have a lingering effect on aquifer levels. Since rainfall usually is less in summer months in our area, going into the summer with an aquifer that is significantly lower than average can signal problems for pumpers with shallow wells.

But with droughts aside, I believe that the real problem with declining aquifer levels is a lack of significant recharge caused by poor land management practices.

Poor ranching practices result in grass being grazed to levels so low that the cattle have trouble finding a mouth full of grasseven with adequate rainfall. This can have a greater effect on aquifer levels than the number of straws in the ground. Runoff from bare soil is greater than from tall grass.

When the aquifer does not recharge, shallow wells dry up. Deep straws continue to pump, but without recharge, those deep wells can still run out of water too. Just ask the farmers in the Ogallala Aquifer in the central U.S.

Before the industrial revolution, most springs flowed and aquifers were full. When farmers started plowing tall grass prairies and ranchers put up barbwire while overgrazing tall native grasses, the springs started drying up. Many rivers dried up too.

In areas where farmers have stopped constantly plowing and returned the land to prairie, those areas of the aquifer have risen. Even pumping water for irrigating pasture land does not cause the drop in the aquifer that pumping water for crop land does.

Further proof might be seen in the Hill Country. Where land has been stripped of grasses, recharge is much lower than the same areas where grassland exist. There is less runoff from grasslands than lands that are dominated by oaks and juniper (cedar) trees. When Dave Bamburger at Shilo Ranch in Blanco County revived the tall grasses, his springs began to flow. You can read more about Bamberger’s work at www.bambergerranch.org/ourstory.

Even in our own area, lush grasslands absorb more water than lands dominated by oak, yaupon and juniper trees. Just monitor the ditch flow next to forest and lush pastures.

While water restrictions and better management are needed, building more dams and piping water from hundreds of miles away should not be our only solutions. If Texas is going to support the largest population of all the states in 2040, we need more water. The new Texas Water Bill is designed to help, but they are barking up the wrong tree.

The State needs to work with farmers, with colleges and universities and with local conservation districts to help educate farmers, ranchers and landowners. If they learn how to grow more grass and keep the land covered at all times it will put more water in the aquifers and make the landowner more money. But will they?

I have served on water committees and have heard hundreds of ways to save water. Saving water is great, but you need to get it into the ground before you can pump it out!

It is simple to blame the number of straws in the ground rather than to put the blame on poorly managed agricultural lands. At this point, everyone in the county outside of city limits is allowed to pump all the underground water they want, but there is no one to control how they manage their land for water capture. There are some good examples of water capture, but we need more landowners do their part.

David E. Will is a local rancher and consultant. He can be reached at 830-6299876 or by email at dwill207@satx.rr.com.