Thursday, September 8, 2016

Water - Waste Not, Want Not - Unless the Well Runs Dry

For most if not all of my readers I suspect filling a glass of water is an easy task. Flip a lever or turn a handle and fresh water rushes out to fill a waiting receptacle or it continues rushing down the drain. But do you ever stop and think where your water comes from or how resilient your water supply is? For about half of all Americans at least some of their water comes from ground water, while that number gets pretty close to 100% if you live in a rural area. The other source of water is surface water, often from large reservoir lakes. Recent droughts in Georgia and in Texas made national headlines when some cities that relied on lakes for their drinking water came very close to running out of water. Imagine that, flip the lever or turn the handle and nothing comes out. What a nightmare scenario. Thankfully for Atlanta and Wichita Falls, the rains returned before that happened and recharged their surface reservoirs.

It is pretty easy to see how a town that relies on water from lakes can recover pretty quickly if there is drought breaking rain. But what happens in areas that depend on aquifers, ground water, to quench thirst and water gardens? A lot of that depends on the characteristics of the aquifer that water is being pumped from. In some areas surface water becomes ground water quickly and easily because the material between the soil's surface and the aquifer is very permeable. In other areas the recharge zone for an aquifer can be far away because of the tilt of the water bearing sediment or rock layer. In Austin, rain water percolates downward through limestone to reach the Edwards aquifer. Many people in DFW that use well water drill into the Trinity aquifer. The recharge zone, outcrop, for these wells is about a county or two west of their well location.

Distance from the recharge zone, permeability of the sediments between surface water as lakes, streams or storm runoff and the water bearing layer that creates an aquifer as well as precipitation play a big role in how quickly an aquifer can recharge. It is very important to get a handle on this relationship where ground water is the source or even part of the source of water for a given population. Unfortunately, extensive farming centers are currently tapping portions of a giant aquifer that have little (very slow) or no recharge. This is what is happening to the Ogallala aquifer that stretches from the panhandle of Texas through the panhandle of Oklahoma, western Kansas, most of Nebraska and portions of New Mexico, Colorado, Wyoming and South Dakota. It is the portion of the Ogallala in Texas, New Mexico, Oklahoma and Kansas where water is being used for farming and people faster than it can recharge.

This massive over pumping of the Ogallala has the potential of creating a manmade disaster in the area much like the plowing that contributed to the disastrous dust bowl era, "The irrigation era may come to be called the "great pump up," bookending the other manmade High Plains disaster—the "great plow-up."" Large areas of the Ogallala are headed towards permanent depletion in our lifetime if something is not done to curb the draining of the aquifer. Residents just south of Clovis, New Mexico are already experiencing this. An example is given near the bottom of the article linked above.

So what can you do? Even if you are in an area that does not experience periodic drought or does not get your water from an aquifer that is in decline, conserving water is something everyone should be doing. Planting native or adapted plants for your area allows you to conserve water because they will not require much or even any supplemental watering. If you still have older, heavy water using toilets and shower heads you can replace them with the low water using ones currently on the market. Don't let the water run while you are brushing your teeth. These are just a few of small and large changes that you can make so that hopefully you won't see the day when you flip a lever or turn a handle and no water comes out of your faucet.

1 comment:

  1. Thanks for an important article. Appreciating our water and the easy access we have is a good reminder.