Published: May 07, 2008 05:40 pm            

Water: What do we do now?

With the almost unprecedented summer rainfall that this area enjoyed in 2007, it is easy to forget 2006 and the other end of the spectrum. However, all we need to do is look east of us and west of us to remember that drought and water problems can be back here at any time in the future if we are not prepared.

Water supplies are primarily about storage, and long-term water storage is practical only in surface reservoirs (lakes) and subsurface reservoirs (aquifers).

In 2005, the City of Ada initiated a contract with C. H. Guernsey Consultants to investigate the feasibility of Scissortail Reservoir, which would be located about one and one-half mile west of Ada. Guernsey has provided two reports and is currently working on a final report that will summarize findings. The initial reports estimate that Scissortail Lake would cost Ada approximately $180 million, and could be funded over a 30-year period with a one-penny sales tax plus a two-to three-fold increase in water rates.

In the fall of 2007, The City of Ada employed a four-member technical review panel to review the Phase II feasibility report. The Panel included three retired engineers with over 60 years of direct experience with the U.S. Army Corps of Engineers in the construction of dozens of major reservoirs. The consensus of the Review Panel was that nothing in the Phase II report precluded the technical feasibility of Scissortail Lake, but several items will need further investigation to confirm the technical feasibility and to reduce the extreme uncertainty in cost estimates. The most significant questions relate to the availability of adequate clay soils suitable for the earthen dam and raising the Highway 19 roadway and the cost of mitigating unstable geologic strata beneath the dam.

The source of Byrd’s Mill Spring, the Arbuckle-Simpson Aquifer, has a massive amount of fresh water in storage. However, as is true with surface reservoirs, the amount that can be pumped from the Arbuckle-Simpson on a continuous basis and maintain it as a sustainable resource, is limited by the rate of recharge. Oklahoma’s water law currently allows for temporary permits up to two acre-feet of ground water per surface acre of owned or leased land. Recharge to the Arbuckle is estimated at about one-fifth of that number.

The Oklahoma Water Resources Board is in the final year of a five-year hydrology study of the Arbuckle-Simpson to determine how much ground water can be pumped on a continuous basis and still protect the springs and streams of the area. This study is required by Senate Bill 288 passed by the Oklahoma Legislature in 2003 and is critical to protecting Byrd’s Mill Spring, Ada’s water supply for almost 100 years.

Ada currently uses a yearly average of about six million gallons of water per day (MGD). Daily use sometimes peaks at over 10 MGD on some hot summer days. According to the Scissortail feasibility report, average use is projected to double by 2050. Average flow from Byrd’s Mill Spring is about 10 MGD, but varies with rainfall patterns from less than 3 MGD to more than 20 MGD. Ada also has about 10,000 acres of ground water rights and potential temporary ground water permits for over 16 MGD. It is true that results of the current OWRB study will be that those 10,000 acres of water rights will be worth much less than 16 MGD in permanent ground water permits. However, there are many landowners over the Arbuckle-Simpson with many thousands of acres of ground water rights for sale. Landowners can, and some want to, sell their ground water rights because they still retain the right to use all the water that they need for domestic uses and livestock watering.

Ada’s current primary water supply is stream water (Byrd’s Mill Spring). Ground water is used only when flow from Byrd’s Mill Spring is inadequate due to extended periods of dry weather. Of course, those periods of pumping ground water will increase as Ada grows and water use increases.

There is the potential to increase recharge to the Arbuckle-Simpson and possibly the flow of Byrd’s Mill Spring through artificial processes that are employed in many locations throughout the world. Estimates are that less than five inches of the area’s approximately 40 inches of annual rainfall actually infiltrates and recharges the aquifer. If recharge to the eastern part of the Arbuckle-Simpson could be increased one inch per year, it would make over 16 MGD in additional water available for spring flows and/or pumping. Senator Susan Paddack has sponsored legislation that will establish pilot enhanced recharge projects for four Oklahoma aquifers. One of those projects will be over the Arbuckle-Simpson Aquifer.

A common misconception in Ada is that Byrd’s Mill Spring and the Arbuckle-Simpson Aquifer are somehow unreliable as a long-term water supply. Some of that uncertainty results from real, unresolved legal and permitting issues and some results from rumors and myths.

The City of Ada will be having a “town hall meeting” on water on June 18, 2008 at Pontotoc Technology Center to discuss the results of the Scissortail feasibility study and the options facing the citizens of this area in assuring a water supply for the long-term future.

Whatever options are selected, it is likely to cost users more for their water. I urge all citizens to watch for that announcement, attend the meeting to get the facts, and to express their opinions.

        

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