22 May Searching for more water for Austin

Everyone knows that central Texas is in the middle of a drought. It’s hard to catch a news report without the mention of lake levels or to a enter a coffee shop without hearing people complaining about the dry weather. What nobody seems to quite have a handle on yet is what to do about the drought and what to do about a city that is only growing everyday,  even as its water supplies continue to dwindle. 

That is where the water resource planning task force is supposed to come in. Created by city council in order to come up with a citizen recommendation for future water sources for Austin, the task force is currently in the process of gathering all the data and information it can about the city’s options. At its meeting on Monday, the task force was briefed by an outside engineering firm about all of Austin’s supply-side strategy options for dealing with this drought and future ones. 

The engineer who presented the options was Stephen Coonan of Alan Plummer Associates. The strategy for his report, Coonan said, was not to recommend any specific option, but rather to present any and all options that he could think of, “leaving no stone unturned.” 

A few of the options Coonan presented for increasing Austin’s water supply are listed below:

-Utilizing certain types of gates at Longhorn Dam to better control how much water is released downstream 

          -No capital cost

          -Yields 2,000- 4,000 Ac-Ft/Yr 

-Reducing evaporation in Lady Bird Lake and Walter E. Long Lake (Decker Lake) by applying a biodegradable powder. By saving water in these lakes, less water has to be released from Lake Travis in order to keep Lake Austin and Lady Bird Lake at constant levels and in order to provide enough water to meet environmental flow requirements downstream. 

          -Reduces evaporation by 20 to 30 percent 

          -No capital cost

          -Yields 800 – 1,200 Ac-Ft/Yr 

-Varying the water level of Walter E. Long Lake and storing additional water there that could be used to meet requirements for environmental water releases downstream (again, preventing water from having to be released from Lake Travis). 

          -No capital cost

          -Yields 1,000 to 4,000 Ac-Ft/Yr

-Lowering Lake Austin during non-peak seasons to capture rainwater so that less water is released from lakes Travis and Buchanan to keep Lake Austin at a constant level. 

          -No capital cost

          -Yields 0 to 5,000 Ac-Ft/Yr 

-Pumping water from Lady Bird Lake back up to one of the city’s existing water treatment plants in order to capture spring flows and storm flows when they aren’t needed downstream to meet environmental flow requirements. 

          -Capital Cost- $1.8 million 

          -Yields 1,000 to 3,000 Ac-Ft/Yr

-Utilize aquifer storage and recovery (ASR), in which water can be stored underground for later use 

          -Capital cost- $130 million 

          -Yields approximately 4,000 Ac-Ft/Yr

-Utilize indirect potable reuse, in which water that has already been treated at one of Austin’s wastewater plants would be discharged into Lady Bird Lake and pumped back up to one of the city’s water treatment plants.

          -Capital cost- $30 million 

          -Yields up to 20,000 Ac-Ft/Yr

Click here for information from the latest water resource planning task force meeting.