Climate Change Crosses County Lines

Without Climate Change This map shows the anticipated risk of water shortages using traditional water-supply modeling. The predictions are based on “business-as-usual” assumptions about growth, energy and water consumption, agriculture, and so forth. Under that traditional scenario, Travis County rates high for risk of shortages.

The global-warming perils for polar bears can seem pretty remote, but a new study released last week by the Natural Resources Defense Council brings the problems created by climate change directly home to Austin. Based on the most up-to-date data, the NRDC study projects an "extreme" risk of water shortages by 2050 in Travis County. Texas emerged as one of 14 states at the most severe risk of additional water shortages and problems caused by climate change.

"The report confirms what we already know to be true in Central Texas," said James Kowis, water supply strategist for Lower Colorado River Authority. "Our water supply will decrease – and part of that will be due to climate change issues." Kowis said LCRA has incorporated similar climate-change projections in its water modeling: "Our research tells us that we'll have higher highs – and lower lows – for both temperature and precipitation. So we need to factor that variability into our planning." While there's strong scientific consensus on the rate at which temperatures will rise – useful in predicting an increase in demand – he said that projections for rainfall shifts due to global warming in the coming decades vary widely, making forecasting difficult on the supply side. For our watershed, he said, "We saw several models that we'd get more rain; others said we'd get less. We have to develop strategies that deal with either extreme."

Nationally, more than 1,100 counties – about a third of those in the continental U.S. – will face higher risks of water shortages by the middle of this century as the result of global warming, the NDRC-commissioned study found. (See the report online at www.nrdc.org/globalwarming/watersustainability.) For the first time, it offers the public a graphic, county-by-county look at the entire nation, showing where water shortages are most likely to occur. The report explores how the temperature and rainfall variations caused by greenhouse gas emissions will exacerbate the risks.

With Climate Change This map adds factors from climate-change projections. Travis, Williamson, Hays, and Blanco counties all jump into the extreme risk category; Bastrop moves up to high risk from moderate. Indeed, the majority of counties in Texas – all competing for water – are at extreme risk, with most of the remainder at high risk, only a dozen at moderate, and just a few at low.

What's the difference for Travis County between "extreme" and "high" risk? The study's Water Sustainability Index uses five criteria to rate risk. A county that meets three criteria has a high risk; meeting four or five of those criteria reflects an extreme risk. In short, the region will be using or losing more water than it gains by one additional factor. (The study details in particular the water-shortage risks for agriculture.) NRDC, a national nonprofit organization, commissioned the study from international consulting firm Tetra Tech, which used data from Intergovernmental Panel on Climate Change research and U.S. federal agencies.

"While water management and climate change adaptation plans will be essential to lessen the impacts, they cannot be expected to counter the effects of a warming climate," warns the report. "[T]he changes may simply outrun the potential for alternatives such as modifying withdrawals, increasing water use efficiency, increased water recycling, enhancing groundwater recharge, rainwater harvesting and inter-basin or inter-county transfers to make up for water deficits. The widespread nature of the risk of water shortages may also limit the effectiveness of local solutions – such as acquiring more water from a neighboring county or basin – since many other localities will be trying to get control of the same resource.

"Further, the pressure on water supplies will not cease in 2050," the report states. "If climate warming continues to increase, we can expect the risks of water shortages to increase with it. There is no way to truly manage the risks exposed by this report other than taking the steps necessary to slow down and reverse the warming trend. Doing so requires Congressional action and global leadership."

What's the average Central Texan to do – besides writing your Congressional representative to support climate action legislation? "A responsible plan for living with hotter and drier weather is to invest in efficient use of water," said Colin Clark of the Save Our Springs Alliance, which believes Austin Water should invest in repairing its leaking pipes before it builds Water Treatment Plant No. 4. "A future with more drought means summers with lower water sales as lawn-watering goes from twice a week to once a week." A true commitment to conserving water could push Austin Water into an economic crisis similar to that faced by Austin Energy, he said, leading to significant rate increases.

Greg Meszaros, director of Austin Water, suggested a good response to the climate-change study is to take the utility's 3C Challenge to commit to a 10% reduction in water use (with some help from the city's water-use calculator at www.waterwiseaustin.org). "Conservation needs to be an everyday value, not just something you do during a drought," he said. "We need that culture change." Earlier this year, City Council set a citywide goal of reducing the average person's daily water use from 170 gallons to 140 gallons by 2020.

Kowis at LCRA agreed: "Folks, we live in a part of the country where water supplies are limited, so we need to think about being more diligent in the ways we use water, as a public. Conservation, conservation, conservation!"