Like many water agencies, the El Dorado County Water Agency in California started looking into climate change five years ago. More than just the natural variations in climate was happening, with less rain falling and less snowpack melting into the American River near Sacramento.
That worried Bill Hetland, general manager of the water agency. With snow melting earlier in the spring, it meant more runoff and a need for more long-term storage. Two years ago, they came up with a drought plan.
“We’re going to be in a world of hurt” without more storage, Hetland said. So the water agency started working with area utilities to add storage. It now has 15,000 acre-feet of storage specifically for drought protection.
El Dorado is just one of many agencies throughout the United States dealing with climate change and its effects on preparation for floods and droughts. Local and state governments, utilities and water agencies are preparing for these changes faster than they might have liked, though.
According to a climate change analysis prepared for the El Dorado Irrigation District, average temperatures during the next 100 years will increase about two degrees Celsius. Higher temperatures will result in heavier snow runoff earlier in the season, and future droughts are expected to be longer and more intense.
Other effects of climate change include rising sea levels, more variable runoff patterns, increasing or decreasing rainfall, shorter snowfall season as spring snowmelt begins earlier, changes in water quality, increased evaporation and a shifting jet stream.
Climate change is causing less rain in the United States, but when it does rain it will be an intense “gully washer” that could cause floods, said Gerald Galloway, a retired brigadier general with the U.S. Army and an engineering professor at the University of Maryland.
“It’s the intensity that’s going to be the issue for flooding,” Galloway said, adding that climate change has a direct relationship. “When you talk about hazards for the country, climate change is going to exacerbate it,” he said.
If nothing else, climate change is forcing more agencies to work together to share supplies and to do more long-term planning, said Melanie Holton, a principal engineer for Brown and Caldwell in Sacramento.
“You always think ahead as far as your infrastructure needs … But now (agencies) are thinking ahead as far as sustainable applications,” Holton said. “It’s forcing our clients that rely on surface water to plan for the dry years” by tapping into groundwater.”
Having less rain has caused the many jurisdictions that pull water from the Colorado River to cooperate, said Rick Holmes, director of environmental resources at the Southern Nevada Water Authority. Of those states that draw water from the Colorado River, Nevada uses the least at 2 percent, or about 300,000 acre-feet a year, Holmes said.
SNWA’s conservation efforts are working so well — water consumption declined by about 20 billion gallons from 2002 to 2008 — that it recently gave some of its Colorado River allocation to parched California in exchange for a future giveback when Southern Nevada needs it.
“We all work together,” Holmes said, “because if there is a shortage, a drought, a stress on the system, it’s easier to spread that around.”
San Diego, which imports up to 90 percent of its water, is trying to get ahead of the curve by having Brown and Caldwell write up a white paper on the effects of climate change.
“Everyone knows that this (climate change) is happening, but because we’re really not too far down the road, nobody really knows what the impacts are going to be,” said Marsi Steirer, deputy director of the City of San Diego Water Department.
Although computer models can help make recommendations if an area is in a drought, many regions are already seeing extremes, said Paul Selsky, a senior water resources engineer at Brown and Caldwell in Sacramento. “It makes the problems of droughts even more severe,” Selsky said of increasing global temperatures.
The American River in California, for example, is higher in March and April, instead of May, because the snow is melting earlier, Selsky said. This, in turn, causes storage problems for agencies such as the El Dorado County Water Agency, which now has deals with Sacramento and the Sacramento Municipal Utility District to use five reservoirs and hydroelectric plants for water storage. It adds up to about a $100 million worth of reservoir capacity, Hetland said.
El Dorado also is negotiating with power plants to get more storage and credit to use at a later time. For now the agreement doesn’t include water rights, although El Dorado is applying to get water rights from SMUD. “Even though they gave us the storage, we have no water to put in the storage,” Hetland said.
The Lower Colorado River Authority is a Texas conservation and reclamation district that is revising its strategic water supply planning document to determine if more and diverse sources of water supply are needed. Possibilities include using surface and groundwater, additional “scalping” reservoirs to take advantage of any excess flows, and desalination.
LCRA is working with its rice farmers on water conservation strategies, such as land laser leveling and new rice varieties that produce the same or more amount of rice using less water.
But uncertainty seems to be one of the biggest worries for water agencies and utilities, said Jim Harper, a water resources supervising engineer for Brown and Caldwell in Portland.
“They’re not sure what’s going on and what impact climate change is going to have on their systems,” Harper said. “They think there’s going to be more flooding, more drought.”
Oregon doesn’t have a comprehensive water resource plan, but is working on one, he said. Southern Oregon is in a three-year drought, and agencies are seeking aquifer storage as well as ways to get more reservoir storage.
Wells in the Hermiston area in Oregon have dropped 500 feet, which is causing water officials to look at pumping water from the Columbia River in the winter to recharge aquifers, Harper said. Climate change, he said, is forcing people in usually wet Oregon to think more about long-term planning.
The El Dorado Irrigation District has a drought preparedness plan and is working on a climate change model, said Liz Mansfield, water resources division manager. District officials decided to study climate change more after wrapping up their drought plan in 2007, Mansfield said, adding that planning in the water industry is something that needs to be done more. “We don’t plan enough for climate variability, regardless of climate change,” she said.
Her district also is starting to look at customers’ behavior and economic triggers to find out what people are willing to pay for more reliability.
Another challenge is getting customers to use less water in a drought even as their rates increase. Paying more for less can be a difficult pill to swallow. Water conservation is working so well in north Georgia, for example, that a 30 percent reduction in water use has led to a 30 percent decrease in revenue for some water agencies, requiring an increase in rates.
Residents in DeKalb County, Georgia, must prove they are low-water users under an ordinance that requires anyone who buys a home to show it has been retrofitted for low-flow fixtures, such as shower heads and kitchen faucets. The mandatory program started in June 2008, six months after an optional program began giving rebates for replacing toilets that use less water. Last year, 5,681 toilets were replaced through the program, said Curliss Rogers, a spokeswoman for the county.
The Southern Nevada Water Authority has been in a severe drought since 2000 and has taken many steps to encourage its users to conserve water. One of its most successful moves has been its “Water Smart Landscape Program,” in which customers are paid $1.50 for each square foot of turf they remove and replace with water-efficient landscaping. Since the program started in 1999, the agency has converted more than 125 million square feet of turf, or enough to lay a strip of sod two-thirds of the way around the Earth. A square foot of grass saves 55 gallons of water a year, SNWA’s Holmes said.
Other SNWA incentives include rebates for pool covers to reduce evaporation, rebates for replacing irrigation clocks with more efficient controllers that interrupt irrigation during and after significant rainfall, rebates for high-efficiency washing machines, and fixture replacements.
Although it’s an exciting place to work, Holmes says climate change has made his job more challenging. The agency gets 90 percent of its water from the Colorado River, which has always had a wide range of flows. But since 2000, the state has been in a severe drought that has changed how SNWA does business. Inflows to Lake Powell in Nevada are 62 percent of normal during the past eight years, and last year Southern Nevada received just two inches of rain, half of what it typically gets, Holmes said.
"We look at climate change … all models are pointing in a negative direction for stream flow in the Colorado River,” he said.
Climate change is causing some agencies, such as the South Florida Water Management District, to rethink how it fulfills its mission of providing a water supply and flood protection. The district is investigating what to do as sea levels rise, and already has canals, rivers, control structures and wetlands to move and store runoff from rainfall to help minimize flooding.
“In many cases, we’re not planning for change, we’re experiencing it,” said Chip Merriam, deputy executive director of water resources for the district, which manages and protects water resources for 7.5 million South Floridians.
Everglades restoration — the largest environmental project in the nation’s history — wasn’t originally thought of as a way to combat the effects of climate change, but it may turn out that way as it keeps seawater from moving inland. Along with rising sea levels, significant rainfall during high tides, with a strong wind, can push more seawater inland and affect salinity levels in groundwater.“A lot of what we do in South Florida is staving off the Atlantic Ocean,” Merriam said.
Hurricane Katrina was the biggest test of America’s levees so far, but a big part of this problem is that levees aren’t built to high enough standards, said Galloway, a flood expert.
Floods in Louisiana and Mississippi spilled over levees built to a 100-year standard, meaning there is a 1 percent chance in any given year that a flood will rise above the levee. That’s OK for farmland, but not urban areas, Galloway said.
In the Netherlands, inland levees are built at a 2,000-year standard, and levees for ocean flooding are built for a 10,000-year standard, although Dutch officials have called for a 100,000-year standard on the coasts, Galloway said. New Orleans is being rebuilt to a 100-year standard, which qualifies property owners for the National Flood Insurance Program.
Repairing or building higher levees is at the top of the list of ways to prevent flooding because the risk is so high, Galloway said, but other things that can be done include elevating homes, preparing evacuation routes and providing early warning of flooding to residents. Bigger solutions include building dams upstream to hold more water and restoring wetlands to protect the coast.
Agencies and cities must balance the cost of building a high levee against the cost of what that levee is protecting, Galloway said. “You’ll never be able to completely protect a flood plain. That’s just plain fact,” he said.
Even though a Hurricane Katrina won’t hit California — the Sacramento and San Joaquin rivers are inland and thousands of miles from the nation’s hurricane zone — experts say the area’s floodplains are in line to be the next New Orleans. Much of Sacramento is below the levees that protect the city, and the Sacramento Bee has reported that more than 300,000 people would be in the direct path of a flood.
In Texas, where flash floods are common, the San Antonio Water System is in a “flash flood alley” that is in a drought but experiences intense rain and flooding, said Kelley Neumann, vice president of engineering at SAWS.
Although it’s not clear whether climate change is causing more severe droughts or floods in San Antonio, Neumann said the water agency has learned that an aquifer storage and recovery system it opened in 2004 to hold 25 percent of the city’s water is being used in unexpected ways.
The $250 billion underground reservoir was meant to capture and store floodwater that would be used each summer, emptying the reservoir. But severe droughts have changed the agency’s thinking. Water restrictions have been so successful, Neumann said, that instead of using the water each summer, it is saved for big droughts.
“It’s all a crapshoot,” Galloway said. because flood planning for hurricanes and rising sea levels is difficult using 100-year plans. “We’re building structures for today’s conditions when today’s conditions are going to be out of date tomorrow when they’re built,” he said.
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