Industry News - Tapped: Our water trouble

Source : Lubbock Avalanche-Journal (TX)
Date : 2014-04-05
April 05 --JUSTICEBURG -- Lake Alan Henry lost roughly 4 billion gallons of water to evaporation in 2011 before the city of Lubbock took a drop.

That's twice as much as the city takes from the lake in a year.

Just four years ago, heavy summer rains flooded the lake. But that banner year was followed by the driest year on record and quickly receding water levels. Today, the city's only reservoir is a little more than 60 percent full.

Evaporation has licked up more than expected, thanks to a lingering drought and sweltering temperatures. Still more water is simply missing, according to federal government data. The water in the lake is a costly commodity for Lubbock -- more expensive than most cities throughout the state.

"I'm worried, from a scientific standpoint, about the sustainability of the reservoir," USDA soil and water management researcher David Brauer told A-J Media.

With $245 million invested in Lake Alan Henry, could the city's investment turn into a mud hole as Lake Meredith did?

"If we continue with this drought, I don't think there's any doubt," Lubbock Mayor Glen Robertson said.

"We've paid a lot of money and continue to pay a lot of money for that water.

"I don't think anybody thought we'd be here this quickly."

'We can't see the future'

Calculating the water loss is tricky because the length and width of Lake Alan Henry changes as the lake level drops. No two feet of water yield the same volume.

If the six feet lost to evaporation in 2011 were equal -- doing some quick and dirty math -- that means Lubbock lost 4.4 billion gallons of water from Lake Alan Henry. That's roughly a third of what the city uses annually from Lake Alan Henry and the Roberts and Bailey counties well fields, combined.

But that's not even the most troubling.

The U.S. Geological Survey has been monitoring evaporation, stream flow and rainfall at Lake Alan Henry as part of its mission to collect data on the nation's water resources. It's this data that worries Brauer.

"The statistic analysis shows only about half of the water is getting into the lake for storage," he said.

This finding is critical because the model city planners have used is based on storing all the water they calculated should be captured at Lake Alan Henry.

"There's a loss, or we don't have as much water running into the reservoir as we thought," Brauer said. "That's what the data suggests, one of those two things."

The amount of water being stored in Lake Alan Henry, then, is less than the amount going into the reservoir through rainfall and river inflows, and no one knows why.

City officials take a more temperate stance.

"I guess that's his opinion," Aubrey Spear , director of Lubbock City Water Resources said, noting he had not seen the federal government's data. "A lot of dynamic factors go into a lake and what it should yield.

"A lake is based on historic droughts and inflows.

"That's the best we can do. We can't see the future."

But the city's strategic plan is based on forecasting and planning for the future.

"(Lake Alan Henry) should be a renewable supply of water throughout the planning period as long as its yield does not change due to dramatic changes in the lake's environment," the city's strategic plan reads.

"Without additional water supplies by 2025, Lubbock will not be capable of supplying the projected water demand even with aggressive conservation."

'Renewable water source'

Today, the lake is at its lowest level in more than a decade.

Located 65 miles southeast of Lubbock in Garza County , Lake Alan Henry is considered one of the premier bass fishing lakes in Texas . Roughly 100,000 visitors flock to the lake annually. In 2012, gate and permit fees added $439,600 to the city's general fund.

Officials are quick to note, however, the lake's primary purpose has always been for drinking water, not recreation.

"The people that are concerned are concerned from a recreational or property owner point of view," said Robertson, who also owns a home at Lake Alan Henry.

"I understand the concern, but I have to be concerned about the taxpayers who built the lake for a water supply."

City staff began looking for an alternative water source in the '70s when Lubbock's primary water source was Lake Meredith in the Panhandle .

Once roughly 10 times the size of Alan Henry with a huge recreational draw, Lake Meredith has gradually dried up. In the wake of the city's quickly depleting water source, Lubbock leaders scrambled to accelerate its plans for Lake Alan Henry, turning on the tap in August 2012 .

About 20 percent of the city's total annual water consumption -- roughly 13.5 billion gallons in 2013 -- comes from Lake Alan Henry. It is a critical component in diversifying Lubbock's water portfolio and part of the city's 100-year plan.

If Lubbock didn't have Lake Alan Henry, if suddenly 20 percent of the city's water dried up overnight, that would likely trigger a severe water shortage and kick in Stage 2, and possibly Stage 3, of the city's drought and emergency plan.

Among the Stage 3 restrictions:

n The city would halt water-main flushes and start using, where practicable, reclaimed water;

n Landscape irrigation would be limited to one day a month;

n Outdoor watering would be forbidden for washing down hard surfaces such as vehicles, sidewalks, parking lots and gutters;

n Pools would not be able to be filled or drained and refilled.

In other words, water use in Lubbock would dramatically and quickly change.

'Protracted drought'

From its inception, city leaders have hailed Lake Alan Henry as a renewable water source.

The advantage to surface water is that it's more readily replaced with rain than groundwater. The clear disadvantage, in this arid region, is how quickly Mother Nature can lap up surface water.

At no time was that more plain than in 2011.

"The evaporation loss is pretty significant," Brauer said.

Surface area and temperature affect the rate of evaporation. The smaller the lake, the less lost to evaporation. The lower the temperature, the less lost. Of course, the opposite is true, too.

Lubbock averages 10 days a year when the mercury hits three digits. In 2011, Lubbock had 48 days of temperatures 100 degrees or higher, according to the National Weather Service .

"I don't know that anyone can plan for the five-year, protracted drought that we have," Robertson said. "It's got a tremendous watershed, but without any rain it doesn't matter how big a watershed you've got."

The lake is down about 15 feet since 2010, when heavy rains pushed the lake over the spillway and rushing across County Road 355 .

For-sale signs dot the three housing developments on the shores of Lake Alan Henry where once flooded trees now jut through the water, making it treacherous for recreational use. Private docks buckling under the blistering West Texas sun lie suspended above dry land.

"There is more risk involved with reservoirs the further west you go," said Ken Rainwater , a civil and environmental engineering professor at Texas Tech.

While Lake Alan Henry may be faring better than Lake Meredith or O.C. Fisher Dam in San Angelo -- both of which can no longer be used for drinking water -- the majority of reservoirs throughout the state are fuller, according to the Texas Water Development Board . Nearly one in five is at capacity, although those are in East Texas , which has a climate more favorable for surface water.

"The level in the lake will go down until we get rainfall," Rainwater added.

Don't look for that to happen too soon.

The U.S. Drought Monitor predicts long-term drought conditions in West Texas to persist, if not intensify through June.

For all the talk about lack of rainfall, Lake Alan Henry, 2011 notwithstanding, has been receiving rain. The lake has gotten more than 35 inches of precipitation in the past two years, according to the National Weather Service .

"Rainfall events have to be of a certain intensity and certain amounts in certain locations to produce the water," Spear said. "I still think there are a lot of different variables that Mother Nature throws at us."

'A big concern'

Because Mother Nature is often stingy with rain and the Ogallala Aquifer hasn't recharged as quickly as it's been used, securing water in parched West Texas has required big-money solutions.

Lubbock residents pay some of the highest water rates in the state. At $41 , Lubbock users pay more each month for 5,000 gallons of water than Corpus Christi and Dallas , combined.

In fact, residents pay more than anyone in the 16 municipalities used for a water bill comparison throughout the state -- 45 percent more than Austin residents, 87 percent more than in Houston , 158 percent more than Dallas and 179 percent more than folks in El Paso pay.

The reason?

It's predominantly because of the roughly $391 million in debt the water department has racked up securing and delivering water to a city that once got its water locally, but now must import it from several counties away.

And, another rate hike could be on the horizon.

Phase 2 of Lake Alan Henry is a $65.7 million infrastructure project that will expand the lake's peak capacity. That project, Spear said, could begin as early as 2017.

The USGS findings about how much water is being stored at Lake Alan Henry, however, raise serious concerns among researchers about the reservoir's viability. The science, after all, sometimes changes.

Take Lake Meredith , for example.

When construction began on Lake Meredith in 1962, the Canadian River Municipal Water Authority estimated it would yield 103,000 acre-feet a year. Later, studies found the lake was only yielding 76,000 acre-feet annually.

So, the 27,000 acre-feet difference between the two studies of Lake Meredith means the 11 cities, including Lubbock , the water authority serves lost 8.7 billion gallons of water in its annual yield because of forecasting.

Lake Alan Henry is expected to yield 22,210 acre-feet a year. The city's two-year safe yield -- meaning what the reservoir can provide in both wet and dry periods looking at the drought of record -- is 16,080 acre-feet a year. The city is conservatively withdrawing about half that.

It is unclear whether the USGS water measurements figure into the city's yield estimates, And it is uncertain whether the city's estimated yields will remain fixed or change substantively as the studies did with Lake Meredith .

What is known is Lake Alan Henry was a costly solution to the city's water woes and officials are counting on the reservoir being a viable water source, yet it may not be if attitudes and behaviors don't become more water-conscious.

"If we use it exactly the same way we used the old one, it too will disappear," Amy Hardberger , a St. Mary's University professor who teaches water law and land use in San Antonio said of Lake Alan Henry.

"Shouldn't we use it in a way that makes it more sustainable over time?"

--766-8754

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Lake Alan Henry rainfall

2013 -- 18.6 inches

2012 -- 16.45 inches

2011 -- 5.08 inches

Annual average -- about 20 inches

Source : National Weather Service

Lubbock rain

2014 -- 0.33 inches

2013 -- 12.61 inches

2012 -- 11.43 inches

2011 -- 5.86 inches

2010 -- 26.46 inches

Annual average -- 19.12 inches

Source : National Weather Service

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