Monday, June 28, 2010

Wichita water supply lines are at their limit Read more:

Wichita water supply lines are at their limit


The Wichita Eagle


If Wichita were to enter a drought this summer, it couldn't provide enough water for all the thirsty plants, dirty cars and loads of laundry out there.
The city is permitted to draw 240 million gallons of water a day from Cheney Reservoir and a local well field, which is plenty.
But its aging and underdeveloped infrastructure can process and deliver only a bit more than half of that — 130 million gallons a day.
That's not enough to meet demands of the city in a long, dry summer, much less during a prolonged drought.
"If a drought were to start right now, we've got the water rights to handle it with the population we have in Wichita," said Deb Ary, Wichita's superintendent of production and pumping. "We don't really have the infrastructure to handle it safely."
Wichita has had several years of wet weather — including the record-breaking 53.8 inches of rain in 2008. Climatologists say drought is nearly impossible to predict, but that from a historical perspective, Wichita is due.
"Historically, we have had patterns of wet and dry and they tend to run on a 20-year cycle," said state climatologist Mary Knapp. "We've had our wet period and we've had our dry period. So the question is, do you want to have the expectation that you'll continue in a wet pattern when you have historical evidence you'll have a dry pattern?"
Wichita also has to worry about those hot summer days when the city often has its peak demand for water.
A recent study by the city's water consultant, HDR Engineering Inc., found that the city is 4 million gallons a day short of being able to supply local water customers on the highest water use day of the year.
And by 2041, the city won't have enough water for even average days.
If the city thinks it is close to running short, it would likely ask people to voluntarily use less water. If that doesn't work, it would likely impose mandatory restrictions.
The potential for shortage highlights a complicated and frustrating dynamic as Wichita hikes its water rates, effective Thursday:
People are using less water, but the price of water will probably continue to rise.
Supply and demand
Wichita once drew most of its water from the Bentley and Equus Beds well fields north of the city.
But in 1993 it began using Cheney Reservoir more because it had drawn down groundwater levels in its well field.
The aquifer recharges during a rain. But the city was pumping water out faster than nature could put it back in through rains.
That created another problem.
A salty plume of groundwater caused by oil exploration is slowly moving toward the Equus Beds Aquifer. As the groundwater level dropped, it accelerated the flow of contaminated water toward the city's water wells.
The city devised a $550 million recharge project to pump water out of the little Arkansas River, treat it, and put it back into the aquifer, hoping that raising the groundwater levels would push the saltwater away from the city's wells.
Today, Cheney provides 65 to 75 percent of the local supply and the Equus Beds contribute 25 to 35 percent.
Farmers, industry and other cities also draw from the aquifer. The state has issued water rights that allow people to take out more water than nature can put back in.
It's simply overappropriated, said Tim Boese, manager of Groundwater Management District 2, which includes Wichita's well fields.
About 550,000 people depend on the groundwater in District 2's 1,406-square-mile area.
Here's how it's split up:
* Irrigation of crops: 50 percent
* Cities: 24 percent
* Industrial use: 13 percent
* Recreational and other uses: 3 percent
About 10 percent is pulled away by river systems.
For the moment, there's plenty of water to go around, mostly because of several rainy years, Boese said.
"But eventually the city will have to pump their entire rights out of the aquifer," he said. "Eventually, we'll have another drought."
Boese is part of the Wichita Water Utilities Advisory Committee that recommended that the City Council go ahead with the next phase of the aquifer recharge project that can pump 30 million gallons a day back into the ground.
That's water that can be used in the future.
But it's also essential to stopping contaminated groundwater leftover from salt mining and oil field production from flowing into the well field and farming wells.
That appears to be working — the salty flow has slowed by about a third, according to HDR's report.
But the plume is still inching its way near the edge of the well field.
Not everyone agrees that the city should press forward with the next step in the recharge project given its affect on water rates.
HDR recommended the city reduce the size and cost of the project, at least initially.
But City Council members recently approved the rate hikes based on the full-scale aquifer recharge, noting that the difference came down to only about 11 cents a month for average residential users.
Vice Mayor Jeff Longwell opposed the hike, which will cost the average household about $2.91 more a month this year and $4.19 more a month next year over current rates.
He said continued conservation and more-efficient irrigation and industrial cooling systems may drastically reduce the city's long-term needs.
"It seems we're setting ourselves up for future burdens for the rate payers," he said.
Fixing pipes
A few fixes could help Wichita meet its projected needs in the short term.
One is installing larger air valves in the pipe that carries water from Cheney Reservoir to Wichita.
It was made to carry 80 million gallons a day — but undersized air valves limit its use to 72 million gallons a day.
Another is replacing the pipe that runs from the Bentley well field to the city so that it can carry up to 30 million gallons more a day.
For example, average daily consumption is expected to grow from about 67 million gallons today to 101 million gallons in 2050.
Peak demand, which usually happens on a summer day, is expected to climb from 133 million gallons to 201 million gallons in 2050.
Many ideas for new water sources have been proposed. The most prominent lately has been the potential to pipe water from El Dorado Lake, a reservoir about 30 miles northeast of Wichita.
City Manager Robert Layton said leaders from both cities are trying to arrange a meeting to discuss possibilities.
"I'm not so much concerned about what would happen today under (drought and maximum use days)," said Layton. "You're just barely short today. And you can handle the worst-case scenarios with conservation."
But he said the city needs to focus on the trends and make sound decisions so that enough affordable water is available for years to come.


Remember 1 inch of rain on 1000 SQ FT roof  equals 623 gallons of FREE water......

1 comment:

plumbing said...

Maybe because they are looking forward for sustainability.They are figuring out if they can satisfy the needs of their consumer and give them the good service.That's only my opinion.