The Meaning of Hahamongna

The original settlers of the region were sometimes called the Hahamongna Indians. The word means "Flowing Waters, Fruitful Valley" in the native Tongva language.

Hahamongna News

Title:

Rainfall refuels dwindling water supplies

Subtitle:

Date:

2010-12-25

Author:

Rebecca Kimitch, Staff Writer

Publication:

Pasadena Star-News

Content:

The storms that brought flooding and destruction to the region last week had something of a silver lining, at least to water managers.

The rains went a long way to refueling water supplies that were precariously low after three years of drought. More than nine inches fell in six days - half the region's annual average.

"This is a great boon and a fantastic way to start the water year. It is an outstanding start," said Shane Chapman, general manager of the Upper San Gabriel Valley Municipal Water District.

How much of the rainwater has been captured for future use won't be known for weeks or months. And regardless of how much is captured, some think more could have been done to keep water from flowing to the Pacific Ocean.

At this time last year, the water level in the Main San Gabriel Groundwater Basin - the giant aquifer that lies below the Valley and provides much of its water - was at a historic low.

Rains earlier this year have since improved the level, but it's still lower that water managers want.

"This rain is great for our water supply," said Carol Williams, executive director of the Main San Gabriel Basin Watermaster. "This is going to really, really benefit us."

Some of the rainwater will naturally make its way into the various groundwater aquifers that lie below the region and serve as both supply and storage for water.

"Anywhere it can puddle it can seep into the ground," said Brad Boman,

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engineering manager of the Water Division at Pasadena Water and Power.
But rather than naturally seeping, much of last week's stormwater was either trapped behind one of the county's dams or made its way down through a system of drains and channels to the Pacific Ocean.

Los Angeles County typically saves for later use only one-third of the stormwater that ends up in that system every year, according to Mark Pestrella, deputy director of the Department of Public Works. The rest goes to the sea.

That's because the department has to manage for flooding as well as water conservation, he explained.

"When you have so much coming in at one time, it is a dangerous act, trying to capture water. We get into flood control mode," Pestrella said. "It's just a balancing act ... we are seeking to save every drop we can."

The county ideally traps the water behind dams and gradually releases it into percolation ponds, or spreading grounds, where it can soak down to the aquifer.

Since Oct. 15, the county has collected more than 42,000 acre-feet of water for percolation. That's 20 percent of the total amount it usually puts into the ground every year. An acre-foot can supply two families with water for a year.

Besides the local supplies, the more than 17 feet of snow that fell in parts of the Sierra Nevada last week means that water imported from the North also will be easier to come by.

Already, before the recent snowfall, the state Department of Water Resources increased its projected deliveries of water through the State Water Project to 50 percent of requests, up from the 25 percent projection made last month.

"We don't want to be overly optimistic with most of the winter ahead of us, but recent storms have given us the best early-season water supply outlook in five years," DWR Director Mark Cowin said, even before the latest precipitation.

Last year, three years of drought had left water supplies so low that state water managers gave an initial allocation predicted at a mere 5 percent of requests - the lowest in four decades. That allocation was later increased.

Now state water projects' reservoirs are all at near-normal storage levels for this time of year.

But Debra Man, assistant general manager and chief operating officer for the Metropolitan Water District, which is charged with distributing imported water to Southern California, is only cautiously optimistic.

It will be months before she breathes a sigh of relief.

"It's great that early in the winter season we are getting major storms and snowfall, but we have also experienced in the past ... you can have an early, heavy above-normal rainfall, precipitation and the rest of the winter months become dry," she said.

And no matter how much it rains here, Southern California is still facing two serious threats to its water supply. First, a 12-year drought continues on the Colorado River and the largest reservoir it feeds, Lake Mead, is still at record lows.

Second, concern over the habitat of the San Joaquin-Sacramento River Delta has led to court-ordered limitations in how much water in Northern California can be pumped south.

"Whereas in past droughts, we were able to recover reserves during one or two seasons, now, with the pumping restrictions, we are unable to do that," MWD spokesman Bob Muir said.

So despite the rains, water officials continue to stress the need for conservation.

"People in Southern California understand how fickle the weather is. They are smart people and understand that we just went through three of the driest years and still need to conserve," Chapman said.

And, local water managers like Chapman are hoping to increase the amount of water that can be conserved from stormwater.

One of the problems preventing greater conservation of stormwater is sediment.

Because many of the slopes of the Angeles National Forest were charred by the Station Fire, when it rains, the resulting water brings with it mud and debris that ends up in the region's reservoirs and dramatically reduces their capacity.

So Pestrella said the county is working with state and federal officials to increase the speed sediment is removed from reservoirs in the future to increase their capacity.

Sediment-tainted stormwater also meant Pasadena Water and Power was only able to collect a fraction of the water last week than it normally would. The agency did not want to clog its percolation ponds with sediment, Boman said.

Water districts across the region are also exploring programs to increase stormwater capture - increasing the number of traditional spreading grounds to promoting the widespread use of innovative technologies such as permeable asphalt and concrete that allow rainwater to soak into the ground.

"It's very apparent that we have tremendous opportunities," Chapman said.

rebecca.kimitch@sgvn.com

626-962-8811, ext. 2105