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A pond approach to water savings

Evaporation, weeds and leakage can wreak havoc
By: Gloria Young, Reporter
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DLD Service
Phone:  (916) 768-7017
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Ponds add beauty to the landscape but they are not just for looks. For homeowners, ranchers and farmers in the foothills, they’re a scenic way to maintain irrigation water.
They’re becoming an even more valuable resource as the impact of the drought hits water supplies. Handling maintenance issues before the heat of summer can  ensure that ponds  are at their peak capacity when they are needed most.
Many ponds in the area receive water from the canal system of the Placer County Water Agency and the Nevada Irrigation District.
“It’s measured by a miner’s inch – a unit of measurement developed during the Gold Rush,” explained Dana Andrews, owner of DLD Service in Loomis. “One miner’s inch amounts to 11-and-a-quarter gallons per minute. That’s not a lot. An open hose is 22 gallons a minute. ... Most people who have any kind of agricultural operation or more than five acres want 2 miner’s inches of water.”
With the possibility of water agencies cutting back deliveries by as much as half, conserving pond water and reducing problems that cause water loss become even more important, he said.
According to Andrews, the most common reasons for pond water loss are evaporation, plant growth and absorption into the soil.
Evaporation is propelled by water temperature, air temperature and the wind.
“A one-acre pond will lose 9,500 gallons of water every day,” Andrews said. “We can’t change the air temperature or the wind. But getting the water temperature down vastly changes the evaporation rate. If water (temperature) is in the 80s, the evaporation rate is huge. But if you can bring it down into the (degree range of the) 70s, you’ll have a 15 to 20 percent change.”
An efficient way of lowering the temperature is an aeration system, which takes cold water from the bottom and brings it to the surface.
Ponds also lose water through leakage, caused by erosion or ground-burrowing animals such as squirrels, moles, muskrats and beavers.
“They’ll dig a hole right through the levee,” Andrews said.
Fixes involve excavating and resealing.
Weeds are another water nemesis.
“Think of a pond as a garden,” Andrews said. “You’ve got cattails, duckweed (and other species). Some of these are huge — growing up to 8 to 10 feet tall. In a one-acre pond, they will consume 4,000 gallons of water a day.”
Most years these plants are dormant during the winter and have a growth cycle that runs from April to December. But this year, Andrews is seeing unusually active weed growth.    
Getting these invaders under control depends of the size of the pond and the size of the problem.
“We come in and treat them with aquatically approved herbicides,” Andrews said. “One of our tenets when we work in the water is not to harm the wildlife or have our chemicals go downstream.”
Typically a one-acre pond will need two treatments over a 30-day period to handle the problem.
“After we have controlled the weeds, at the customer’s request we’ll come out and remove the dead matter,” he said. “That is for aesthetics. It will dissolve in time. But it is not the prettiest thing in the world so many customers like to get it out of the water.”
These days, there’s a move toward using alternative methods to control plant growth without the use of chemicals, which can work well depending on the circumstance.
“Barley straw, grass-eating carp and other natural measures are out there,” Andrews said in an email. “We have found for now that aggressive herbicide treatment followed later by other remedial treatments or efforts give the best long-term results.”
For do-it-your-selfers, he cautions against buying weed-control chemicals out of state.
“It is absolutely illegal to do that,” he said. “You can buy chemicals (in California for weed abatement), but they must have the Cal/EPA decal on them.”
A common mistake he sees is customers cutting the weeds to remove them from the water.
“It’s not a good idea,” he said. “One way aquatic plants propagate is called segmentation (or fragmentation). When you cut a plant, you’ve made two plants. Those floating pieces will reattach to the pond and grow more.”
Loomis resident Mike Shellito’s pond is approximately a half-acre in size and fed by rural runoff. So he hasn’t seen significant water loss through the dry winter.
However, he’s preparing now for drought-related issues that may arise later.
“We called Dana to clean it out and remove a lot of sediment and material to create more capacity,” he said.  
In addition, Andrews repaired a leak in the levee and rebuilt a section that was perforated from muskrat and beaver visits. He’s also installing an aerator.
Shellito estimates Andrews removed about 120 yards of sediment and muck that had accumulated on the bottom of the pond.
“It holds about 50 percent more than it used to since we removed the sediment,” he said. “Instead of being 4 to 5 feet deep, it is 7 to 9 feet deep.”
At the time he and his wife purchased the property, the pond was more of a recreation amenity
“There was fish and we had it stocked with bass,” he said.
But it became the centerpiece of the irrigation system that was updated five years ago.
“Our property is on canal water from PCWA,” Shellito said. “We had water fed to the property from April to mid-October. We would irrigate using the irrigation canal water, just moving hoses and spigots around the property.”
Now, during the warm months he pumps water from the pond for irrigation.
 “Because it is substantially fed throughout the year from rural runoff, it really lessened our demand on PCWA water,” he said. “It’s just a more efficient way of doing it.”
Auburn residents Russell and Pam Tweet’s quarter-acre pond gets  water from the Nevada Irrigation District.
“We have always used it for irrigation,” Russell Tweet said.
A pump installation in the pond delivers water for fruit trees, a vegetable garden and landscaping.
After various remedies did not  solve a long-time leakage program, he called on Andrews for help last fall.
“He took out the old dam and reconstructed more of a spillway ...,” Tweet said. “It has worked perfectly and allowed a little more capacity to the pond. When there’s a lot of water going through there, you don’t have to worry about leaves or sticks blocking the outflow to the pond.”
The concept was a little different from what Tweet had in mind, but he’s very pleased with the way it functions.
“Even with the heavy weekend of rain back in February —  we got 9 inches in three days — it handled it superbly and the pond’s boundaries didn’t overflow.”
Other ways to save water include irrigating at night, reviewing sprinkler use and installing a  larger pump that allows for shortened cycle times, Andrews said in an email.