Algae bloom again
BY KELLY LOPEZ
The swirls of green algae are difficult to ignore and even more courageous to dive into. Summer has officially arrived and with it comes what has become an annual algae bloom in Canyon Lake.
Those who live around the lake, and especially those in East Bay, are scratching their heads again as to what causes the unsightly bloom and how can it be prevented and remedied.
Three things contribute to algae blooms, Darcy Burke, the Elsinore Valley Municipal Water District (EVMWD) board member representing Canyon Lake, said. The bloom is caused by water runoff from overwatering yards, lack of water movement in the lake and water temperature.
Of the three, she said, only the water runoff can be altered. The water temperature can obviously not be controlled. And, in the East Bay, where “no wake” rules are enforced, water movement is also not happening.
But, curtailing overwatering and the resulting runoff from soil and lawns can help the algae bloom dilemma, Darcy said.
Photo by Aimee Hunter.
The significant algae blooms in the East Bay occur this time of year when the weather warms up. This year, she said she was surprised to see the bloom had started earlier than in most years, considering the weather has been more temperate and the lake level higher. Having a more full lake allows for more movement and therefore less stagnancy and fewer algae blooms, she said. Obviously, the predicting of the timing of the algae blooms is an inexact science.
EVMWD and the Canyon Lake POA work in tandem when it comes to the health of the lake.
“EVMWD and the POA have a great working relationship,” Darcy said. Both parties have a strong stake in the health of the lake, for recreation and for drinking water.
EVMWD uses the lake’s water to supply the district’s water needs and the POA, of course, uses the lake for recreational purposes.
Right now, EVMWD is not using the water from Canyon Lake to supply its customers with drinking water. Darcy said the lake’s water right now contains unallowable levels of chemicals called polyfluoroalkyl substances (PFAS).
If PFAS are discovered at an unacceptable level, EVMWD said it will not use the water and takes immediate and appropriate action to ensure water meets state and federal regulation.
New treatment plans are being studied to find ways to remove PFAS from Canyon Lake’s water. PFAS are contaminants that come from man-made items. They are chemicals that are found in many household objects and end up in the lake due to runoff. Darcy said there are not necessarily more PFAS in the lake now than there were in previous years, but federal and state guidelines regarding what levels are allowable in drinking water have become more stringent due to more advanced technology in detecting the chemicals. Those new guidelines have the water in Canyon Lake falling above the usable limit.
EVMWD is part of the Santa Ana Watershed Project Authority, which is a group of five water districts in Southern California, all connected by the Santa Ana watershed. The project authority works to find solutions to make clean water efficiently and affordably.
Because EVMWD is not using and treating Canyon Lake’s water right now, it must purchase water from the Metropolitan and Eastern water districts, which is much more expensive than using water it owns in Canyon Lake.
The higher cost of drinking water is bad news for EVMWD consumers, but the resultant high lake level is great news for Canyon Lake recreational enthusiasts. Because the water district is not using Canyon Lake’s water, the lake level remains high, which is welcomed by boaters and all those who use the lake.
Canyon Lake is one of only two drinking-water reservoirs in the state that allows body contact. County Supervisor Kevin Jeffries, whose district includes Canyon Lake, successfully pushed for legislation that allowed to keep Canyon Lake a recreational lake as well as a reservoir for usable water. Because the lake allows for human contact, additional treatment is necessary when the lake water is treated.
Darcy explained that EVMWD tests the water before major holidays to ensure safety. Recently the water district took samples from its five pre-determined sites around the lake. They should have the results of the tests early next week before the big Independence Day weekend.
EVMWD and the POA have different responsibilities concerning the health of the lake. EVMWD is responsible for treating the lake water and making it safe for use and drinking. It is its responsibility for testing levels of unsafe contaminants and making sure any water the district uses for its purposes are safe.
The POA leases the surface water from EVMWD for recreational purposes. Hence, when the EVMWD gives testing results to the POA, it is up to the POA to resolve issues associated with using the water recreationally, Darcy said.
Various solutions to the lake’s current algae bloom that have been used in the past are dredging and alum treatments.
Dredging can help with lake health, in that it scrapes the bottom sediment that has accumulated over time and restores the depth of the lake. It’s also expensive.
The POA has used alum treatments, or aluminum sulfate, for many years to help with significant algae blooms. “Aluminum sulfate, or alum, is increasingly being used to fight algae blooms spurred by an overabundance of phosphorus from human activity,” according to National Geographic. Algae thrive on phosphorus, which is a substantial ingredient in fertilizers used to treat household lawns and plants.
John Holz, who spent decades of his life studying algae blooms at the University of Nebraska, explained that algae blooms have spiked because people have significantly increased the levels of phosphorus in lakes by over-fertilizing lawns.
“Rainwater plucks phosphorus-rich residue from these cultivated surfaces and trickles into waterways, serving up a treat for algae,” he said.
Alum treatments dramatically reduce the amount of available phosphorus in the lake, but if more nutrients are added to the lake every year, in the form of runoff, the treatments are less effective.
Algae can shade out and harm native plants that provide underwater animal habitats and some, like cyanobacteria, can give swimmers rashes or even flu-like symptoms.
Darcy welcomes questions and concerns from all Canyon Lake residents. She can be reached by calling (951) 634-9091 or by email at [email protected].