New Times / News
The following articles were printed from New Times [newtimesslo.com] - Volume 28, Issue 18
Atascadero Lake gives up its muck
BY JONO KINKADE
Atascadero’s nutrient-rich nuisance has been dug up and trucked off, giving city officials a break from the bizarre biological events that popped up in recent summer months.
The city recently removed a buildup of silt and soils from the Atascadero Lake. The dredging is one thing crossed off the list of a slew of lake maintenance aimed to address what has become an ecological can of worms. The soil build-up in the south end of the lake, where little water currently stands, became a problem after a combination of low annual rainfall and accumulated nutrient-rich organic matter (mostly bird guano) made for very shallow waters. As the water temperature rose in the summer, high nitrogen levels caused an algae bloom, which, in turn, sucked up all the oxygen and caused a massive die off of the lake’s carp population, causing an estimated 400 to 500 fish to go belly up in the 1-foot-deep pool. Workers removed 10,000 cubic yards of sediment, weighing about 15,000 tons, from the lakebed.
The sediment removal increased the projected depth of the lake’s south side from 1 to 4 feet. More maintenance activity—like removing non-native vegetation along the banks—is planned once the city gets a Fish and Wildlife permit. Because the undertakings involve water and wildlife, the processes required for permitting are plenty. Public Works Director Russ Thompson said he’s hopeful that work can move along without too many hang-ups, especially after the fish die-off created a bit of a stink.
“I think it helped prove to the agencies that we had to get permits through that we do have a problem out here that needs some immediate attention, so I do think that did help expedite the process,” Thompson told New Times.
In the meantime, the soils are being tested for pollutants, pesticides, and heavy metals. The sandy composition and high nitrate levels make it very desirable for agricultural uses. The city plans to put it to use in park maintenance, and may give some away to interested residents, with only one catch: This time, they have to do the hauling.