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The findings aren’t yet conclusive, but there are signs Laguna Joaquin may be starting to recover from the chemical application that killed hundreds of fish last week. Tests Monday and Tuesday found improving oxygen levels in the man-made lake.

The tests, measuring dissolved oxygen in the water, were done by Community Services District staffers and by Laguna Joaquin neighbor Larry Shelton, a retired environmental scientist who lives on the lake and serves as a Rancho Murieta Association director.

CSD readings for dissolved oxygen taken at the lake Monday show a marked improvement over readings taken Friday, according to Ed Crouse, the CSD’s interim general manager. Friday’s oxygen readings were at levels that would stress aquatic life; Monday’s were into the healthy range.

“If you go out and look at the lake, it looks stable,” Crouse said Monday afternoon. “I mean, I’m not saying it hasn’t been stressed. ... The fountains are on (to help oxygenate the water). They’re going to be running those 24/7. It’s cooler temperatures, so that allows more dissolved oxygen to stay in the water, stay in solution. Those are all pluses. So I think we’ve turned the corner.”

Shelton, who has been critical of the CSD’s handling of the lake, also has seen improvement in his readings, taken Monday and Tuesday. He has been testing the lake’s oxygen levels since last winter.

“The lake is showing signs of recovery, with better oxygen levels and numerous small fish near the surface,” Shelton texted Tuesday morning, after his tests.

In response to an RMA request, the CSD applied copper sulfate to a small part of the lake early this month to manage algae that was gumming up the RMA’s lake pumps. The CSD says it has used the chemical and the approach many times in the past with no problems. The compound depletes oxygen from the water.

This year, however, the Cosumnes Irrigation Association ditch, commonly called the CIA ditch, which brings fresh water from the river to Laguna Joaquin, has been closed since the end of June to allow the ditch to be piped through the Murieta Gardens commercial development project on Jackson Road.

Shelton has criticized CSD’s handling of Laguna Joaquin, compared to how it handles the community’s other bodies of water.

Said Crouse in response: “I think everybody recognizes that while they would like Laguna Joaquin to be a pristine lake, it will never be as pristine as a water-supply reservoir. This is a detention basin. Water that’s flowing into it, other than at times when the CIA ditch flows in, and there’s rain runoff, it’s just runoff from irrigation, so that brings its own host of nutrients into the lake that cause algae to grow and the like.”

The RMA and CSD met Monday morning to review what had happened and how it can be addressed going forward.

Crouse said his organization will examine:

  • How it responded to the situation Friday through the weekend
  • Its chemical application procedures for algae control
  • The possibility of more testing as part of those application procedures

He said RMA will hold off on using Laguna Joaquin’s water for irrigation until tests come back determining whether algae that has appeared in the lake is blue-green algae, which can be toxic.

He also said CSD is continuing to push the contractor to complete work on the CIA ditch. Crouse said the likely completion date for that work is the end of next week. In the meantime, he said, CSD will continue to flush street hydrants into storm drains that run into Laguna Joaquin, bringing more fresh water to the lake.

Daniel Maglionico's picture
Joined: 08/08/2007
Posts: 207
Post rating: 24

Laguna Joaquin

Are the dead fish coming back to life?

David Houdeshell's picture
Joined: 04/21/2008
Posts: 42
Post rating: 36

Copper Sulfate Is Not Going Away Unless You Dilute The H20

Copper Sulfate doesn't go away it settles at the bottom of the lake and you have to replace the water it does not dissipate. It is poisoned. You would have to pump thousands of gallon to reduce the PPMS to acceptable levels.


You'll die if you drink it and it's going to farmland. I can repair this entire lake organically and have it be crystal clear,  drinkable and no algae.

David Houdeshell

Topgun Enzyme And Microbial


Roger Brandt's picture
Joined: 09/30/2007
Posts: 9
Post rating: 13

CIA Ditch / Laguna Joaquin

FYI: Good news for the front lake.  Yesterday, Friday 8/19, CSD personnel & John Sulivan were at Granlees Dam and opened up the gate that supplies water to the CIA Ditch. As of tonight, 8/20/2017, fresh water is flowing in to Laguna Joaquin and the level is going up.

Roger Brandt

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