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Laguna de Santa Rosa Problems

I have been puttering around with this – don’t know quite which way to go – if any.

The outline below is a short discussion regarding some of the outgoing problems in the Laguna de Santa Rosa. The Laguna be listed as impaired for sediment, temperature, lack of DO and nutrients (P and K).

Below is a short review of what is going on – then – some legal considerations. I would like to know what you think.

In review of the document Enhancing and Caring for the Laguna de Santa Rosa (Anna Sears, Joseph Honton) you will find scarce mention of nutrients (from waste water discharge and other sources – Ag) as one of the limiting factors causing growth ( as a biostimulant) of Ludwigia ( a serious nuisance plant).

This misdirection and other (political factors) has resulted in activity to control Ludwigia via the application of extremely large amounts of herbicide chemicals.

A reading of the Ludwigia Task Force meeting notes indicates limited efficacy of the herbicide Glyphosate, and inability to mechanically remove biomass from flooded wetlands (CDFG site) and other locations ( in the year one review)

In year two (CDFG site), due to limited success, large amounts of Triclopyr, a broadleaf-specific herbicide by the trade name Renovate (Renovate has been approved for use in aquatic wetland settings) .

Some success of limiting Ludwigia biomass was noted in the channel, but flooded fields maintained a high level of Ludwigia biomass. Stream bank reduction of biomass was also a problem due to sediment. Nutrient enrichment never being mentioned as a problem.

Year two summary of treatment: Both the SCWA and CDFG sites were treated with Glyphosate and Triclopyr. Glyphosate areas were treated at 3 qt/acre, and Triclopyr sites with an initial 2 qt/acre, and 1 qt/acre followup. Both Glyphosate and Triclopyr sites experienced touchup application where initial treatment was not effective.

Mechanical removal of biomass occurs with an excavator – tractors.

At this point, no effectiveness trends can be seen based on different strategies. A suggestion was made that Imazapyr (trade name Habitat – NOT USED IN THE LAGUNA) may not be as effective on Ludwigia as it is on Spartina. Sites that employ a persistent removal program appear to be more effective than those that only use herbicides. Ultimately, there are more questions than answers.

Suggested plan for 2007 plans (SCWA): Herbicide application of Triclopyr at 1 qt/acre, with mechanical removal of the densest areas. Main Channel East: north bank was treated and removed in 2005, while south bank had treatment only. No action was taken in 2006. Plan to remove biomass from South side only, followed by 1 qt/acre treatment with Triclopyr on both banks. West of Stony Point, spot treat with 1 qt/acre Triclopyr.

Legal Considerations

It is obvious what is going on is experimental, with large amounts of herbicides and stream manipulation occurring without benefit of any environmental review. It appears as the project is flying by the seat of the pants – not totally backed up by science.

The EPA is on record that an NPDES permit is not needed for herbicide (Aquatiic Pesticide) application for mosquito vector control. There is a Ninth Circuit ruling that an NPDES is needed. I believe (but I am not sure – needs research) that the Laguna Foundation and Mosquito Vector Control applies for a yearly Nationwide (NPDES) Permit. It is not clear if all standards, analysis, and monitoring are consistent with CWA mandates. The RB says they are finding no residues – it is unclear as to the extent of monitoring.
The RB is concerned with weed removal an sediment mucking – no action taken, and the concern that there are no considerations being placed on habitat effects on stream condition and nutrient biostimulatory effects on nuisance plant growth.

RB monitoring needs to be assessed.

It is not clear if a CDFG 1600 (Stream Alteration Permit) has been applied for – and – if there was any environmental control or assessment placed on the project.

I am not sure what direction to take on this – if any.

Alan Levine
Coast Action Group
P.O. Box 215
Point Arena, CA 95468

Phone: Week Days 707 542-4408
Weekends 707 882-2484