By Jim Steele ?
The report is out. The agency in charge of reducing nutrient inputs to Clear Lake, the Regional Water Quality Control Board (RWQCB), provided an update on its master plan for restoring lake inputs to normal visit www.swrcb.ca.gov/rwqcb5/water_issues/tm.
Hmm, normal, there”s that word again. I believe it”s been said by some writers that the lake has had algae for thousands of years with the implication that what we see is normal.
Well, if you go back before the advent of heavy equipment in the Clear Lake watershed, you would certainly have a different lake and ecosystem.
Some of the parameters of that lake would not be hard to imagine.
The lake would still be warm and shallow and very productive because of the micronutrients available to the primary producers. These come from volcanic soils high in phosphorus and iron.
Primary producers such as phytoplankton and rooted aquatic plants rimmed the lake and filled wetlands at each stream exit.
The microscopic phytoplankton would be mostly made up of true algae and cyanobacteria capable of converting energy by photosynthesis.
Wildlife would depend on this base, building until they formed the food web we see today.
This sounds pretty normal so far.
The difference today is that many of the processes stabilizing this system have been altered because people had the means. Most of the emergent vegetation rimming the shoreline has been removed.
These calmed wave action, reducing shore and shallow bottom scour. Too much shoreline is now rimmed with fill and retaining walls that magnify the effect of waves.
The wetlands have all but disappeared except for the notable exception of Anderson Marsh. The filling or altering over 85 percent of the wetlands has removed the sediment filter for incoming water.
What runs off the land enters the lake rather than being captured by these necessary features. So now the lake gets the brunt of upland soil runoff with no wetland to trap it.
The streams have been mined for gravel and riparian destabilized and lost. The otherwise trapped sediments have made their way into the lake past the missing wetlands.
Erosion from streets, roads, off-road vehicles and projects proceed only slightly altered on its way.
Yes, this cocktail of nutrients overloading a warm, shallow, naturally rich lake will bring a normal response; bloom and bust cycles of algae and scum-forming cyanobacteria. No surprise.
The real surprise is the RWQCB report describing cosmetic best management practices (BMPs) for land disturbance as though it will make the necessary difference.
The project that could make a noticeable difference is the Middle Creek Restoration project, which is still in the process of buying out private owners.
This slow moving project is on track to take several more years and more than $40 million to reduce only 28 percent of the phosphorus load.
The restoration of shoreline and other wetlands are not on the table. Preparing for a warmer climate is not mentioned.
Also not being discussed is whether off-road vehicle parks on sensitive nutrient rich soils in the watershed of a very sensitive lake are even necessary or desirable.
Wouldn”t a less vulnerable watershed be better?
The word restoration is not used; instead we have BMPs such as water bars and reseeding to reduce impacts.
Not likely, since cyclic high rainfall years will still concentrate runoff and load the lake taking years to process through the system.
The level of thinking and planning will have to be much different to bring back a stable lake system. It doesn”t look as though we have solutions to match the problem. But then that”s normal.
Jim Steele is a retired Cal Fish and Game scientist, registered professional forester, part-time consultant and full-time Lake County resident-volunteer.
