Wednesday, March 31, 2010

The Aging of Our Ponds

Part Three – The Aging process

I apologize for leaving many of you hanging regarding this four part series, “The Aging of our Ponds” which I started back in October of 2009. In the process of soliciting information from aquatic biologist’s for solutions and strategies for our ponds, I got distracted with the busyness of all that we have been doing and neglected to follow-up. And I know many of our members are curious about the ponds and are following this series because of the comments I have received. Again I apologize for the information delay. Here’s a re-cap of what we have covered so far.

In Part I of this series we covered “The Function of Our Ponds”, that they hold more then just strategic value to hole #’s 1, 9, & 3 but are crucial for irrigation water storage. Without irrigation water there is no Granite Bay Golf Club. In Part II we covered “The History of our Ponds” which discussed in part the regulatory concessions that were imposed during their construction. This included the replanting and establishment of the natural vegetation immediately following the pond’s construction. This natural vegetation lends to the beauty of the course, but contributes to the natural aging process that potentially impedes water storage and flow to our pump station.

In Part III it is time to cover this actual aging process, or what is referred to as “Eutrophication”. The following definition excerpts are from Wikipedia. “Eutrophication is frequently a result of nutrient pollution such as the release of sewage effluent, urban stormwater run-off, and run-off carrying excess fertilizers into natural waters. However, It may also occur naturally in situations where nutrients accumulate (e.g. depositional environments) or where they flow into systems on a ephemeral (short-lived) basis. Eutrophication generally promotes excessive plant growth and decay, favors certain weedy species over others, and may cause a severe reduction in water quality.”

Golf course turf is an incredible user and filter of nutrients, limiting or eliminating their contamination of streams, lakes and ponds. Therefore most of the aging or Eutrophication of our ponds can be attributed as a “Naturally occurring… depositional environment.” This means that when all of that vegetation surrounding our natural ponds goes dormant in the winter, the biomass remains in the ponds which both add and deplete nutrients as this biomass decays. Additionally the north end of George’s Lake (#1 & #9) is fed by Linda Creek, which can feed the pond with sediment and potential nutrient run-off from upstream.

All of these mostly naturally occurring inputs along with virtually no maintenance to these ponds over the years have produced an environment, which certain aquatic weed species have flourished from year to year as well as an substantial expansion of the shoreline vegetation.

The last two years since my arrival at Granite Bay, George’s lake has been covered with a weed called Mosquito Fern (azolla spp.) and Duckweed (lemna spp.). These are both free floating aquatic weeds that are unsightly but actually help with water quality by shielding the sun which heats up the water establishing other more noxious weed species such as Filamentous Algae (cladophora spp.). In the years prior to my arrival George’s lake was starting to have a real problem with Creeping Water Primrose (jussiaea repens). Pests such as the above mentioned algae and water primrose are not only unsightly and invasive but cause some real problems with irrigation water flow to the pump station. This is because their underwater structure fills the water column obstructing flow as well as clogging intake screens and filters.

Bottom line our pond’s need to be managed better. We need to do more strategic herbicide applications to prevent and keep in check both unsightly weeds such as Mosquito Fern and noxious weeds such as Water Primrose and Filamentous Algae. Along with strategic herbicide applications we need to reduce the encroaching vegetation and remove or harvest the excessive biomass. Our specific plan will be covered in Part IV - The Solutions for our Ponds. Stay tuned.

Summer photos of Georges Lake
Closeup of filamentous algae

 Creeping primrose

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