At the October Lake Committee meeting, Fred Lubnow of Princeton Hydro gave a presentation about the work they have done at Lake Holiday to date. Princeton Hydro has been monitoring water quality tests, collecting storm water runoff samples, preparing a mass balance analysis, and testing for algae. Their final report and a presentation will occur around March 2018.
Mr. Lubnow explained it is important to 1) collect data to assess the health of the lake and identify any potential problems early on; 2) to quantify source of Phosphorus as internal or external which then directs the best way to reduce algae; 3) to watch for trends over time and; 4) to educate those who use the lake how to best maintain its health. He stated it is also important to have data in order to apply for grant and funding requests which, even as a private lake, Lake Holiday may be eligible to receive since we are a part of the Chesapeake Bay watershed.
Findings from water quality tests so far have shown the Phosphorus levels to be relatively low, which is good news since that is what feeds algae growth. Mr. Lubnow indicated that one pound of Phosphorous serves as a food source for 1100 pounds of algae, so controlling Phosphorous is essential. He also noted that, based on this year’s testing, he would not likely recommend any need for an alum treatment at this time. He recommends continued testing at least 3 times a year – in April, in mid-summer, and in late summer.
Phosphorous levels can rise as fertilizers wash into the lake, which is why it is important to be sure to use only fertilizers that do not contain Phosphorous (by making sure the middle component number is “0”). It was also noted that many lawns may only require inexpensive lime treatments in lieu of fertilizer, which can be determined by a simple soil sample test.
Leaves are another source of Phosphorous. Therefore, please take advantage of the LHCC leaf bag pick-up service or use the yard waste dumpster, and avoid blowing leaves into the lake and culverts.
Despite the low Phosphorous levels this year, they did identify blue green algae in the lake, which has the potential to release toxins. Fortunately, the testing did not detect any cyanotoxins which are typically released during a bloom. Conditions that favor algae blooms are 1) warm water temperatures; 2) high Phosphorous levels, which can occur after a heavy rain from runoff; and 3) still water conditions.
Some vegetation in the lake is starting to re-emerge as the sterile grass carp are dying off. During their sampling on September 17 at Lake Holiday, they did identify hydrilla in the lake. Hydrilla is a non-native invasive plant which can have negative impacts on a lake’s biodiversity and on the sustainability of the fishery. It is always important to wash your boat’s hull and trailer before launching if used in a different waterway to prevent the introduction of non-native plants. He also spoke about vegetation islands to re-introduce native plants in a way that protects them from the grass carp.
(Submitted by Lake Committee)