flow alteration. (MassDEP 2006). Aquatic Life, Primary and Secondary Recreation and Aesthetic uses are all impaired.
In 2001, DWM conducted three baseline lake surveys in Musquashcut Pond (DEP, 2006). While DO concentrations ranged from 6.4 to 9.3 mg/L, supersaturation occurred during two of the three surveys (as high as 130%). The concentrations of total phosphorus ranged from 0.041 to 0.11 mg/L at the deep hole station. Higher concentrations were measured in the samples collected from the unnamed tributary (ranged from 0.13 to 0.26 mg/L-DEP, 2006).
The midge problem in Musquashcut pond is largely driven by organic nutrient enrichment from failing septic systems coupled with changes in salinity dynamics due to the reduction of tidal exchange between the pond and estuary. Lawn fertilizers, yard waste, and surface runoff are also sources of pollution to the pond. Storm drains in Sheeps Pond which is connected Musquashcut Pond by an overgrown canal are suspected but unconfirmed source of contaminants (CEI 1999, in DEP, 2006).
In addition to high nutrients, pathogens from sewage, nuisance midge infestations, and potential sediment contamination from years of pesticide applications, Musqashcut Pond suffers from thermal pollution. The shallow depth and slow flushing rates in the pond result in high water temperatures that encourage the growth of weeds. The dense weeds further reduce circulation, and, in turn, encourage temperatures in the pond to rise.
Figure 1-2. Musquashcut Pond Tidal Restoration Project
There are two electric tide gates on two 7-foot box culverts located at Hatherly Road at the pond’s outlet to Musquashcut Brook. The original gates were installed during the 1930’s in order to maintain adequate water depth in Musquashcut Pond and in an effort to control a midge problem, water was exchanged in Musquashcut Pond once per month on a full moon tide, which remains the general practice today (Lefebvre et al. 2003).
In the mid-1990’s gates were installed to maintain sufficient water depth and to address flooding issues. According to a 2004 ACOE tidal flushing study, approximately 75% of the pond water is replaced during the monthly tide gate operations. The study found: 1) Even with the tide gates left fully open, there is no flooding along Musquashcut Pond during spring and normal tides; and 2) The pond will be able to accommodate at least 2 inches of runoff from the surrounding watershed on top of the peak spring tide water. In 2005, Massachusetts Coastal Zone Management accepted the restoration of the pond as a Wetland Restoration Priority Project. The Town Conservation Commission is working with CZM, the Conservation Law Foundation, NOAA Restoration and other partners to explore restoration options via altered tide gate management. Anther ecological problem associated with the temperature and chemical imbalances in the pond is a declining fish population.
South Coastal Watershed Action Plan 9/12/2006 Watershed Action Alliance