January 13, 2015 Wayland Surface Water Quality Committee (WSWQC) 59 Moore Road Wayland, MA 01778 thomas.largy@verizon.net Via Email Re:
2014 Summary Report Water Chestnut Harvesting, Heard Pond, Wayland, MA
Dear Committee Members: In accordance with the Order of Conditions, DEP File No. 322-0678, for the removal of Water Chestnut in Heard Pond, we are pleased to provide this summary report of the 2014 management program. On June 30, 2014, a pre-harvesting survey was conducted by Jeff Castellani of Lycott Environmental (Lycott) to assess the density and distribution of Water Chestnut (Trapa natans). Water Chestnut plants were observed consistently around the shoreline within the floating-leaf and emergent aquatic vegetation and extended up to ten feet into the open water. More specifically, Water Chestnut growth was observed at a density of approximately a dozen plants per 100’ x 100’ grid on the west, north and east shorelines. The south cove exhibited similar densities and extent except scattered growth was observed throughout three-fourths (¾) of the south basin in the open water. Excluding the southeast corner where the river runs adjacent to the wetlands, the infestation would be described as scattered coverage of trace to light density (0-20) or up to 20% density. The only area that would be characterized as moderate density was in the opening to the wetland area in the southeast. Many of the Water Chestnut plants co-existed within other species of floating-leaf vegetation primarily, White Water Lily (Nymphaea odorata), and emergent vegetation primarily Pickerelweed (Pontederia cordata) and Buttonbush (Cephalanthus occidentalis). Based on these observations, the 2014 Water Chestnut infestation appeared to be broader in density however consistent in coverage than that observed in 2013. On Heard Pond, nutlet germination and rosette development typically takes place in mid to late June. The majority of rosettes had surfaced by the June 30th survey, rosettes were 4” to 8” in diameter with some still suspended in the water column. In general, Water Chestnut germination and rosette growth observed on area water bodies in the spring of 2014 were advanced compared to the infestation on Heard Pond. However, those area water bodies are nutrient rich river systems and are typically ready for an initial harvest by the second week of June. Hardy Pond in Waltham Massachusetts, with a similar mechanical / hand harvest history, exhibited the same phenomenon as Heard Pond in recent years with respect to a fluctuation in Water Chestnut plants observed / harvested; 2012 – 835 plants, 2013 – 4,320 plants, and 2014 – 1874 plants. Based on the growth present at the time of the survey, it was recommended the hand-pulling event commence the second week of July.