On the morning of July 11, 2013 those living along Foster Brook which enters Lake George at Hulett’s Landing were surprised by the sudden raging water of a beaver dam breach. The upstream pond held back by the dam was estimated at about 9-acres and was all but entirely drained after the dam washed away.
The resulting flood downstream caused significant damage to parts of Foster Brook as well as some damage to homes and roads along the brook. One area severely impacted by the flooding waters was the offline sediment basin along Foster Brook near the Mountain Grove Church. The flash flood came down the mountain severely eroding streambanks and the rock vane built last year to address chronic erosion issues.
“We thought that the rock vane constructed last year would hold up to an Irene-like storm, but the beaver dam breach proved to be too big for it. We do think it did help to lessen the damage to the banks along the basin initially, until the system was overwhelmed. As the stream rose into the upper levels of the banks, it began to cut in behind the rock vane and that is when it started to really erode into the downstream bank. Fortunately the event was over fairly quickly and the water retreated to a manageable level,” Randy Rath, the LGA’s Project Manager, explained in a statement to the press.
In August, with grant money from the Froehlich Foundation, a donation of stone from Jointa Galusha, and design assistance from Washington County Soil and Water, the basin was cleaned and repaired and two small cross vanes were also installed. The cross vanes are designed to concentrate the water flow into the center of the stream channel and keep the banks from eroding again. The large cap stone rocks used are bigger, and should hold against similar flash flooding events.
Rath stressed the importance of the Jointa Galusha stone donation. “We really needed bigger stone to make this project work, and without the donation we wouldn’t have been able to afford it,” his statement said. “This area of the stream has had recurring erosion problems over the years, and we are hoping that with this latest work completed we can now focus our efforts on other sections of the stream that also need stabilization.”
LGA reported that this latest basin work took about three days at a cost of materials and labor just under $6,000. JVP Landscaping completed the work under a general permit issued through the Washington County Soil and Water Conservation District. The LGA and Washington County Soil and Water provided project oversight.
In 2009, working behind a double set of turbidity curtains, approximately 1,500 cubic yards of material were dredged from the delta at Foster Brook which improved navigation is believed to have led to the first smelt run there in years in 2010. That project took more than 15 years of planning and site work. A full report with photos of the 2009 project can be viewed in the Foster Brook Summary Report [pdf].
Photos: Above, the beaver pond after the dam break (LGPC-DEC-State Police Photo); below, streamwork shown in photo provided by LGA.