LACONIA — Although Jewett Brook again jumped its banks and flooded properties at the foot of Winter Street during Wednesday's 5-inch rainfall, Luke Powell, assistant director of Public Works, said yesterday there is no prospect of reducing the risk of flooding in the foreseeable future.
Since 2008 Powell has sought to restore Jewett Brook, which would increase its capacity to carry optimal volumes of water while diminishing the risk of flooding. He took the initiative after Normandin Square flooded four times in three years —in October, 2005, in May and July, 2006 and again in April 2007. Since then Normandin Square has been spared, but, like this week, yards and cellars on Winter Street have filled with water a number of times.
Jewett Brook rises in Gilford, not far south of Swain Road, and flows northward to Liberty Hill Road, where it is fed by a tributary meandering southwest from Saltmarsh Pond. Paralleling Liberty Hill Road, the brook passes beneath County Club Road and the Rte. 3 and 11 Bypass and crosses the Lakes Business Park. At Hounsell Avenue, just south of the northern entrance to the park on Gilford Avenue, the main stem of the brook is joined by a major tributary that originates to the northeast, on the north side of Route 11-A about halfway between the bypass and Hoyt Road. From there the brook runs westward, roughly parallel to Gilford Avenue, skirts Tardiff Park and runs under Highland Street and Union Avenue before passing under the Normandin Square Apartments and Davis Place from where it empties into the Winnipesaukee River some 250 yards above the Avery Dam.
The brook, along with its major and minor tributaries, stretches for about five miles, with the main stem and its major tributary representing 3.5 miles. Its watershed covers 5.4 square miles, most of it in Gilford. Less than a mile of the brook flows through the city. Likewise, a small fraction of the watershed of Jewett Brook, which extends from downtown Laconia in the west to Hoyt Road in the east and north of Gilford Avenue south to the Belmont town line, lies within the city limits.
Following the flooding in 2007, the Department of Public Works (DPW) was awarded $100,000 in federal funding with which it underwrote two studies, one of the entire 5.4-square-mile watershed of Jewett Brook and another of the stretch from upstream of the Union Avenue Bridge to the Winnipesaukee River, a distance of about 1,200 feet.
The first study concluded that the main stem of Jewett Brook east of the bypass was "good", but found the condition of the stretch through the city, from the bypass to the river, only fair.
The second study, prepared by Dubois & King, Inc., found the capacity of the stream bed under the Union Avenue bridge, the dimensions of which have been shrunk by accumulated sediment, to be the principal choke point. The engineers concluded that neither widening the bridge nor raising the roadway would be practical and recommended dredging the channel beneath Union Avenue as the most cost-effective means reducing the frequency of flooding.
However, dredging requires a permit from the New Hampshire Department of Environmental Services (DES). The agency has insisted that before seeking a permit to dredge, the city must first take to restore the capacity of the brook and reduce the flow of sediments upstream of the bridge and elsewhere in the watershed.
Powell said that DPW secured a $40,000 federal grant through DES to begin work upstream of the bridge. He said the department sought to negotiate an easement with the owner of the property adjacent to the bridge, which originally housed a Catholic school and was most recently a branch office of TD Bank, to restore the channel, but failed to reach agreement. Consequently, last year DES rescinded the grant.
Powell said that without the resources to undertake the improvements upstream that DES requires, efforts to alleviate the flooding are at a standstill. "Right now, there is nothing we can do," he said.
- Category: Local News
- Hits: 692