By Charles Layton
The primary cause of last Wednesday’s unusually severe flooding, Neptune Township officials say, was the collapse, one day earlier, of an old culvert beneath the intersection of Broadway and Central Avenue.
That culvert carries storm runoff to an outlet at Fletcher Lake.
They say that the culvert – which is a one-foot by eight-foot box — became clogged with debris carried by the fast-running water. Eventually, workers managed to clear that debris, after which the water level on the flooded streets receded.
However, the collapsed culvert must now be repaired, which will take additional time and add to the cost of the Broadway drainage project, which has been plagued with unforeseen delays since late last year. The project — to replace an antiquated drainage system down the entire length of Broadway and then into Fletcher Lake — was already scheduled to cost just over $1 million.
Leanne Hoffman, Neptune’s director of Engineering and Planning, said in an interview on Monday that she was working with the contractor, James R. Ientile Inc., to arrive at a price for replacing the failed culvert. The Township Committee, which meets next Monday, will then need to authorize the work. She said it might then take the contractor four to six weeks to get the materials on site.
The work itself will involve digging up the Broadway-Central intersection, which will be another inconvenience to those living nearby. At present, the collapsed culvert is covered by large sheets of steel in the middle of the intersection.
The Broadway project has involved the laying of a new system of drains and underground pipes all the way from Lawrence Avenue eastward to Central Avenue. That system of pipes conducts water downhill to Central, then makes a right turn and runs underneath the tennis courts. At the playground beside Fletcher Lake, the system turns left and empties into the lake.
The original conduit to the lake is very old. The project includes the addition of a new conduit, running alongside it, consisting of twin pipes, which will carry 30 percent more water than the old conduit. The old and new conduits combined will therefore have a carrying capacity 130 percent greater than the old system alone.
Even so, Hoffman and Assistant Business Administrator Vito Gadaleta, who was also present during the interview, said they could not guarantee that the new system – once complete – will put an end to all flooding in the Broadway-Central area. Gadaleta said last week’s storm produced 1½ inches of rain in 30 minutes, “which is beyond a 25-year storm.”
“You really can’t design any system to handle that flow,” he said.
Hoffman said workers were forced to react quickly last week when they learned that a major rainstorm was on the way. Their task was complicated by the unexpected collapse of the culvert underneath Broadway.
Workers made a temporary connection between another box culvert, on the north side of Broadway, and the twin pipes of the new conduit system, Hoffman said. In doing so, they patched around a conflicting sewer pipe in a way that partially obstructed the flow of storm water coming into the box culvert – an arrangement some of the area’s residents have criticized. Hoffmann said that temporary connection will now be removed and a new arrangement made so as not to constrict the drainage pipe.
Another problem of concern to residents is the way debris carried by storm water tends to clog the street drains, particularly at the intersection of Beach and Broadway. Hoffman said an extra drainage system will be installed there, which should be of some help.
In short, the main tasks remaining are (1) to fix the culvert that collapsed, (2) to reconstruct the box culvert on the north side of Broadway near Central, (3) to provide additional drainage at Beach and Broadway, (4) to complete the work on curbs and handicapped sidewalk ramps all down the street and (5) to repave the entire length of Broadway.
All of this, said Gadaleta, will produce a system that is intended to handle a 25-year storm. However, said Hoffmann, “I can’t guarantee that it’s never going to flood there again.”
The time frame for the remaining work remains unclear, but Hoffmann said the Township is working under an end-of-the-year deadline, which it must meet in order to retain the DOT funds allocated to the project.