Runoff Overwhelms Old Stormwater System
CHATHAM – It wasn't until 2004 that Dr. Neill S. Cowles noticed flooding in the parking lot of the Crowell Road optometry office he'd built in 1971. Runoff from Crowell Road began to flood the property's parking lot during heavy rains, sometimes three or four inches deep, but would usually drain quickly.
It was clear the runoff was coming from the roadway, and he asked the town to correct the problem. Some work was done on the system, but it had little impact. And then came the night of Aug. 18, when a deluge of some five inches of rain fell within the space of about two hours.
Water quickly filled the crawl space of the 1,500-square-foot building and rose seven to eight inches into the first floor, destroying heating and air conditioning systems as well as computers and other equipment. The damage forced the practice to close down for three months while repairs were made.
“We were down to basically just the studs,” Cowles said of the work necessary to fix the damage from the flooding. He expects to finally reopen next week.
Next door, Elizabeth and Robert Crowell had a similar problem; the same storm left 32 inches of water in their basement, destroying just about everything stored there. It took days to pump out all of the water.
Both owners point to stormwater runoff from Crowell Road as the cause of the flooding. Town officials don't disagree, and in an apparent acknowledgment of the problem, built raised berms at both properties' driveways and along sidewalks, as well as providing sandbags to prevent further flooding.
At the root of the problem is a combination of new development along Crowell Road and an old drainage system that's inadequate for the amount of runoff now being generated.
The town is hiring a consultant to do an in-depth analysis of stormwater runoff for the entire area, stretching from Collins Lane to the intersection of Crowell, Stepping Stones and Stony Hill roads, according to Director of Natural Resource Robert Duncanson. The analysis will include inspecting catch basins; video taping pipes to determine if they are clear or if obstructions are blocking the flow; determining how much runoff the road surface as well as properties along the road contribute; and calculating drainage for the area to determine if development over the past few decades has outpaced the system's capacity.
If it turns out that the system is inadequate to meet the current stormwater load, funding may be sought through town meeting to upgrade drainage in the area.
Duncanson said he did not know the age of the Crowell Road drainage system. “I suspect it goes way back,” he said. It certainly predates much of the development along the road during the past two decades. The Lake Street housing development added a significant amount of pavement uphill of Crowell Road. Development of the department of public works property 10 years ago added thousands of square feet in additional pavement. The nine-lot Kendrick Harvest subdivision was developed about a decade ago, and more recently the three-lot Hydrangea Way development was built.
While most, if not all, of the developments were required to install their own drainage, two factors could change how runoff from subdivision and large swaths of pavement might impact the general area, Duncanson said. Over time, things settle, and drainage that once went into catch basins may not bypass them. “Driveways settle over time and those kinds of things happen,” he said.
Secondly, when there's a major downpour and several inches of rain falls in a very short period, such as happened Aug. 18, runoff can flow over catch basins or structures designed to capture stormwater can become inundated and not function properly. Duncanson said the study the town is commissioning will determine where the runoff came from in the case of the Aug. 18 situation and whether the town was totally or partially responsible.
That could have significant implications. Cowles said although he tried he has never been able to get flood insurance for his building, so the damage from the summer storm isn't covered. He said he intends to submit his bills to the town's insurance carrier. Duncanson said the town's insurers are dealing directly with both Cowles and the Crowells.
Slightly more than a half-mile area contributes runoff to the Crowell Road drainage system. “All that drainage is kind of tied together,” Duncanson said. The system that collects the runoff discharges into an old cranberry bog north of the Crowell Road-Stepping Stones Road intersection, behind the J.W. Dubis and Sons construction yard off Stony Hill Road, at the headwaters of the Frost Fish Creek system. Officials inspected the two discharge pipes and they appeared clear; one was slightly collapsed, Duncanson said, but that didn't seem to impact the flow.
Cowles said the work done on the drainage system about a decade ago didn't stop flooding during major downpours. The runoff comes down his crushed stone driveway, he explained, and leaves a pile of stones at one end. At times, he said, he's seen so much water in the roadway that he's concerned vehicles will hydroplane and get into accidents.
“It's scary. We stand here and watch it come down the driveway and you hope it's going to stop,” he said.
Cowles said he was able to work with other optometrists in the area to ensure that patience were taken care of, and his office staff set up in his home to make calls to help facilitate patient treatment. He's essentially been out of work for the past three months.
Duncanson said the study should get underway in the next week or so and has an aggressive 45-day time frame for completion. He hopes to have a final report by the first of the year, so it can be determined if a warrant article is needed to fund repairs or upgrades. It can't happen too soon for Dr. Cowles.
“Now every time we get a downpour, I get panicked,” he said.