For the Montgomery area, the consequences of climate change will include more frequent and intense heat waves, heavier and more precipitation events, and increased flooding, according to Rutgers Climate Institute. Here are some things local governments and residents can do to adapt.
Photo caption: Stormwater surges by the old mill house off Dead Tree Run in Montgomery. Photo by Barbara A. Preston.
Stormwater Management Takes Center Stage
Cities and towns around the globe are seeing signs of a changing climate, from wildfires borne of drought in California, to rising tides in lowland cities like Miami, to repeated flooding in shallow river valleys, as we’re seeing in Montgomery Township.
The problem forces government leaders to re-think stormwater management in order to become more “resilient” to long-term changes in the climate.
New Jersey Governor Phil Murphy just signed a bill into law that will give municipalities the option to create stormwater utilities.
A stormwater utility fee is similar to a water or sewer utility fee. In essence, customers pay a fee to convey stormwater from their properties.
Such utilities would assess fees on landowners based on stormwater runoff to raise funds for stormwater management and to encourage landowners to reduce runoff.
“The problems are caused by too much rain, too fast, and too dirty,” said Steve Tuorto, director of stewardship and education at the Watershed Institute in Hopewell. The Watershed is one of New Jersey’s oldest environmental groups, with a focus on the Stony Brook and Millstone River watersheds.
On a recent visit, Tuorto stood by a three-dimensional model of our region that illustrates how Montgomery lies on a low plain, surrounded on three sides by Sourland Mountain, the Princeton Ridge, and Ten Mile Run Mountain in Franklin. The open side is where the Millstone River flows north, toward the Raritan River and Bay and, ultimately, to the Atlantic Ocean.
Besides the increase in rain, Tuorto points to local decisions about development that are contributing to flooding.
New Jersey is not only the most densely populated state in America, but it also has built more impervious surface than any other state — 12 percent of all land is covered with homes, offices, roads, highways, airports, and parking lots.
Impervious coverage prevents water from soaking into the ground and recharging natural aquifers. Instead, stormwater laden with pesticides, road salt, and other chemicals flows into storm drains, streams, and rivers, where it can lead to flooding.
“When impervious coverage is 10 to 20 percent of the land, what we call low density, that doubles the volume of runoff,” said Tuorto. “With medium density, at 30 to 50 percent, it triples run-off. Montgomery is low to medium in density,” he said.
The Watershed Institute is putting the finishing touches on a major area report on stormwater management that will provide analysis and recommendations to 16 municipalities, including Montgomery. Among the solutions the Watershed has recommended is to require small redevelopment projects to be designed to absorb stormwater on site, rather than put it into storm drains. Princeton recently amended its stormwater rules according to this advice.
Montgomery officials, including Mayor Sadaf Jaffer, say they look forward to seeing the Watershed Institute report.
“Environmental issues are among the most challenging we will face, and we need to look at all our options and have a forward-thinking approach,” the mayor said. “I am optimistic that we can cooperate with different levels of government and community stakeholders to find solutions. We need to be working together, across towns.”
Stormwater Management at New Municipal Building
One opportunity to reduce stormwater runoff comes in the form of Montgomery’s new municipal complex, said Township Administrator Donato Nieman. The current design includes two “rain gardens,” which are depressions designed to absorb rainwater rather than push stormwater into street drains. One of two existing detention basins is to be “refitted” to make it more effective at holding back stormwater.
In addition, there will be less impervious coverage. Comparing the new municipal building to the pre-existing ConvaTec facility, Nieman said: “We are reducing the total amount of impervious coverage and increasing open space.
Nieman also said the site will benefit environmentally by being connected to the township sewer system, rather than relying on the septic system that previously served ConvaTec. The site will be served by the Skillman Sewage Treatment Plant, which is state-of-the-art, he said.
Sewer System in Good Shape
One of the biggest flood risks to any city or town is an overwhelmed sewage treatment system. Plant operators can be forced to “bypass” the system and release untreated effluent.
Christopher Lalicato, who oversees Montgomery’s sewage treatment plants, is confident they are ready for almost any event, following the closing of two of the more vulnerable plants last year. Before they were closed, heavy rains last year forced two plants — the River Road and Oxbridge plants — to undergo “secondary” bypasses, meaning the effluent missed a final stage of treatment, but still met state standards.
The one remaining concern is the plant, near Rocky Hill. In extreme cases, it is at risk of flooding by the rising Millstone River. A plan is being developed to build a 14-foot wall, to protect the plant from rising waters. ■