Hayden Turek photos
Guided and supported by volunteers from the Mianus Chapter of Trout Unlimited, employees of the Wilton office of measurement science company Nielsen spent their global impact day outside this year, cleaning up the Norwalk River on June 2.

“Every year, Nielsen has one day where we block off an entire day of work to do a global impact day, and that’s what we’re doing today, here in Wilton,” said Nielsen analytical consultant Jackson Fallon at the Norwalk River Parks and Fields off Old Mill Road last week.

“We often try to partner with companies like Nielsen on their impact days, because it’s a great way to get a bunch of volunteers out to help clean the river, which is important; there’s always more to do,” said Jeff Yates of Trout Unlimited.

In blue Nielsen shirts and Trout Unlimited hats, the volunteers swept up and downstream, picking up trash, debris, and anything else they found polluting the river, along either bank, in the channel, and on the roadside.

“We’re picking up trash in a very visible place,” Yates said. “A lot of people come up and down Route 7. Most of the trash we’re collecting is along the Route 7 side [of the river] because there are 30,000 people driving by here each day.”

“When they see all these people picking up trash, it may make some of those drivers less likely to toss a water bottle or a coffee cup or a cigarette butt or any piece of trash out of their car,” he said. “It basically raises a red flag that says, ‘Hey — this is a river that people care about.’”

According to Fallon, the haul looked promising as the volunteers were finishing up.

“We’re probably going to pull over 40 bags of trash,” he said. “We’ve got large items as well, and I think we’re really making an impact on both sides of the river.”

“It feels really good,” Fallon said. “Just having people in the office know that they made a positive impact on something so close by, they’ll remember that every time they’re going home from work.”

Cleaning up the river, Fallon added, is as much a good time as it is a good thing. “It’s a great change of pace,” he said, “and I think most people find it enjoyable, and look back on it as probably one of the better days of the year.”

While Nielsen dedicated its 2016 global impact day to cleaning up the Norwalk River, the Mianus chapter of Trout Unlimited is working to protect, reconnect, restore and sustain the trout fishery year round.

Yates said the single greatest danger facing the Norwalk River in both urban and suburban environments is stormwater runoff.

“In the precolonial times, when it rained, the water fell on meadows and forests and soaked down through the ground. Some of it evaporated, some of it sank down to refill the aquifers and the ground water, and a lot of it flowed underground into the river as springs,” Yates said.

“What would happen is it would rain, and the river would rise slowly, get to a peak, stay high for a while, and then slowly drop,” he said.

Developing the virgin earth with impervious pavement over the last 200 to 300 years, however, has eliminated that slow trickle and replaced it with fast-acting storm drains that deposit stormwater directly into the river at rapid rates.

“Now, because we have paved so much of this watershed, when it rains, instead of taking 15 days for that water to slowly soak down and make its way to the river through the ground, it happens in 15 minutes,” Yates said.

There are a number of issues with this, he added.

Floods often tear out the trees that stabilize riverbanks, and with the torrents becoming more intense and more frequent, the river ecosystem has less and less time to correct for that unnatural erosion.

“The river channels are getting wider and wider. You might have had a river that was 10 feet wide and three feet deep and had lots of habitat for trout and other aquatic life. Now it’s 30 feet wide and one foot deep.”

Stormwater also carries pollution, which eventually makes its way from rivers like the Norwalk into Long Island Sound, creating hypoxic conditions.

“So stormwater is a huge issue,” Yates said. “We’re focusing on that; we’ve actually just applied for a major grant to do a stormwater mapping project for the entire watershed to identify the parcels that shed the most water through impervious cover, so that we can slowly work to do treatment options to disconnect them from the stormwater grid.”

Those treatment options are many, according to Yates. They include settlement ponds, rain barrels, raised garden beds, and engineered, pervious pavers that are porous and allow stormwater down into the ground.

“It took us 300 years to get to this point with the river; it’s going to take us twice as long and cost twice as much to unwind all that. It’s a lot of work, but it’s needed, because the river’s flooding very frequently now,” Yates said.