A rain garden. Image by Montgomery County Department of Environmental Protection.

Maybe you’ve noticed: the Washington region is pretty wet. All that precipitation can become contaminated when it hits the ground, so communities need to prevent that polluted water from ending up in our streams and rivers. One way local jurisdictions are addressing this problem is through Green Streets programs, which corral and clean polluted water on public roadways.

The town of Edmonston in Prince George’s County is famous for its Green Streets. DC Water is likewise implementing a massive green infrastructure program to help address sewer overflows along with on-street installations. Montgomery County has also put in some Green Streets installations such as rain gardens, but their program has run into problems.

Since 2012, the county has completed 12 Green Streets projects and has an additional seven being designed now. Some are almost ready for construction. The Department of Environmental Protection used technical criteria (like distance from streams) to select the next round of neighborhoods for Green Streets. But when installing the gardens, sometimes the agency came across as “we’re here and we’re going to do this thing to your neighborhood.” Some homeowners have concerns about mosquitoes, people tripping and falling into the gardens, and litter removal.

As a result, some have resisted the new projects, sometimes in dramatic fashion: threatening lawsuits, putting up “no pits in my front yard”-type signs, and making their opposition clear to County Council. That's unfortunate, because these programs are essential to keeping our local waterways clean. The county's position is similar to when a utility needs to dig up a road for a gas line: while it solicits neighborhood involvement and tries to do its work sensitively, it has an obligation to act for the greater good.

Polluted stormwater poses a threat to streams and rivers

We get 40-50 inches of precipitation each year in the Washington region, on average. Before our area was colonized for farming and later, developed, it was part of a huge unbroken forest that stretched up and down eastern North America. Combine those things together, and you get a historically “spongy” landscape — one with large, deeply-rooted trees and soil that evolved to soak up all this rain and then gradually deliver it to the many streams that roll down our hills and into the Anacostia and Potomac rivers, and ultimately the Chesapeake Bay.

But in today’s landscape of development and pavement, the soil is no longer spongy. The pavement acts as a hard shell, so every time it rains the water whooshes off to the nearest low place.

Image by EPA.

Channels and gutters collect this fast-moving water and deliver it to our streams, carrying with it everything it picked up on the streets: fertilizers and pesticides, tire rubber particles, air pollution that has deposited back on the ground, dog poop, trash, and even heat from hot blacktop. This is stormwater, or polluted runoff, and it’s the biggest threat to our streams. All those pollutants stress fish and the insects they eat, and the fast-moving water scours out the stream banks, destabilizing aquatic habitats and dumping more mud and debris downstream.

An Audubon Naturalist Society water quality monitoring volunteer standing in a muddy canyon in Watts Branch, Montgomery County. Watts Branch has deeply eroded from stormwater as development has increased in its watershed in and near the city of Rockville.

Big municipalities, like DC and its suburban counties, are required to address this problem under the Clean Water Act by better managing their storm sewer systems and catching runoff before it hits the streams. Then, the water is treated and encouraged to filter into the ground, slowing the pace at which it discharges into streams. Cities and counties can restore streams to stabilize riverbanks and make better fish and insect habitat. This restoration is very popular because it makes a stream that previously turned muddy even in a small storm into a cleaner and more natural-looking environment, with native plants and attractive stream beds.

However, fixing streams without addressing the problem that contributed to messing them up in the first place — stormwater — means that the restored stream itself is still at risk from a major storm and to degradation over time. Upstream issues must be addressed, but this can be challenging in heavily-developed, urban, and inner suburban areas where there is rarely enough space to add stormwater ponds and wetlands like you see further away from the city.

This image shows a stormwater pond, constructed in 1984, in Damascus in the upcounty to capture stormwater runoff from late-20th-century development. Image by Montgomery County Department of Environmental Protection.

In older urban and suburban residential areas, adding green infrastructure to the streets is the only real option to help control stormwater runoff. These projects consist of adding various kinds of rain gardens and retention areas (they’re also known as infiltration tree boxes or bioswales) next to the road or in the median. The bioswales take water out of gutters and hold it for one to two days in a series of depressions filled with rocks and gravel. They're layered with soil and native plants that can handle getting wet and dry.

In an older neighborhood built before modern stormwater management, there isn’t room to add a pond without impacting the stream, which is no longer considered legal or appropriate. Image by Montgomery County.

These bioswales often end up looking like curb bump-outs, which extend the curb and create a shorter crossing for pedestrians. This has the added benefit of making streets safer by encouraging drivers to slow down. They’re part of a Complete Green Streets program, which aims to make roads both environmentally-sustainable and friendly to all kinds of travelers.

This is a Complete Green Street in Lancaster, PA. In the foreground is a conservation landscape that offers greenery and a tree strip along the sidewalk. Across the street downhill is a bump-out at the curb that is a rain garden that catches, filters, and infiltrates water from the street. The red block paving under the cars is permeable pavers that allows water to soak directly into the ground. This was previously a high-speed, one-way street that was changed to two-way, with a bike lane and safer pedestrian crossings, and added beauty and shade to the street. Image by the author.

Montgomery County has a history of pioneering stormwater management in our region. The county’s Department of Environmental Protection (DEP), often in partnership with the Department of Transportation (DOT), began installing Green Streets in the older, downcounty neighborhoods in 2012. Some of these projects, like Sligo Park Hills, were done in collaboration with local residents and customized to address aesthetic, parking, and other concerns.

Arcola Avenue Green Street. Image by Montgomery County Department of Environmental Protection.

Forest Estates. Image by Montgomery County Department of Environmental Protection.

Montgomery County's Green Streets program is in jeapordy

DEP recognized it had an outreach problem in certain communities when some people began objecting to the rain gardens. In early 2017 it proposed a new, pilot approach in some of the most challenging neighborhoods to give residents more choices with some popular project options like permeable pavement over parking spots, even though these can be more expensive.

However, the agency never got the chance to try out their new approach. DEP conducted an internal review in late 2017 and determined that it should restructure the entire program. This included cancelling the three most controversial Green Streets and suspending the other four, with the possibility that a new private contractor could pick them up as part of a bundled project package in the future.

Watershed advocates, like my organization (Audubon Naturalist Society), have opposed this restructuring and think it’s unnecessary and misguided. We are very worried that the new approach could lead to the county dropping certain kinds of green infrastructure like these Green Streets projects, since they can be more expensive per equivalent amount of stormwater credit compared to some other options.

As of this writing, the Montgomery County Council agrees — and has restored some funding to the Green Streets budget line for the current capital budget. However, Executive Ike Leggett threatened to use a line-item veto on the remaining budget for the stormwater program because he disagreed with the Council’s decision. Vetoing the program would mean cutting millions more from a capital budget that was already cut by $243 million, delaying the County’s progress towards clean streams.

Can these projects be complicated and hard to do? Yes, but they are also worth it. The health of our streams and waterways depends on it.