The small town of Lexington, VA, has big plans for a 4-acre plot of land officials have wanted to develop since the late ’90s — but not into big houses.

In fact, some of the two-dozen homes being built on the lots will measure just 950 square feet as the development’s partners aim to provide much-needed housing for low-income residents.

The big idea is in the project’s other and equal goal: to demonstrate the best in low-impact development and stormwater management in an area of the watershed that’s not often the focus of such efforts.

Through a partnership with several agencies, each of the homes will have a rain barrel that allows residents to collect and reuse the water, and each lot will have a rain garden that helps filter and clean water before it leaves the property.

These and other additions are funded in part by a $200,000 grant from the National Fish and Wildlife Foundation’s Chesapeake Bay Stewardship Fund, which recognized the significance this development could have for others throughout the watershed.

“This project is a unique example of a local government integrating environmental protection into affordable housing,” said Jake Reilly, director of Chesapeake Bay Programs at the NFWF.

He said the foundation liked the concept of helping local governments meet their water quality goals while engaging new partners in environmental projects.

Lexington’s nonprofit housing commission, called Threshold, is partnering in the project with the Rockbridge Area Habitat for Humanity, a nonprofit Christian housing organization that sees the collaboration as its foray into “green neighborhoods.” Volunteer builders and families working with Habitat to construct homes will be taught best management practices to reduce runoff in the process.

And, perhaps most importantly, residents that move into the homes will receive training on how to make the most of their stormwater-optimized abodes.

Instead of turning on the hose to wash their cars, for example, they can use the water collected in their rain barrels. They’ll learn how to trim their rain gardens to keep them effective and have the option of using permeable driveway surfaces.

“In a lot of cities, one of the biggest runoff problems is from residential yards,” said Michael Zehner, Lexington’s planning and development director, during a walk through the construction site. “Everything from the city flows eventually into the Chesapeake Bay, because it flows into the Maury River.”

There are no streams running through or next to the planned neighborhood, but the Maury River flows into the James River about a half-mile away. The road feeding into the development is on an incline, and it’s not hard to imagine the water flow that could accompany a heavy rain.

But, Zehner says, “The amount of runoff coming off of these lots is going to very minimal.”

He pointed out a “bio-retention pond” beginning to take shape at the bottom of the entryway slope. The pond is planted with native species and special soils to help filter the water, but Zehner said he’d be surprised if there’s ever much water in either of the two ponds on site.

Feeding into one of the ponds is a narrow ditch, or swale, along one side of the road. Thin slabs of concrete intersect the ditch along its length. These concrete weirs help slow the water as it flows downhill, allowing solids to settle to the bottom before the water trickles through a narrow opening in the concrete.

A curb and sidewalk are already constructed on the opposite side of the main street, which is slanted slightly toward the ditch to direct water.

Crews broke ground on the site in March 2012, and home construction is scheduled to begin in the summer.

Zehner, who is certified for Leadership in Energy & Environmental Design, or LEED, said he hasn’t seen this level of green innovation in one project over his decade in the industry. The Virginia Department of Housing and Community Development gave the city a grant to fund the extensive planning the project required. And a $700,000 federal Community Development Block Grant helped the city acquire the site.

Zehner said the innovations being implemented, when planned for on the front end of a project, don’t necessarily cost more in the end —though it’s often difficult to get so much upfront funding.

Thanks to such funding, two of the 24 houses will feature “green roofs” growing vegetation to absorb a portion of the water before it can even run into rain barrels. Zehner said constructing those roofs to withstand the weight of plants and grasses will be a challenge.

The project had requested funding for porous sidewalks as well, but Zehner said those might require too much maintenance to be practical. The porous concrete must be cleaned out at least annually to remove the dirt and sand that can collect in its holes.

Homeowners still will have the option of using porous asphalt or turf-filled pavers for their driveways.

At the site, it’s difficult to imagine two-dozen homes fitting onto the narrow lots, some of which were still being cleared and prepared last month. The homes could range in size from a 950-square-foot one-bedroom to a “tall and skinny” 2,000-square-foot home with four bedrooms.

The homes will be close together and close to the street to minimize lot sizes and encourage a sense of community.

“Everyone will have covered front porches and get to know their neighbors,” said Jeanene Campbell, Housing Counselor for the City of Lexington.

Campbell said that sustainable elements of the homes also will help residents save money running and maintaining them.

Washing a car with recycled water “helps with your monthly expenses, so you’re not getting a $100 water bill every month,” she said. “It all cycles around full circle.”

The developer for the project, Thompson’s Knoll, is advertising the neighborhood as “eco-friendly homes within your reach.”

Residents must qualify financially to live in the homes, which are intended for individuals and families with low– or moderate-incomes. A family of four making a little more than $44,000, for example, would qualify for one of the Thompson’s Knoll homes.

The City of Lexington has recognized its shortage of affordable housing for a couple of decades. A constant flow of student residents at the town’s two universities drive up rental rates in town.

The new neighborhood will be located in city limits and within walking distance of a school, the historic downtown and the two universities, which are major employers.

The NFWF’s Reilly said the project is an example that could be integrated into other cities’ efforts to build new affordable housing options while considering the environmental impact of those developments.

In their grant request, organizers of the project said they hoped it would be an example to other “headwaters communities” in the watershed that have “very few reminders, if any, that their behavior toward the local environment directly impacts the health of the Bay.”

Lexington is almost 150 miles from the Bay. But the city, like others, is aware of its impact on local waterways. Sections of the primary stream running through the city, Woods Creek, were described as impaired as a result of stormwater runoff according to a 2012 report from the Virginia Department of Environmental Quality.

The city said in its grant request that it has addressed runoff issues on public land where feasible and that the next frontier for improvement is on private and mostly residential properties such as this one.