Depave at Calvary UMC

Project Date: September - December 2024

Location: Nashville, TN

Waterway improved: Sugartree Creek

Restoration methods: Depaving, native tree planting

Protecting Sugartree Creek

In the fall of 2024, the Cumberland River Compact removed 6,000 square feet of underutilized asphalt from the parking lot of Calvary United Methodist Church (UMC) in the Nashville neighborhood of Green Hills. According to Calvary UMC’s facilities manager, David Low, only about a third of the parking lot is typically needed to accommodate the church’s congregation. Therefore, to save on parking lot maintenance costs and create a new green space for visitors to enjoy, Calvary elected to depave a portion of the parking lot and plant it with native trees.

The Compact’s Field Team removed the pavement, then restored the earth beneath by adding leaf compost and additional soil. When this work was complete, the area was planted with native trees by Cumberland River Compact volunteers.

ENVISIONING A GREEN SPACE

Calvary UMC sits on six acres in the Green Hills neighborhood of Nashville. Before the depave project, its parking lot accommodated about 700 people. The church’s Facilities Manager, David Low, informed the Compact’s Urban Waters team that the majority of the lot frequently went unused – especially the eastern edge, which was designated for bus parking and had fallen into a state of disrepair due to stormwater runoff. Low, a native Nashvillian with a background in forestry, championed the depaving of a portion of the parking. Not only would depaving reduce maintenance costs for the parking lot, but it would also add new green space for the congregation to enjoy. Under David’s stewardship, 51 native trees had already been planted on the church grounds through the Root Nashville campaign.

Caring for the natural world holds an essential place in David’s faith. He believes that people have a responsibility to steward the land in a way that will protect it for future generations. “I think we have to consider the kids, the grandkids, and the kids after that,” David says. “Paving this whole parking lot was the best decision at the time…but you know, it’s ok for that to change.”

The proposed depave site, located on the parking lot’s downhill edge, was strategically chosen because it was prone to degradation due to a high volume of stormwater runoff from the uphill portion of the parking lot. Planting new trees here would also absorb and filter stormwater before it runs off the parking lot and eventually into nearby Sugartree Creek.

An open parking lot. — The proposed project area before depaving.

The unused space in the parking lot represented an immense opportunity. Rather than an eyesore that generates hundreds of gallons of stormwater runoff, the church community imagined an oasis of urban trees. Despite the size of the church, there is a deficit in green spaces on the grounds; a new, robust tree canopy could signal a new beginning for the stewardship of the land the church occupies.

ASPHALT REMOVAL

This project was the first depave project to be completed entirely by Cumberland River Compact staff, rather than volunteers, marking a new era for the depave initiative in which the Compact can accomplish large projects much more efficiently. A typical depave project only takes two weeks from groundbreaking to tree planting.

Before removing asphalt, the Compact Field Team conducted a site test by removing a cross-section of the parking lot to gauge the asphalt’s depth and density. Next, a wet saw was used to slice the asphalt into small sections, which could be lifted up and removed with an excavator. Dump trucks then removed the broken-up asphalt from the property.

Two men with a sprayer and saw are cutting into the pavement of a parking lot. — Compact staff conducts a preliminary test cut to investigate the profile of the subgrade buried beneath the pavement.

An excavator tears up asphalt with a steepled church in the background. — Compact staff uses an excavator to carefully remove the asphalt.

NATIVE PLANTS AND TREES TO IMPROVE WATER QUALITY

To undo years’ worth of soil compaction and degradation in the newly depaved area, the team then performed “scoop and dump” soil remediation on the site: First, they spread a layer of leaf compost. Then, using an excavator, they scooped up the compost and soil underneath and dropped it back down, mixing everything up. This process improves the soil structure and promotes greater stormwater infiltration, ensuring it will be hospitable to young trees. On top, a layer of a special soil mixture was added to help filter pollutants from stormwater, retain moisture, and support healthy vegetation.

“Scoop and dump” soil remediation is a method of rehabilitating soil to enhance soil health and structure before tree planting takes place.

The depave site, fully prepped for planting.

As a final treatment, the soil was seeded with river oats (a native grass that thrives in moist environments) as ground cover throughout the project area to help stabilize the soil. Afterwards, the seed and straw were covered by erosion control matting to help retain the soil while tree and grass roots became established.

In December 2024, sixteen 1” caliper native trees were planted, including crabapples, hawthorn, yellowwood, and sweetbay magnolia. These trees (like many others currently thriving at Calvary UMC) were provided by the Root Nashville campaign, which the Compact operates: they’ll count toward the campaign’s goal of planting 500,000 trees in Davidson County by 2050.

River oats begin to grow through the biodegradable matting used to stabilize the newly uncovered soil at Calvary UMC in spring 2025. Native trees planted in the new green space begin to leaf out for the first time in their new home.

Depaving even a modest part of a large paved area can have outsized benefits for water quality, biodiversity, and community well-being. Where an underutilized swath of cracked asphalt once was, trees will now provide refuge for people and wildlife alike. The Calvary UMC congregation will now have a lush, shaded area to enjoy. Meanwhile, these trees will also provide nectar for beneficial pollinators such as bees and butterflies, whose habitats are threatened by urban development.

Trees are absorbent powerhouses that play a critical role in managing urban water cycles. Rather than letting rainfall become run-off, these new trees at Calvary UMC will capture and recycle rainwater through natural processes like evapotranspiration.

Calvary’s depave project will also affect the surrounding community by diverting over 1,200,000 gallons of stormwater runoff annually that would otherwise end up in nearby parking lots, streets, and yards. This project can help mitigate the frequency of problems like potholes, flash flooding, and water damage to businesses and homes. Fish and birds who rely on the nearby Sugartree creek for habitat and hydration will be healthier, and (in the case of Nashville, where drinking water comes from the Cumberland) the source of our drinking water will become cleaner.

Over time, the impact of this new green space will grow alongside the trees and continue to benefit Calvary UMC (and Green Hills at large) with lowered maintenance costs, beautiful outdoor space, naturally enhanced water quality, and critical biodiversity. Compact staff will return to the site as needed to water trees and monitor plant growth in the coming years, ensuring the project’s enduring success.