Four Mile Run Restoration Project & Trail Detour
Four Mile Run Construction Contract Approved
The Arlington County Board approved a construction contract on June 18th for $2.9 million to restore the lower section of Four Mile Run stream. This project is the first phase of the Four Mile Run Restoration Master plan, approved in 2006, which envisions the restoration of the Four Mile Run corridor as a place along which Arlington and Alexandria residents can gather, recreate, and celebrate a shared waterfront legacy.
Treatment of invasive plants along the stream bank in Arlington will begin in September, and construction will begin in November. Construction will last approximately through Fall, 2017.
The project location is along the Arlington side of Four Mile Run, extending from Mt. Vernon Avenue and Route 1. The work in the stream will include naturalization of the stream bank and construction of living shoreline features along the edge of the stream. Living shorelines are a more environmentally sensitive way to protect stream banks and coastal areas, with wetland plantings behind small stone breakwaters. They provide numerous benefits including reducing erosion along the bank, improving water quality by capturing sediment and utilizing nutrients, and providing habitat for fish and waterfowl. The existing stone riprap that currently covers the stream banks will be removed and replaced with native vegetation that will improve the habitat quality and aesthetics of the stream channel. Some of the stone will also be reused to create the living shoreline features.
The project meets Corps of Engineers requirements to maintain flood protection, improves pedestrian access to the waterway, and improves aquatic and riparian habitat. Alexandria recently completed a wetland restoration project across the stream as part of the Four Mile Run Restoration Master Plan partnership.
The existing asphalt trail adjacent to Four Mile Run will be closed during construction, and a detour will be in place on the Alexandria trail (PDF, 3.6 MB). As part of the construction, the Arlington trail will be completely rebuilt to current standards, including a new sub-base and asphalt surface. Improved trail railings and a new observation platform will also be installed. The detour has been developed in coordination with the City of Alexandria, and will be communicated to the public with multiple forms of advance notice as well as trail signage.