El Polin Spring Site Development and Habitat Improvements

For the Presidio Trust

Campbell Grading, Inc., successfully restored much of the ecosystem of El Polin Spring and showcased the archeology of this important historical site. El Polin Spring is part of Tennessee Hollow, the Presidio’s largest watershed. Fresh water flows through the site, attracting numerous species of birds and other wildlife.

We demolished and removed the asphalt El Polin Loop Road that was blocking freshwater seepage from the hillside above the spring and replaced it with boardwalk and Park Tread®-surfaced trail.

Project landscape architect John Northmore Roberts & Associates strategically designed an elevated boardwalk that allowed the seepages and spring waters to flow into the central channel within the loop.

We daylighted 300 feet of the abundant spring that had flowed in underground pipes and culverts for decades and channeled the water into a series of four seasonal wetland ponds. We restored a cobble swale built by the Works Progress Administration and used it to allow the water to continue down the site and through the wetland ponds. We cleaned existing cobbles and reused them on the swale, supplementing them with only a few new cobbles.

We also created a picnic area with barbecue pits and new benches.

Archeologists had discovered an old stone foundation believed to have been that of the adobe house of Marcos Briones, a colonial soldier and widower who lived there with his three daughters in the early 1800s. The foundation was reburied to protect it for future research. We placed gabion baskets and stones in a square pattern above it to represent the old foundation to site visitors.