The Concrete Plant site is located downstream of Westchester Ave in Reach 1 on the west side of the Estuary Section of the river. At Concrete Plant, NRG and community partners installed salt marsh vegetation along the north shore. The Bronx River Alliance is continuing plant installation efforts there today. At the south end of the Cement plant, a further section of salt marsh vegetation was installed with the reconstruction of the Park.
The Concrete Plant restoration started when NRG received a 131,000$ grant from the National Oceanic and Atmospheric Administration (NOAA) through funding secured by Congressmember Jose E. Sérrano. The primary goals of this project were to establish a salt marsh/brackish water planting in the inter-tidal zone of the Bronx River estuary to restore degraded shoreline habitat and demonstrate the potential for restoration efforts in a highly urban environment.
Before the project began, the inter-tidal area consisted of unconsolidated, silty, organic sediment zones of depths up to three feet. Other shoreline areas were underlain or bordered by large slabs of discarded concrete.
Concrete Plant pre-restoration
The wetland restoration involved several steps:
- A nursery was constructed at the Concrete Plant. In May 2001, 50 volunteers from environmental and community volunteers teamed up with NRG staff to construct over 8,000 ft2 of wetland planting beds.
- Salt marsh plants were inserted into mattresses of coir fabric. Spartina alterniflora made up 70% of total plantings because of its ability to colonize the inter-tidal zone and initiate salt marsh development. Other plants included Olney three-square (Scirpus americanus), common three-square (Scirpus pugens), saltmeadow bulrush (Scirpus robustus), big cordgrass (Spartina cynosuroides), and narrow-leaved cattail (Typha angustifolia).
- Plants grew in standing water for 6 to 8 weeks After 6-8 weeks, the plugs establish a dense root mat and can be transported to the planting site.
- Mats were carried to the site and secured using 6-inch metal staples and anchored with loose rock where under-lying concrete made stapling impossible.
Creating Spartina mats
Phase I. In addition to the wetlands, adjacent uplands were rehabilitated. In October 2001, steep upland slopes were re-graded and a cellular containment system (GeoWeb) was installed. In May 2002, volunteers helped plant the slopes with native warm season bunch grasses, shrubs, and herbaceous plants.
Phase II: Building on success from first round of restoration, NRG received an additional $289,000 NOAA grant (again, from funding secured by Congressmember Sérrano) for expanded upland work.
Monitoring : In 2002 and 2003 at salt marsh plots included measurement of stem density and height, percent cover of vegetation, number of flowering stems and presence of fiddler crabs and ribbed mussels. Plot 1 is at lowest elevation of marsh installation, plot 3 is at highest elevation. In 2000, stem density was zero; in 2001 stem density based on planting density and average number of shoots/plug increased dramatically. Local environmental education groups monitored water quality, fish populations, feeding and breeding birds, and plant survival.
The Bronx River Alliance, Youth Ministries for Peace and Justice, New York City Environmental Justice Alliance, Sustainable South Bronx, The Point Community Development Center, NYC Urban Park Rangers - Parks Conservation Crew, New York Restoration Project, The GAIA Institute, Rocking the Boat, Fanny Lou Hamer Freedom High School, Wave Hill Forest, and The Bronx Helpers.