Green Infrastructure Impact Volunteering Project

November and December 2018

On a sunny winter day in El Paso, Texas, the Creosote Collaborative team partnered with local rainwater harvesting experts and volunteers in a historic neighborhood to transform a parkway from a barren flat surface to one that could hold approximately 1,000 gallons of rainwater. This project is helping to “green the grey” — this passive rainwater harvesting project is part of a larger green infrastructure (GI) strategy to manage water where it falls while addressing other resilience challenges such as extreme heat and flooding.  GI can provide multiple benefits such as reducing standing water, providing habitat for wildlife, and improving air quality.

This specific project involved a three-hour classroom session to better understand water budgets, bioswale sizing and design, and watersheds. The attendees then volunteered for 5+ hours the following day to help the Creosote Collaborative and High Desert Native Plants team dig and plant in the parkway of a historic home in the Sunset Heights historic district. First, the volunteers analyzed the watershed onsite to better understand how rainwater would flow near the site and where the curb cut should be made. Then, the volunteers grabbed shovels and begin to dig approximately 18 inches down. While some volunteers were digging, other volunteers hauled wheelbarrow after wheelbarrow of dirt and mulch to the backyard or the parkway and arranged rocks near the curb cut for the spillway.

Once the digging was finished and the spillway was created, the volunteers learned how to properly plant and prune trees to promote long-term health and success. Two Palo Verdes and eight native shrubs were planted to absorb water, control erosion, provide shade and habitat, filter pollutants out of the stormwater, and increase property value. Careful calculations were taken to ensure our basins could hold enough rainwater to sustain the trees and plants in the parkway. The combined estimated capacity of the basins is about 1,000 gallons. Given the size of the street watershed, the basins can hold about a half an inch of rain that falls on the street.  Based on El Paso rain records, it is likely that these basins (in this very small parkway) will fill and overflow at least five times a year, which shows that even small bioswales can provide plenty of water to support vegetation in our parkways without supplemental potable-water irrigation. The added bonus is that we are pulling water off the street, which long-term can lead to less standing water, reduced stormwater runoff velocities, reduced numbers of potholes, and fewer dollars spent on vector control.

This project served as a teaching opportunity and will continue to be a stop on Creosote’s GI Tour to encourage homeowners, City officials, and developers to incorporate green infrastructure into their designs. These small steps help build our resilience as a community and support sustainable practices.