When the project to construct the Silver Springs Arroyo Dam was completed in early October, a unique phase two of the project began.
While the new dam helps reduce flood risk for the area, building it resulted in loss of some natural flora. Neighbors of the project were highly engaged from the beginning of the construction project and voiced concerns about the loss, and EPWater listened.
El Paso Water hired Arcadis U.S., Inc. to develop a site vegetation restoration plan.
The goal of the project is to restore the site to native pre-construction vegetative conditions and to provide a seamless visual into the existing desert landscape.
“We knew during the design of the new dam that we were going to have to disturb a significant area of this natural arroyo, and revegetation would be a necessity,” said Project Manager Ryan Stubbs. “We typically rely on landscape architects to lead these type of restoration projects, but this time we had an ecologist step in and take the lead.”
The two-week project consisted of seeding and manually-planting 5,000 plantings of regionally-appropriate plant species, native to the arid Chihuahuan Desert.
Because the nature of the stormwater project does not allow mechanized disturbance of the soil due to engineering restrictions, all the seeding and planting was done by hand.
The plant selection was also important. Woody or deep-rooted plant species could pose a risk to the soil stability and structural integrity of the engineered levee and spillway surfaces. Therefore, only bare-root and potted plug species were used.
Some of those plants are century plant, Mexican grass tree, stool, Turpentine bush, giant hesperaloe, yucca (red, banana and soaptree), four-nerve daisy and creosote bush.
EPWater and Arcadis will monitor the area for a period of one year to ensure the revegetation is successful. The key to success can be pinpointed by evaluating seed germination, checking for survival of potted plugs, observing the natural arrival of new plants and species within the basin and through a visual inspection of the overall vegetation ground cover.
Also, to ensure the continued growth of the desert landscape, there will be regular monitoring and manual removal of invasive plant species. Invasive, non-native species can quickly decimate the restoration and could also have adverse effects to the project’s stability and structural integrity.
Gisela Dagnino, Engineering Division Manager, says EPWater will be observing the success of this process for its possible implementation on other major stormwater projects.
“We have to be mindful of the community, but also of the flora and fauna that we may disrupt. I believe our projects can be successful and beautiful without having a detrimental effect on nature.”