What we do: Habitat Restoration

Invasive Plant Control

Since 2004, San Elijo Lagoon Conservancy has administered a regional invasive species control program on behalf of the Carlsbad Watershed Network (CWN). The CWN is a consortium of nine non-governmental organizations, seven cities in north-coastal San Diego County, the County of San Diego, and over 10 other governmental agencies and academia working to restore the Carlsbad Hydrologic Unit (CHU). The CHU includes watersheds that drain into the following creeks that flow into the Pacific Ocean: Loma Alta, Buena Vista, Agua Hedionda, Encinas, San Marcos, Cottonwood, and Escondido Creeks. Restoration efforts focus on controlling the most threatening invasive plant species which are arundo, tamarisk, pampas grass, perennial pepperweed, and palms. Individual landowners with invasive plant species on their property are contacted and written permission is obtained prior to initiation of any work. There are no costs or fees to the property owner associated with this project.

The main invasive non-native plant species we focus on include giant reed (Arundo donax), pampas grass (Cortaderia selloana), perennial pepperweed (Lepidium latifolium)tamarisk (Tamarix ramosissima) and palms. These plants do extensive damage to private property and natural resources. They contribute to flood damage, increase the risks associated with fire, and degrade native habitat. They also spread aggressively, potentially onto neighboring properties, making them difficult to control. The targeted plants are treated by applying herbicide to the plant. Fully licensed and insured professionals carry out the applications.

Before and after arundo removal and native vegetation regrowth along a stretch of Escondindo
Creek (Photo: SELC Archives)

Once the plants are dead, the remaining biomass is reduced on the site if possible. This reduces the chances of infestation by other non-native plant species. Extra care is taken to avoid impacting native vegetation during the biomass reduction process. If site conditions are appropriate, native plants will be planted within the treatment area with the goal of restoring habitat function. Re-vegetating the area with native shrubs and trees will greatly improve the riparian habitat that ultimately improves the quality of water entering the lagoons of the CHU, including the San Elijo Lagoon. The program was initially funded by a Watershed Protection grant from the State Water Resources Control Board. With that initial funding we treated 279 acres of invasive non-native plants throughout the CHU and identified an additional 290 acres of invasive plants to be treated with other funds. Click here to download the final report. Our invasive species data layer is available for interested GIS users. Click here to download. The continuation of the invasive species control program is essential to the health of the CHU. In 2006, the Wildlife Conservation Board granted an additional $1.5 million to the CWN for the continuation of the invasive species control program throughout the CHU. The Conservancy has also received funding from SANDAG’s Transnet EMP funds for invasive species control within the CHU.