Land Acquisition and Natural Resource Management in a Coastal Farming Community - Watsonville Slough Farms
The Watsonville Slough complex sits along the California coast, between Santa Cruz and Monterey. The system is the largest freshwater coastal wetland in central California, and encompasses approximately 800 acres of wetlands, marsh, grasslands, riparian woodlands and farmland.
This is a special place. Only 2% of the entire world shares the Mediterranean climate that occurs here. The cool winters and rainless summers are paradise for farmers and wildlife alike. Migratory waterfowl and over-wintering raptors seek shelter in the Watsonville Slough ecosystem, and at least a dozen state and federal species of concern are found here, including the federally-threatened California red-legged frog. Yet, amongst the wildlife is farmland. Fruits and vegetables thrive in this climate, which is neither too cold in the winter nor too hot in the summer.
The Land Trust of Santa Cruz County’s Watsonville Slough Farms property encompasses approximately 500 acres of farmland and wild wetlands, marshes, grasslands and riparian woodlands in the heart of the larger Watsonville Slough complex. The slough system is surrounded by farmland and development, and its proximity to the coast leaves it at risk of habitat loss through sea level rise and saltwater intrusion.
Our challenge and goal is to balance these competing values — farmland and wildlife — while maintaining resilience within the ecosystem.
Value of the land and habitat
The Watsonville Slough complex comprises five tributaries — the Hanson, Harkins, Struve, Watsonville and West Struve Sloughs — and is the largest and most significant wetland habitat between Pescadero Marsh, in San Mateo County, and Elkhorn Slough, in Monterey County. It is the largest remaining freshwater coastal wetland on the central California coast, and encompasses approximately 800 acres of wetlands, marsh and grasslands.
Located along the Pacific flyway, the Watsonville Slough system provides critical habitat for migratory waterfowl and over-wintering raptors. The system supports several species of federal and state concern, including the California red-legged frog — listed as threatened on the Endangered Species List — the recently delisted brown pelican, and at least 10 additional bird species that are considered of special conservation concern by the state of California.
Conservation concerns within the Watsonville Slough complex include:
- A lack of healthy, intact grasslands and riparian transitional habitat adjacent to the wetlands and between the wetlands and uplands.
- Diminished structural complexity in the wetlands.
- Invasive plants and animals — western hemlock, bullfrogs, carp, etc — had established themselves in the riparian, transitional and grassland habitats.
- Saltwater intrusion due to over-withdrawal of groundwater in the region.
Current protection status and management plan
As of February 2013, Watsonville Slough Farms protects more than half of the entire Watsonville Slough complex, and links additional wetlands that were already protected by state and federal agencies. The property includes wetlands, grassland and riparian woodlands, as well as productive farmland. A management plan for the property was finalized in the summer of 2012.
Management plan priorities include the immediate and long-term restoration and protection of habitat and biodiversity, as well as the maintenance of ecosystem resilience. The Land Trust of Santa Cruz is also working to implement more than 100 farm management practices on the conserved farmland, which encompasses approximately 180 acres. These changes will protect the water quality and health of the Watsonville Slough complex and the neighboring Monterey Bay. For example, changes in irrigation practices will help address and hopefully reduce the rate of saltwater intrusion due to excessive groundwater withdrawal throughout the region.
The protected farmland is certified organic, and remains productive. Approximately 120 acres are planted in leafy greens, producing 10 million servings each year. Another 60 acres are planted with strawberries.
Process of achieving protection and resilience to climate change
The property that would become Watsonville Slough Farms was initially identified as a conservation priority in the 2003 regional plan for Santa Cruz County. The planning process formally began in May 2009, when the Land Trust of Santa Cruz County received necessary funding from the Gordon and Betty Moore Foundation. The conservation blueprint was finalized in May 2011, and the management plan was completed in August 2012.
The project was guided by a technical advisory committee, with representation from several local, state and federal agencies, as well as local growers. The Land Trust of Santa Cruz County initiated the planning process for the conservation blueprint, and collaborated with partner organizations to protect the Watsonville Slough Farms property and develop its management plan. Support was also provided by contractors during the planning and acquisition process.
GIS technology was used to identify steep slopes, north-facing slopes and riparian areas.
Stakeholders and local concerned citizens were kept informed through periodic mailers, web bulletins, member walks and other events designed to engage the local community. Additional events, field trips and agricultural workshops were organized by partner organizations.
Climate change and sea level rise is a concern for the property. According to a vulnerability assessment done for the nearby Elkhorn Slough, low-lying portions of the Watsonville Slough Farms property could be transformed to estuary as sea level rises. Sea level rise will also exacerbate the issue of saltwater intrusion, which is already a problem within the region.
A 2012 assessment of climate vulnerability also determined that wetland species of California’s birds are most vulnerable to climate change impacts.
The project implements a variety of recommendations from the California Climate Adaptation Strategy for Biodiversity and Habitat, such as restoring aquatic habitat and setting aside reserves.
Plans for the future
Long-term goals include the preservation of biodiversity, ecosystem resilience and farmland productivity.
In an effort to further water resource protection in the region, the Land Trust of Santa Cruz County is partnering with a number of nearby growers to implement an innovative water monitoring program. The system relies on in-ground sensors, which collect and report soil moisture data to a central relay tower on the Watsonville Slough Farms property. This project will provide vital data about soil moisture levels in a region that is suffering from a diminishing water table and accompanying saltwater intrusion.
The management plan includes monitoring priorities and broad metrics for measuring success, such as the number of acres in production in any one year. Additional metrics for measuring success continue to be identified.
Ongoing partner research includes:
- Monitoring of habitat conversion in wetland communities.
- Ground-truth predictions of increasing freshwater tidal reach.
- Species specific projects focusing on black bear, swallow-tailed kites, red cockaded woodpeckers and bobwhite quail.
All work related to climate change is expected to be ongoing.
Key partners include the USFWS Coastal Program and Partners for Fish and Wildlife Program, and the State Coastal Conservancy. Funding was provided by the Gordon and Betty Moore Foundation.
- Diversified financial support is a great help. This project received financial support from community and foundation donations, proceeds from working lands and forests, and funding from government grants. This diversified approach allowed for financial security even as funds from individual sources waxed and waned.
- Partnerships are a key to success.
- Detailed priority lists — with associated budget numbers — facilitate the creation of a realistic implementation strategy. By considering budget simultaneously with priority, it was easier to narrow the list to the most essential tasks.