The California Department of Water Resources - Delta Suisun Marsh Office has offered an intriguing solution to the California Delta's fragile condition: plant rice.
The Rice Farming Solution
For over 100 years, as the West Delta islands have been reclaimed and farmed, the land (which is primarily made up of peat) has been subsiding. In several places within the West Delta, land has subsided over 25 feet and is continuing to subside at rates of approximately 0.5 to 1 inch per year. As the land subsides, more and more hydraulic pressure is exerted on the levees increasing the risk for levee failure. Millions of dollars are spent every year on maintaining these levee systems to insure the islands are not lost by flooding waters. Nowhere is this protection more important than in the West Delta where islands are used to hold back salty water from the San Francisco Bay, San Pablo Bay, and Suisun Marsh from the relatively clean waters of the San Joaquin and Sacramento Rivers.
This “Cork in the Bottle” ensures the quality of water that is paramount for not only human consumption, irrigation, and industrial uses but also the sustainability of many wildlife species within the Delta.
The Department of Water Resources (Department) has participated in studies that show decaying plant matter under certain conditions may not only eliminate the continued subsidence that is occurring, but also accrete plant mass and add land volume.
As part of the photosynthetic process, plants convert atmospheric carbon (CO2) into plant mass, thus fixing carbon and reducing greenhouse gasses. The Department would like to develop project(s) to demonstrate the potential for subsidence reversal and its subsequent benefits.
Rice farming has the potential to provide the Delta ecosystem with the ability to stop and possibly reverse subsidence as well as store carbon as organic matter, while providing local human populations with a potential economic benefit through commercial aspects of farming and carbon credit trading. Generating quantifiable research results that connect rice cultivation with subsidence reversal is a central part of this effort.
However, as a result of the decay of plant matter and other land management activities associated with rice farming, there is a need to develop management practices that eliminate adverse water and air quality impacts. As a result, these land management activities must be analyzed to ensure water and air quality are not adversely impacted and overall potential risk must be considered before these practices are encouraged Delta-wide. An important part of this project will seek to quantify water quality, sediment, nutrient, pollutant loads and fluxes, with a special focus on methyl mercury. Best management practices that foster subsidence reduction and minimize adverse environmental impacts such as increased nutrient and pollutant exports from rice growing areas will be implemented and assessed.
Funding for the Subsidence Solution
The DWR says it will pay for a rice cultivation project to test the theory
The project will also measure water and air quality impacts as well as the overall potential risk from the increased rice farming. The minimum size of the rice growing plot is 300 acres and the required average depth of peat underlying the site is seven feet.
The DWR says it plans to have one funding recipient for a multi-year project lasting up to eight years. with funding as much as $8 million for this multi year effort.
Local public agencies meeting the criteria as defined in California Water Code Section 12311(a) may apply for funds. Applications for funding will be accepted from reclamation districts meeting the aforementioned criteria. These reclamation districts are encouraged to associate with research entities that may include but are not limited to: academic institutions; federal, state, and local agencies; private consulting firms and entities that are qualified to complete the activities associated with this project. There is also a farming component to this project, which may require partnership with a grower that has rice farming experience.The minimum size of the rice growing farm plot is 300 acres and the required average depth of peat underlying the study site is 7 feet. Please provide location details in the proposal that ensures these minimum criteria are met.
1. rice cultivation/agroecology
2. subsidence reversal and soil carbon dynamics
3. water and air quality impacts/biogeochemistry
4. economy/socio-economic implications
5. management/research recommendations
If you have additional questions or need further clarifications, please contact Mr. Bryan Brock at bpbrock@water.ca.gov or (916) 651-0836. Download the report and application from the Department of Water
