Historically, tidal marshes in Solano County were prolific sources of mosquitoes, an aggressive, migrating, day-biting species. In addition to direct abatement, water management practices have been developed by the Solano County Mosquito Abatement District (SCMAD) to prevent the production of mosquitoes in tidal marshes. The principal prevention method consists of the construction of ditches to circulate tidal water into sloughs and bays to avoid ponding. The following recommendations should be considered to reduce the mosquito production in tidal marshes.

Policies For Tidal Marsh Management

1. All marsh lands should be periodically surveyed to determine if ditches and drainage water control structures are properly placed to ensure effective drainage.

2. Ensure that all spreader ditches are constructed and maintained free and clear of debris and vegetation. Clear and retrench approximately every three years.

3. Spreader ditches should be properly connected to a slough via a main ditch or by having a flap gate, weir box or other adequate water control mechanism.

4. The drainage capacity of the drainage systems (spreader and main ditches) should take no more than 5 days to ensure full removal of water from the surface to the marsh prior to potential mosquito production.

5. To ensure the effectiveness of the drainage system and water control structures for the prevention of mosquitoes, the SCMAD will conduct surveillance after each bi-monthly high tide.

The preceding mosquito prevention criteria are intended only to offer guidance when considering the development of design options during the planning process for projects. Be advised that these practices have been found to be effective, however, once the project has been completed it is essential that conscientious maintenance and management practices be followed to help ensure the successful prevention of mosquito production.

Be further advised that under the California Health and Safety Code (Sections 2274 et. seq.) the responsibility for the cost of mosquito control may fall on the property owner.