Cosumnes and Mokelumne Rivers Floodplain Integrated Resources Management Plan

The Cosumnes and Mokelumne Rivers Floodplain Integrated Resources Management Plan is a multi-agency effort designed to develop a management strategy that facilitates effective enhancement of floodplain conditions and functions of the lower Cosumnes and Mokelumne rivers. The project goals are:

• Develop an Integrated Resource Management Plan to guide the implementation of prioritized management actions that will effectively enhance floodplain and riparian habitats, flood management, and groundwater recharge along the lower Cosumnes and Mokelumne rivers.
• Engage stakeholders in the Plan development.
• Utilize the principles of adaptive management in Plan development and implementation.
• The development of floodplain management strategies along the Cosumnes River involves extensive floodplain modeling using FLO-2D, a 2-dimensional floodplain hydraulic model. RBI developed two FLO-2D models that provide platforms for evaluating.
• Flood management options to manage high flows and protect levees and agricultural lands on over 50 square miles of floodplain area.
• Floodplain restoration options to enhance floodplain functions that support riparian habitats on over 10 square miles of floodplain controlled by The Nature Conservancy.

RBI developed a detailed restoration management plan for the Mokelumne River, which is highly controlled by reservoirs and levees. This plan focuses on landowner-driven restoration projects and includes a landowner manual that assists landowners in understanding, designing and implementing restoration practices. The restoration plan sets out a prioritization process for assessing landowner projects and then aligning projects with potential funding sources.