Colusa Basin Watershed Integrated Resources Management Act

Colusa Basin Watershed Integrated Resources Management Act - Authorizes the Secretary of the Interior to provide financial assistance for use by the Colusa Basin Drainage District, California, or by local agencies for planning, design, environmental compliance, and construction required to carry out eligible projects in the Colusa Basin Watershed to: (1) reduce the risk of damage to urban and agricultural areas from flooding or the discharge of drainage water or tailwater; (2) assist in groundwater recharge efforts to alleviate overdraft and land subsidence; or (3) construct, restore or preserve wetland and riparian habitat; and (4) capture surface or stormwater for conservation, conjunctive use, and increased water supplies. Requires the Secretary to ensure that funded projects are not inconsistent with watershed protection and environmental restoration efforts being carried out under the Central Valley Project Improvement Act or the CALFED Bay-Delta Program. Directs the Secretary to require that the District and cooperating non-Federal agencies or organizations pay: (1) 25 percent of project construction costs; (2) 100 percent of project operation, maintenance, and replacement and rehabilitation costs; and (3) 35 percent of planning, design, and environmental compliance activity costs.

Permits funds appropriated pursuant to this Act to be made available to fund 65 percent of costs incurred for planning, design, and environmental compliance activities by the District or by local agencies in accordance with agreements with the Secretary, under which the District or local agency is required to pay the non-Federal share of construction costs and which governs the funding of planning, design, and compliance activities costs.

Authorizes specified expenditures within existing budget authority to carry out this Act.