Jackson Gulch Rehabilitation Act of 2009 - Directs the Secretary of the Interior, acting through the Commissioner of Reclamation: (1) to pay the federal share of the cost of carrying out the Jackson Gulch rehabilitation project in Colorado, subject to a reimbursement requirement; and (2) in preparing any studies related to the project, to use existing studies to the maximum extent possible, including engineering and resource information provided by, or at the direction of, federal, state, or local agencies and the Mancos Water Conservancy District.

Requires the Secretary to recover from the District, as reimbursable expenses, the lesser of 35% of the project's cost or $2.9 million over a 15-year period, without interest. Directs the Secretary to credit the District for any amounts it paid before this Act's enactment for engineering work and improvements.

Makes the District responsible for the operation and maintenance of any facility constructed or rehabilitated under this Act.

Shields the United States from liability for damages arising out of any act, omission, or occurrence relating to a facility rehabilitated or constructed under this Act.

Provides that an activity provided federal funding under this Act shall not be considered a supplemental or additional benefit under the reclamation laws or under the Act of August 11, 1939.