Chesapeake Bay Restoration Act of 2009

Chesapeake Bay Restoration Act of 2009 - Amends the Federal Water Pollution Control Act to require, by January 1, 2009, that each local governmental unit within the Chesapeake Bay watershed that discharges stormwater through a storm sewer system obtain and comply with a permit for municipal or industrial stormwater discharges under such Act.

Requires such permit to include requirements to ensure that a project to develop land within that unit's jurisdiction, which affects land more than one acre in size and less than 5% covered by impervious surfaces prior to the project, is carried out in a manner that not less than the volume of the 95th percentile precipitation event (the event whose precipitation total is greater than or equal to 95% of all 24-hour storm events on an annual basis) shall infiltrate, evapotranspirate from, or be harvested and used on such site after the project is completed.

Authorizes the Administrator of the Environmental Protection Agency (EPA) to make grants to a local governmental unit with such a permit, which may be used for costs associated with: (1) complying with such permit; and (2) implementing a project designed, constructed, and maintained to meet the relevant performance standard. Prohibits a grant for costs associated with implementing a low impact development project from exceeding 75% of such costs.

Requires the Administrator, by: (1) June 1, 2010, to issue guidance regarding the implementation of practices that retain stormwater on-site through infiltration, evapotranspiration, or harvesting, to assist entities affected by the permit to meet its requirements; and (2) January 1, 2012, to coordinate with heads of other federal agencies to develop plans to maximize forest cover on government-owned land in the watershed through the preservation of existing forest cover and the development of reforestation plans for land that has previously been disturbed or developed.