The City and County of San Francisco, the Modesto Irrigation District, and the Turlock Irrigation District shall give assurances satisfactory to the Secretary of War that the local cooperation required by Section 3 of the act of Congress approved December 22, 1944 (Public, Numbered 534, Seventy-eighth Congress, Second Session), will be furnished by the City and County of San Francisco, the Modesto Irrigation District, and the Turlock Irrigation District in connection with the flood control projects within the watershed of the Tuolumne River, adopted and authorized in Section 12651, except insofar as the projects include channel improvement works and levees.