The board of directors of the reclamation district shall have full authority to manage and conduct the business affairs of the general improvement district, to employ and appoint such agents, officers and employees as may be necessary and prescribe their duties, to establish reasonable bylaws, rules and regulations for the government and management of the affairs of the improvement district, and generally to perform any and all acts necessary to carry out the purpose of the general improvement district: PROVIDED, That no act done nor contract entered into by the district board for or in behalf of any improvement district or in behalf of any divisional district herein authorized, shall in any manner bind the reclamation district or render the same liable except as herein specifically provided, but such act or contract shall be chargeable exclusively to the lands of the improvement district or divisional district concerned.