(a) A district may borrow for any legal purpose from the United States or from any banking institution or other source not more than $250,000 to meet temporary needs, and may issue notes or other short term obligations other than bonds which will mature in not more than 10 years from their date and may pledge any securities owned by them or their surplus revenues.
(b) A district, in the acquisition of land necessary for the development of its ports and waterways both industrial and otherwise, may execute purchase money notes securing same with liens on the land being acquired or with a pledge of surplus revenue, or with both. The notes may bear interest at the rate determined by the commission.