The board of directors may sell property or assets of the district not needed for district use nor essential to its operation from time to time as it directs and upon such notice as it designates, and shall cause the proceeds thereof to be placed in the bond fund or United States contract fund of the district. If the district has no bonded or United States contract indebtedness, then the proceeds shall be placed in the general fund.
C.R.S. § 37-42-137