Colo. Rev. Stat. § 37-88-106
For the purpose of aiding in the construction of said ditches, canals, reservoirs, and feeders, the department of corrections is authorized to receive subscriptions and advancements of money from persons owning land along the line of said proposed ditches, canals, reservoirs, and feeders, or persons desiring the construction of the same, and to issue receipts or certificates to such persons so advancing money for the amount thereof, which receipt or certificate shall draw interest at the rate of seven percent per annum, and both principal and interest shall be payable in water to be taken from said ditches, canals, reservoirs, or feeders, under such rules and regulations as may be adopted by said department and the state engineer and approved by the governor of the state.
C.R.S. § 37-88-106