Colo. Rev. Stat. § 37-48-111
The board of directors of said district may invest any surplus funds of the district, including any amounts in the construction fund not needed for immediate use to pay the cost of construction of any project in any one of the subdistricts or to pay bonds or coupons or to meet current expenses, in securities meeting the investment requirements established in part 6 of article 75 of title 24, C.R.S. The board of directors of said district may require any funds of the district, or of any subdistrict, to be deposited with such depository or bank as may be designated by the board and likewise has authority to require the treasurer of the district to take from such depository a bond with corporate surety to insure payment of any such deposit, or to require such depository to insure payment of any such deposit, or to require such depository to pledge securities of the same kind as those in which the district is authorized to invest its funds to insure payment of any such deposit.
C.R.S. § 37-48-111