N.H. Rev. Stat. Ann. § 12-G:23

Any debt service fund, construction fund, debt service reserve fund, or other fund established in connection with the issuance of bonds pursuant to RSA 12-G:17-28 shall be kept separate from other moneys of the authority. The moneys deposited in any such funds, together with the income derived from any investments held as part of such funds, shall be expended without further authorization or appropriation as provided for in the security document establishing such funds.