At the discretion of the board of directors of the district, any bonds provided for in Section 55-19-17 may be further secured by a trust agreement between the board of directors and a corporate trustee, which may be any trust company or bank having powers of a trust company within or without the state. Any such trust agreement or any resolution providing for the issuance of such bonds may contain such provisions for protecting and enforcing the right and remedies of the bondholders as are reasonable and proper and not in violation of law. The trust agreement may contain provision for the issuance of additional bonds for any of the purposes authorized by this chapter which shall be secured by the revenues pledged thereunder for such bonds to the extent provided therein. The trust agreement may include provisions to the effect that if there is any default in the payment of principal or interest on any of said bonds, any court having jurisdiction of the action may appoint a receiver to administer the properties and facilities of the district, including the authority to sell or make contracts for the sale of any services, facilities or commodities of the district or to renew such contracts, subject to the approval of the court appointing said receiver; and with the power to provide for the payment of such bonds outstanding, or the payment of operating expenses, and to apply the income and revenues to the payment of said bonds and interest thereon in accordance with the resolution of the board of directors authorizing the issuance of such bonds and said trust agreement. The fee for the services of any corporate trustee shall not exceed the normal charges for acting as paying agent plus any additional amount or amounts allowed by the court as the reasonable value of services rendered by the corporate trustee upon default in the payment of principal and interest on the bonds.