Cal. Pub. Util. Code § 29171

Coupon bonds may be issued in denominations of one thousand dollars ($1,000), or multiples thereof, as the district may determine. Coupon bonds of different denominations shall be exchangeable for coupon bonds of other denominations or for registered bonds on terms and conditions as the district may determine, including provisions for the authentication of any bonds issued upon the exchange by the registration agent or other agents appointed by the district for that purpose.