The property owner or the HOA will need to establish an Operation and Maintenance (O&M) fund and assess annual fees for maintenance. Typically, fees are established by the developer prior to turning the responsibility of the pond over to the owner. After several years of operation with these set fees, it may be necessary to re-evaluate maintenance costs for the actual operation of the pond after the development is established. Maintenance costs depend on both the type and condition of the existing system. An excellent source of information about pond maintenance costs is MHFD.