There are all kinds of grants of there. I don't know about the state agencies you have but there are plenty of federal grants out there but the only issue is that they will have demands for how you manage the place (e.g. water control, hunting/refuge areas, levy placement, etc..). Often times agencies will want you to not only manage habitat for ducks but also shorebirds, native grasses, and birds of prey. I highly recommend setting an area of your property as a designated closed-zone/refuge for ducks that you plan to NEVER hunt. It will pay dividends to have the refuge because you will have a healthy population of local ducks that are always around and they will attract the new stupid ducks that are easy pickens.
Waitin for Greenheads.