Mike,
In my area, the NRCS div of USDA is the main source of information and potential funding for water projects. They will know what and who to contact. There is a much higher interest in wetland projects (in layman's terms, 48" max water depth). 10 years ago, ponds were higher on their priority list...not so today. The interest seems to be adjusted based on decree from one state to the next. In Illinois, the NRCS offices I talked with (half dozen or so during property search) all were super accommodating at assistance and promised handling all the engineering aspects as long as it stayed below 50 Ac Ft of containment. They would not, tho, cost share the actual construction costs. Years ago, they did (word is that this may have changed recently...I have no personal experience to confirm). Once you cross the border into a neighboring state, it seems to be a new set of rules.
I must add, tho, that there are many habitat and soil conservation programs available that do provide cost share and even annual payments over a contract period. Once again, your best start is going to be with your NRCS office. In my case, our project is small...their WHIP program will be utilized (Wildife Habitat Incentive Program). My NRCS officer started the ball rolling, ultimately getting the State DNR wildlife bioligist involved. I then discovered that the DNR can and will also provide funding. My point: I started with good help from the NRCS office.
(EDIT; this is the link I use for my area of the USDA:
USDA N.E. ...good luck and don't get lost
)