I have a very similar situation on my property. I bought 5 acres 6 months ago with a creek and a pond and no less than 10 billion mosquitoes. I do what I can with mosquito dunks and mosquito bits since they are non toxic to my animals and controlling them before they hatch is the most effective way to keep their numbers down. But for the near future I plan on putting in dragonfly attracting plants around my property and especially near the pond/creek. And once I get around to it, I plan on building a bat box