Depends on how and where you plant them. Bald cypress use as much water as they can get. When first planted, after the last spring freeze, they need lots of water to establish good roots. They can withstand several months of flooding, but don't mind some dry time, too. That's why the do so well in swamps. Swamps rise and fall. Cypress trees like that lifestyle. We have some planted in the town square of Whitesboro, Texas, in the middle of downtown. City workers water them from time to time, but they grow in a small patch of dirt in the median of Main Street. So, they can do without as much water as they mature, but grow much better with plentiful water. If you plant them in the upper reaches of your pond, they will consume more water when the pond is full, less as the level drops. I would choose them.

Teach a man to grow fish...
He can teach to catch fish...