In FMZ 17 the Otonabee River is a sanctuary from Lock 19 in Peterborough to Bensfort Bridge until the 3rd Saturday in May. There are several tributaries along that stretch of river that are open to angling all year for panfish and coarse fish, as well as game fish when their respective seasons open. Having said that, I have no idea how close to the main river you could get before the law deems you too close, especially at this time of year when the mouths are flooded.