Your local animal control, or forestry service should be able to assist you with the ducks, that is their job.
Even living in a city there should be a forestry agent that covers your area, since ducks and geese are considered wildlife it is their job to help protect the wildlife, which in your case would be to relocate them to someplace proper for their species.
The
National Audubon Society,
U.S. Fish and Wildlife Service, your local Wildlife/Forestry Conversation Dept, or any number of such places should be able and willing to help.
Our State Forestry Service has helped us many times since we bought our property 20+ years ago, when we found out we didn't have the kind of wildlife out here like there should have been they came out and spent almost a whole day walking our property with us and showed us what the problem was and how to correct it, one of their suggestions was to build a pond, so they showed us the best location, then surveyed the whole thing complete with flags marking everything, and then sent us detailed instructions and blueprints, a few years back our pond was overgrown with underwater grass and weeds, so we called them out and they told us the simple answer was to put 2 or 3 Hybrid Carp in, they would eat the weeds and grass, it took 2 of them about 4 months to clear the pond and we haven't had any problems since, when we wanted to have some timber cut they came out and showed us what and where we should cut and what we should leave, (they even went so far as to mark the trees to be cut), plus they gave us a list of local logging companies, now that we own a logging company they assist us all the time when we look at a property that someone wants cut.
You have many resources to solve this problem, all it takes is a few phone calls.