N.J,
I wouldn't be discouraged at all either. I have the exact same setup. I live at the end of a cul de sac and on a corner. The streets from both sides have several storm sewers that eventually drain into the pond. I had issues where the street drain had to flow aways over a rock lined ditch before finally getting into the pond. To control erosion I did end up adding more large plastic culvert sections, but it sounds like yours is covered pipe all the way till it comes in to your pond.
Yes, I'm sure we get salt run off here in MI too, but so far no signs that it has hurt anything. The dilution factor from all the street runoff when all the snow starts melting and the spring rains probably takes care of that.
I do know that after no rain for a while and then we get a heavy summer thunderstorm the water has a slight sheen on it as if some road petroleum products have washed in. I can't control that and I try not to worry about it. Our streets aren't that busy and fortunately around here no one parks on the street.
What I like about my situation is that right about when I'm ready to fire up my house well and and run it for days to bring the water up in the spring or summer, we'll get a heavy rain and I'll have a hundred thousand gallons of water in my pond in about 20 minutes. It does carry a little silt with it so I get a plume at the discharge and some sediment may build up there but to me it is a worthwhile tradeoff to have free filling several times a year.
I go around and be sure the grates are kept clear of leaves in the fall. When there was construction in the neighborhood last year I made sure they put silt traps on the storm sewer grates (and they are still there!)
You may get more silting in and for starters you may want to start out by seeing if an excavator can redig your sides (as far as arm can reach) to give you another decade of time for silt to accumulate again.
Lots of good ideas on this forum for building natural silt traps like a series of small ponds filled with vegetation in line before your pond.
Enjoy, send more pictures, and I think you will love it.
If you have questions, let us know!