I actually had a similar idea. The project that I was thinking of mentioning was one that is trying to the save largest inland lake in Ohio. It's a dying lake thanks to algae and farm run-off, and it's killing the local economy. It's going to cost a lot of money to fix the lake - millions of dollars.
I'm just curious what the donations go towards or what solution is proposed? It seems the problem is with runoff from high nitrogen chemical fertilizers causing algae blooms? In water ways I'm familiar with that had algae blooms, a public private partnership focusing attention on existing regulations managed to get waste products from livestock manged better and dramatically reduced the blooms and the harm that came from them. It didn't need a lot of money, it just needed people to pay attention to the right things, and some agri business to put out some costs to change to comply with existing laws. Obviously that isn't true everywhere, I'm just wondering what your situation is - is it to stop ongoing problems or to get it out?