I live near one of the poorest cities in the US. The city's local district needs about $1.5B in facility upgrades to make the buildings fit for kids: everything from HVAC, to lighting and plumbing, to structural issues, to new roofs. Rats and insect infestations are a problem in some of the worst conditions. It's not uncommon for schools to be abruptly closed for facility reasons (no heat, broken water main, etc.). It's unconscionable that kids have to go to school in many of the buildings.

In my state, facilities can only be funded through levying a local millage to service a bond. However, because of incentives to corporations to relocate back to the city, the tax base is minimal. City taxes are already the highest in the state, so they do not have the capacity to raise funds through a bond proposal.

So if I were to win ~$500M lump sum, I'd donate half to the district to make urgently needed facility upgrades. It won't completely solve the problem, but it's a start. It would lower my tax burden considerably and I'd still have more than enough to live a life of luxury for the rest of my days.