I’ve searched around and mostly seen people create custom radiator builds attached to their water supply, but that’s beyond my skill level and I’m not sure if linking it directly to the water supply via piping would violate the lease or not. Are there any solutions a bit more DIY that I could take advantage of?
Start a car detailing business. Use the water to wash the cars.
Use the money from new, low-overhead business to do anything you want.