If you are a developer and build large multifamily homes or commercial structures you can develop large rainwater harvesting systems and add pumps, purification systems or filters as needed. These can then be used for building and grounds maintenance, tenants, emergency backup, firefighting etc.
https://hell.twtr.plus/media/47/59/62/475962b4dec931a75a3e9f588b9ba7f73ff330007a7201ab393b2a524f9bdf37.file
https://hell.twtr.plus/media/47/59/62/475962b4dec931a75a3e9f588b9ba7f73ff330007a7201ab393b2a524f9bdf37.file