Brad Lancaster has written several books inacluding "Rainwater Harvesting for Drylands and Beyond volumes 1 an 2." He lives in Tucson, Arizona, an area that receives 11 inches [280 mm] of annual rainfall. He has led the City of Tucson to create city-wide rainwater harvesting programs. His website is
https://www.harvestingrainwater.com/. He also has numerous videos if you search for Bread Lancaster Tucson on YouTube.
Https://www.youtube.com/watch?v=KcAMXm9zITg is a tour of his fascinating house including all of home-made systems that he designed and built that go well beyond rainwater harvesting.
