The Arizona Legislature’s Republican leadership and a homebuilders group are suing the state water department over a groundwater rule for developers. The Department of Water Resources regulation permits developers to build where groundwater is the only water source – areas that are otherwise under a building moratorium instituted by Gov. Katie Hobbs. … Under the Alternative Path to Designation of Assured Water Supply rules, developers in those areas must provide additional water to offset their groundwater usage. … House Speaker Steve Montenegro calls the regulation “a 33.3% groundwater tax,” saying it threatens housing affordability.