California officials are poised to seize control over a major arena of federal regulation in response to Trump administration rollbacks: the management and protection of wetlands. Wetlands are vital features on the landscape. Basically low spots in a watershed, when they fill with water they provide important habitat for birds, fish and other species. Wetlands also help control floods and recharge groundwater, and they filter the water we drink. On the other hand, being generally flat and maligned as “swamps,” they are popular places to pave and build.