Based in Boulder, Colorado, Paul Zilis has had careers as a water attorney, a stream biologist, and a musician. His water law practice has focused on securing clean, renewable water for municipalities and counties throughout Colorado. He has specialized in formulating conservation plans and renewable-water projects to minimize losses and maximize the reasonable use of the West's shrinking water resources. He has appeared before the Colorado Supreme Court many times and has received numerous awards, most recently (2023) being named a pre-eminent attorney in Colorado with the highest possible rating in both legal ability and ethical standards.

Paul is now also working with tribes in several New Mexico pueblos to protect and develop their Federal reserved water rights, which have been unavailable for many decades.

Paul is also the founder of Zed Farms, which partners with food banks in Colorado to supply fresh produce to the food-insecure. Zed Farms is formulating a workable model that can be replicated anywhere, to economically utilize efficient drip irrigation systems and passive geothermal energy for heating and cooling of hoop houses year-round on a reasonable scale.