Resource development projects can change water flow, chemistry, or physical habitat of rivers, lakes, and other aquatic systems. Mitigation strategies can offset losses of one or more valued ecosystem components that are sensitive to the changes but they require diligent design and testing. Limnotek contributes to mitigation designs and assesses their effectiveness. Testing effectiveness is done using rigorous monitoring in layouts that facilitate statistical tests of mitigation effect. Results are used to defend a mitigation strategy or show evidence of need for alternatives.