Required mitigation of wetlands impacts is a mandatory feature of many Clean Water Act §404 permits. In Koontz v. St. Johns River Water Management District, the U.S. Supreme Court held that government agencies must show a relationship between a proposed permit condition and the adverse environmental effects that the condition proposes to mitigate. The permit condition also must be proportional to the scope of the proposed project regardless of whether the permit condition is a demand for money or property. Current permitting practices tend to identify the nexus between the permit conditions and to be proportional. Still, to be prepared for future lawsuits by property owners asserting their private property rights under the Takings Clause of the Fifth Amendment, existing compensatory mitigation guidelines should be amended to set forth more strict guidelines on how mitigation requirements are quantified and how mitigation is measured against the proposed development’s impact.