The Federal Clean Water Act (and many other statutes) makes it clear that any development has to comply with a no net-loss standard when it comes to impacting wetlands and other natural resources. Project proponents who could impact a wetland must first attempt to avoid the impact, then if an impact is inevitable minimize the impact. Finally, the party must mitigate for any impacts that do occur. Boiling that down, if you impact an acre of wetland, you have to replace it with at least another acre of wetland.