A Look at the Trump Administration’s final WOTUS definition

in North Carolina

Prepared by John Dorney, Moffatt & Nichol - Raleigh

Thursday, March 12, 2020
Peculiar Rabbit: 1212 Pecan Ave. Charlotte, NC 28205

• Social Hour starting at 5:30 PM
• Dinner at 6:30 PM
• Speaker at ~7:00 PM

Moffatt & Nichol was hired in early 2019 by the Southern Environmental Law Center to conduct an objective, science-based analysis of the proposed WOTUS definition on the extent of waters (wetlands and streams) in NC and the Southeast based on existing, public data sets.  We have now revised our report based on a pre-publication version of the final rule published on January 23, 2020.  The following results pertain to the effect of the final rule on the jurisdiction of streams and wetlands in NC and the Southeast.

Streams – The proposed definition would remove ephemeral streams and most ditches from jurisdiction for 404 Permitting which would likely have a minor effect on the extent of stream jurisdiction in NC. We used the NC Division of Water Quality stream mapping data set to estimate the extent of intermittent and perennial channels in the state. If only perennial streams had been regulated (which was a possible outcome of the draft rule), then an average of at least 27% of the stream length statewide would no longer be regulated. The extent of jurisdictional, ephemeral stream length is unknown in NC and the Southeast.

Wetlands - The proposed wetland definition would remove from jurisdiction wetlands that do not directly abut or do not have a direct hydrological connection with a jurisdictional channel (intermittent or perennial streams) to downstream waters.  The final rule added a few uncommon instances where wetlands could still be jurisdictional with an ephemeral channel connection. These circumstances will be discussed at the meeting. Therefore, generally wetlands connected by an ephemeral channel or ditch to downstream waters would not be regulated.  We are unable to estimate the size of the statewide reduction on wetland jurisdiction since accurate wetland and stream flow duration maps are not available in NC. However, based on an analysis of existing wetland databases and selected large projects, we conclude that there would be a major reduction in the extent of regulated wetlands in NC based on the proposed rule but the amount would vary greatly by physiographic region and wetland type. Overall, losses would be greatest in the Piedmont and Inner Coastal Plain. Wetland types with the greatest losses would likely include floodplain pools, seeps, non-riverine swamp forest, pine savanna, pine flat, headwater forest, bog, and bottomland hardwood forest communities. For instance, from one comprehensive dataset the loss of headwater forests in the piedmont and coastal plain could be 29%.