Nationwide permit program: Unknown adverse impacts on the commonwealth of the northern Mariana Islands’ Wetlands

Abstract

Of the 39 Nationwide Permits (NWPs) that came into effect on 11 February 1997, 11 authorize activities that could impact Commonwealth of the Northern Mariana Islands (CNMI) wetlands. Because managers of CNMI wetlands lack an accurate scientific basis for determining the significance of proposed wetland impacts, the CNMI denied and conditioned Clean Water Act Section 401 Water Quality Certifications and Coastal Zone Management Act Section 307 consistency concurrences for these 11 NWPs to reduce the likelihood of the U.S. Army Corps of Engineers (Corps) authorizing more than minimal adverse wetland impacts under the NWP program. The CNMI decided that the benefits of requiring a more stringent review process outweigh the costs of increasing the regulatory burden on developers. A review of authorized CNMI wetland impacts indicates that the loss of wetland quantity under the NWP program on Saipan is minimal. However, managers do not know if the site specific and cumulative loss of wetland quality— wetland functional performance and provision of valued services— is significant. The Corps authorized 7 projects under NWPs that impacted CNMI wetlands. These 7 projects impacted 10 of Saipan's 37 freshwater wetlands and filled approximately 3.6 hectares or 1.5% of the island's total freshwater wetland area. Seven of these 10 affected sites were isolated wetlands. Nationwide, the Corps does not know if the cumulative loss of wetland area, functions, and values authorized under the NWP program has been minimal because the Corps has incomplete data on wetland impacts. Also, because most regions of the United States lack standardized assessment methods that estimate changes in functional performance and provision of valued services by local wetland classes, because many regions do not have the ability to define thresholds for cumulative wetland impacts, and because even small, isolated, and temporary wetlands may possess valued functions, the Corps does not know if wetland impacts authorized under the NWP program have been minimal. The Corps lacks an accurate basis for defining what constitutes a more than minimal adverse wetland impact to implement the NWP Program. Regulators assume that conserving wetland area prevents a net loss of functional performance and the provision of valued wetland services, but they have no means to confirm the accuracy of this assumption. Conditioning and denying the use of NWPs that could be used to authorize wetland impacts creates a more stringent review process but still results in the continued authorization of unknown wetland impacts under provisional NWPs and Individual Permits. A proposed solution is to develop regional wetland assessment methods for each wetland class to allow for the management of the project‐specific and cumulative effects of wetland degradation on wetlands functional performance and provision of valued services. This provides wetland managers with the requisite information to condition relevant NWPs to ensure that no more than minimal adverse wetland impacts are authorized in their region.