Addressing Coastal Hazards

What are Coastal Hazards in the CNMI?

Since all of the Northern Mariana islands are within the coastal zone, coastal hazards impact our livelihoods and factor into where development will go. The islands are located in the West Pacific Typhoon Alley, so typhoons are common during the annual wet season. Top coastal hazards of the CNMI are typhoons, storm surges, and flooding. Typhoon Soudelor (2015) and Super Typhoon Yutu (2018) are serious reminders of how typhoons can impact property, and the environment. Shoreline erosion is also a persisting hazard for residential and economically-valued infrastructure as increased land loss may be exposed to typhoon-generated storm surges. Sea level rise may further exacerbate this problem in low-lying areas, such as Tanapag, Garapan, and Susupe. Flooding can occur during the wet season when the rate of rainfall is increased, potentially damaging homes and polluting coral reefs. Government agencies, both local and federal, are collaborating to address coastal hazards and ultimately support community resilience.

How is DCRM Addressing Coastal Hazards?

DCRM considers Coastal Hazards as an Area of Particular Concern (APC). They are defined as areas identified by the Federal Emergency Management (FEMA) Flood Insurance Rate Maps (FIRMs) as coastal high hazard flood zones (V & VE). Refer to the APC Map below to view the current Coastal Hazards APC Layer. You can also access the CNMI Climate Viewer, a helpful tool showcasing coastal inundation areas and social vulnerability, here.

Click here to view the Interactive APC Map: https://dcrm.maps.arcgis.com/apps/webappviewer/index.html?id=5b47ed37bf2340e282b0a0944f96a475. Coastal Hazards areas are indicated in dark yellow.

Through DCRM’s Permitting process, proposed development within the Coastal Hazards APC must adhere to appropriate building codes and ensure that public safety is prioritized. Shoreline dependent projects must abide by the following setbacks from the high waterline:

  1. A) 0-35 ft to maintain beach and shoreline for public access and recreations with structures generally prohibited;
  2. B) 35-100 ft to allow for the continuation of the shoreline area with vertical construction prohibited;
  3. C) 100-125 ft to only allow single-story structures not exceeding 12-ft in height with water quality and shoreline dynamics carefully considered through the Mitigation Hierarchy.

Usually, conditions are placed in the Coastal Hazards APC permit for enhancement of shoreline areas, such as consideration of living shorelines for addressing on-going erosion, or storm water mitigation to prevent pollution from flowing into the lagoon.

Coastal hazards is also continually identified as a priority enhancement area of NOAA’s Coastal Zone Enhancement Program (309) in the CNMI. From the 2016-2020 309 cycle, important inter-agency work emerged in addressing Coastal Hazards, such as the Low-Impact Development Best Management Practices Report, Sustainability Guide for the Hospital Industry, and the Guidance Manual for Smart, Safe Growth in the CNMI. The Better Buildings guidebook will build off of these documents to implement best management building practices for reducing storm water, increasing typhoon resilience, and lessening other environmental impacts. The guidebook will inform the development of an incentives program under the Permitting Section to encourage low-impact, climate-smart development.

 

Helpful Resources:

Coastal Hazards, Climate, and Shoreline Change Resources & Publication page: https://dcrm.gov.mp/resources-publications/coastal-hazards-climate-change-and-shoreline-change/

Sustainable Development Resources & Publication page: https://dcrm.gov.mp/resources-publications/sustainable-development/

Shoreline Publications Resources & Publication page: https://dcrm.gov.mp/resources-publications/shoreline-publications/