{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "This map identifies areas where the groundwater surface (water table) is currently less than 10 feet below the land surface. The purpose of this work is to identify vulnerable areas within the zone where groundwater is projected to rise with SLR, and where groundwater levels are already shallow. Many forms of infrastructure, including pavements and other transportation assets, septic systems, sewer pipes and pumping stations, stormwater BMPs, basements, and historic places, may be negatively affected by shallow groundwater.\n\nGeneralized impacts associated with groundwater depth zones:\n0\u20135 ft - Critically shallow. High risk of direct interaction between groundwater and buried structures. Roads and pavements; basements/foundations; septic systems; most buried utilities; stormwater assets; private wells; contaminated sites; critical facilities.\n\n5\u201310 ft - Transition zone. Still crucial for performance and for near-term rise. Deeper sewers and storm drains; many infiltration/green infrastructure practices; some foundations; wells in sensitive aquifers; some contaminated sites.\n\n10\u201315 ft - Future risk/planning zone, and relevant for very deep or critical assets. Deep-trunk utilities, large below-grade structures, and long-lived infrastructure that will experience groundwater rise over their design lives.", "description": "
Groundwater modeling was used to simulate the effects of sea-level rise on groundwater levels in the New Hampshire Seacoast. The calibrated MODFLOW-USG Transport model (Panday, 2022) was used to simulate groundwater elevations under current sea levels and under various sea-level rise scenarios. Groundwater depth without SLR was estimated by subtracting the current groundwater levels from LiDAR ground surface elevations. Groundwater depths of less than 15 ft, 10 ft, and 5 ft were mapped for the current conditions. Groundwater depth for the various SLR scenarios can be estimated by subtracting the simulated SLR-induced groundwater rise from the current groundwater depth.<\/SPAN><\/P><\/DIV><\/DIV>", "summary": "This map identifies areas where the groundwater surface (water table) is currently less than 10 feet below the land surface. The purpose of this work is to identify vulnerable areas within the zone where groundwater is projected to rise with SLR, and where groundwater levels are already shallow. Many forms of infrastructure, including pavements and other transportation assets, septic systems, sewer pipes and pumping stations, stormwater BMPs, basements, and historic places, may be negatively affected by shallow groundwater.\n\nGeneralized impacts associated with groundwater depth zones:\n0\u20135 ft - Critically shallow. High risk of direct interaction between groundwater and buried structures. Roads and pavements; basements/foundations; septic systems; most buried utilities; stormwater assets; private wells; contaminated sites; critical facilities.\n\n5\u201310 ft - Transition zone. Still crucial for performance and for near-term rise. Deeper sewers and storm drains; many infiltration/green infrastructure practices; some foundations; wells in sensitive aquifers; some contaminated sites.\n\n10\u201315 ft - Future risk/planning zone, and relevant for very deep or critical assets. Deep-trunk utilities, large below-grade structures, and long-lived infrastructure that will experience groundwater rise over their design lives.", "title": "Groundwater depth (GWD) zones with No Sea Level Rise (SLR) - Areas within the Groundwater Rise Zone (GWRZ) where the GWD is less than 15 feet below the ground surface.", "tags": [ "environment", "geoscientific information", "inland waters", "shallow groundwater", "coastal flooding", "NH Seacoast", "resiliency planning" ], "type": "", "typeKeywords": [], "thumbnail": "", "url": "", "minScale": 150000000, "maxScale": 5000, "spatialReference": "", "accessInformation": "", "licenseInfo": "", "portalUrl": "" }