Saltwater Intrusion Modeled Areas

This map shows the model domains used to simulate saltwater intrusion. The first groundwater model constructed was the NH Seacoast model. This model originated from the USGS Groundwater Model constructed by Thomas Mack (Mack, 2009). We modified the model to simulate groundwater rise caused by SLR (Knott et al., 2019). For this project, the model was converted to MODFLOW-USG and updated to be consistent with the other models. Converting it to a saltwater intrusion model was beyond this project's scope; consequently, saltwater intrusion was not simulated in the southeastern NH Seacoast model domain. The "Dover_Plus & Durham" model domain includes the coastal areas of Rollinsford, Dover, Madbury, and Durham. A new groundwater model with SWI was constructed for the northern communities and was merged with the existing Durham groundwater model (Pimental et al., 2022). Another groundwater flow and SWI model was built for Newmarket, Newfields, Exeter, and part of Stratham. This is labeled "Newfields & Exeter" on the domain map. The "Portsmouth & NC" domain consists of a new groundwater flow and SWI model for Portsmouth, Newington, New Castle, and part of Rye. All models constructed for this project used the MODFLOW-USG Transport code and are capable of simulating contaminant transport in addition to GW flow in the future if needed.