Watershed Modeling
The watershed modeling project generated watershed maps for the San Juan Archipelago at a variety of scales or basin resolution levels. The project enables San Juan County to use the model for any island within the county and to run the model at any sensitivity level necessary to address the need at the time.

The watershed modeling project uses USGS National Elevation Data and ESRI watershed delineation model tools to generate watershed maps for the San Juan Archipelago at a variety of scales or basin resolution levels. The project uses computer modeling techniques that are freely available to most entities using ArcGIS technology. The data preparation portion of the project enables San Juan County to use the model for any island within the county and to run the model at any sensitivity level necessary to address the need at the time. Note: The 160 – 320 acre scale appears to most accurately reflect the natural systems for most of the islands.

Coastal Wetland Delineation
The Coastal Wetland Delineation project converted paper based aerial photographs from 1983 that had been marked up and annotated to delineate significant coastal wetlands to a georeferenced GIS map layers with attributes reflecting the annotation of the paper based maps. Comparing the data generated in this project highlighted several areas where there are substantial differences in the size or shape of the wetland when compared to current data. Field survey work is necessary to determine if the differences are due to errors induced by the various mapping methods, other than normal variability, and important enough to warrant particular management measures.

There are several components to the map layers. There are georeferenced scans of the aerial photos; digitized polygons of the delineated wetlands where the delineation on the paper maps was a closed polygon; and digitized lines of the delineated wetlands where there were no polygons. The digitizing was done using a semi-automated process that is distributed by ESRI with ArcGIS products.