This function downloads Watershed Boundary Dataset (WBD) HUC polygons
for a given county in Washington and clips HUC polygon to the conservation district
provided. Optionally saves the results as a shapefile. Clipped acres of
each watershed are automatically recalculated and added as Acres_in_huc variable
Arguments
- district_name
Character. Name of the district (e.g., "Columbia").
- huc_level
Character. One of "huc02" "huc04" "huc06" "huc08" "huc10" "huc12" "huc12_nhdplusv2"
- save_shp
Logical. Whether to save the result as a shapefile. Default is FALSE.
- shp_path
Character. File path to save shapefile (without extension). Default is NULL.
