Download StreamCat metric file for a state and subset to counties of interest

StreamCatCountySubset.r

library(sf)
library(tigris)

setwd('H:/WorkingData')
temp <- tempfile()
download.file("https://gaftp.epa.gov/EPADataCommons/ORD/NHDPlusLandscapeAttributes/StreamCat/States/ImperviousSurfaces2006_WA.zip",temp)
wa <- read.csv(unz(temp, "ImperviousSurfaces2006_WA.csv"))
unlink(temp)

counties <- counties("Washington", cb = TRUE)

counties <- counties[counties$NAME %in% c('Kitsap','King','Pierce','Jefferson','Snohomish'),]
# get NHDPlus catchments - all of WA is in NHDPlus region 17
cats <- st_read('L:/Priv/CORFiles/Geospatial_Library/Data/RESOURCE/PHYSICAL/HYDROLOGY/NHDPlusV21/NHDPlusPN/NHDPlus17/NHDPlusCatchment/Catchment.shp')
# subset catchments to just counties of interest  
# align CRS
counties <- st_transform(counties, st_crs(cats))
ggplot(counties) +
  geom_sf() +
  ggtitle("Counties in WA") +
  theme_bw()
county_cats <- cats[counties,]

# Now subset the StreamCat metric file
wa_counties_imperv <- wa[wa$COMID %in% county_cats$FEATUREID,]
head(wa_counties_imperv)