streamstats_watershed.R

library(jsonlite);library(sf)

#lon = -123.1121
#lat = 44.6390
#state = 'OR'

watershed = function(state, lon, lat){
  p1 = 'https://streamstats.usgs.gov/streamstatsservices/watershed.geojson?rcode='
  p2 = '&xlocation='
  p3 = '&ylocation='
  p4 = '&crs=4326&includeparameters=false&includeflowtypes=false&includefeatures=true&simplify=true'
  
  query <-  paste0(p1, state, p2, toString(lon), p3, toString(lat), p4)
  
  mydata <- fromJSON(query)
  tmp <- mydata$featurecollection[2,2]
  stringJson <- toJSON(tmp)
  new <- substr(stringJson, 2, nchar(stringJson) -1) 
  final <- st_read(new)
  final
}

ws = watershed(state, lon, lat)
plot(ws$geometry, col='red')