# load libraries
library(tidyverse)
library(nhdplusTools)
library(sf)

# load extent of map
extent <- read.csv(file = "extent.csv")
crs <- 26916

extent_poly <- st_polygon(
  x = list(
    cbind(
      extent$longitude[c(1,2,2,1,1)], 
      extent$latitude[c(1,1,2,2,1)])
  )
)

extent_poly <- st_sfc(extent_poly, crs=4326)

extent <- list(longitude_max = max(extent$longitude),
               longitude_min = min(extent$longitude),
               latitude_max = max(extent$latitude),
               latitude_min = min(extent$latitude))


# get watershed areas
extent_huc <- get_huc(AOI = extent_poly, buffer = 0, type = "huc04")

# download data
download_nhdplushr("data", extent_huc$huc4, download_files = TRUE)