Making state water files. Your paths will vary.

Makefile

# usage: make water STATE=06

water:
	# note that I've previously downloaded all county water files from ftp2.census.gov/geo/tiger/TIGER2020/AREAWATER
	# to /Volumes/jkeefe-data/2020_Census/AREAWATER on my computer
	mkdir -p ./tmp/water
	rm ./tmp/water/*.*
	cd /Volumes/jkeefe-data/2020_Census/AREAWATER; unzip -o "tl_2020_$(STATE)*.zip" -d /Users/keefe/cnnvis-census2020-dot-maps/tmp/water
	npx mapshaper -i './tmp/water/*.shp' combine-files \
	-simplify 40% \
	-merge-layers \
	-proj EPSG:4326 \
	-o datawork/water/water_$(STATE).geojson