Butterflies of Delaware County
- Presents photos and species accounts of butterflies found within the county.
- http://www.butterfliesandmoths.org/map?dc=217&_dcc=1&si=36

Delaware County Environmental Data
- Index to program areas, educational information, newsletters and events available through Ohio State University Extension.
- http://delaware.osu.edu/

Delaware Soil and Water Conservation District
- Agency responsible for protecting the natural resources within the county that assists landowners in planning and applying conservation practices on their land. Includes list of programs.
- http://www.delawareswcd.org/

Delaware County Water Resources
- Factsheet providing information on water resources and drinking-water quality in the county.
- http://ohioline.osu.edu/aex-fact/0480_21.html

Delaware County Ground-Water Resources
- Factsheet providing information on ground-water resources in the county.
- http://ohioline.osu.edu/aex-fact/0490_21.html