Welcome to DunnHydroGeo

Dear Website Visitor:

I am pleased that you are visiting my hydrologic and geologic website. Feel free to ask questions on any of the pages listed in the sidebar menu (hamburger menu for phones). I will also provide limited gratis responses to hydrologic and geologic inquiries about other topics. I provide some information and comments based on previous viewer inquiries in web pages titled Groundwater Topics, Surface Water Topics, and Geology Topics. My email address is in the footer below.

My most recently completed project for a client was a groundwater resource assessment. This work involved gathering and analyzing information on the capacity of water wells and springs. If you have a hydrologic or geologic task you would like me to execute, please send a request.

My most recent gratis consulting involved hydrogen sulfide in groundwater.

The most viewed web pages on this site in August 2020 were the non-technical pages on (1) flow duration curves, (2) aquifer step testing, and (3) injection well testing.

I am especially interested in application of computer software to hydrologic and geologic problems. I am currently working with MODFLOW 6 and MT3D-USGS. MODFLOW 6 is the most recent version of a widely used groundwater flow computer model created and maintained by the United States Geological Survey. MT3D-USGS uses output data from MODFLOW 6 to simulate the movement of dissolved substances (usually contaminants) within the groundwater model.


Darrel Dunn, Ph.D., PG

Consulting hydrogeologist-geologist

Come visit Colorful Colorado.