Boulder County government offices are closed Wednesday, June 19, in observance of Juneteenth. Primary Elections Vote Center locations are open.


The Boulder County Public Works Department has turned over the responsibility of the Ditch and Reservoir Directory to the St. Vrain and Left Hand Water Conservancy District. They will be gathering the updates and publishing the Ditch and Reservoir Directory.

Ditch & Reservoir Directory

  • Boulder County Ditch Map
    • DISCLAIMER – This data has been developed by Boulder County and may also include data from third-party sources, Boulder County makes no warranties, representations, or guarantees, either expressed or implied, as to the completeness, accuracy, or correctness of the data, nor accepts or assumes any liability arising from or for any incorrect, incomplete, or misleading data provided pursuant to the use of this data. There are no warranties and/or representations, either expressed or implied, of merchantability or fitness of the data for a particular purpose or use.
  • The St. Vrain and Left Hand Water Conservation District produces a Ditch and Reservoir Directory for all privately owned & maintained ditches in the county. Look for the link underneath the “Basin Contact Information and Ditch Directory” header.

Questions, corrections contact the St Vrain and Left Hand Water Conservancy District at 303-772-4060 or email

Contact Us

Public Works Department (formerly Transportation)

Submit a request


2525 13th St.
Boulder, CO 80304

Map and Directions

Hours: Building Open 8 a.m. to 4:30 p.m.
Tuesdays and Thursdays

Mailing Address

P.O. Box 471
Boulder, CO 80306