Floodplain Remapping Project

Floodplain Remapping Project


Use the links below to view the draft maps and to provide input or ask questions:

View the Floodplain Map
Draft and regulatory flood risk zones are all visible on this interactive webmap (Data updated on June 1, 2017 to reflect adopted changes to the Boulder County Floodplain).

  • Proposed Regulatory Flood Risk Zones – Read about draft floodplain map data visible on the webmap portal (link above) and learn how these maps are related to the proposed revisions to the Floodplain Overlay Zoning District for Phase II of the CHAMP Study
  • Online Comment Form – Submitted forms are sent directly to the county project team



The data available online via our floodplain map web portal is available to allow the public to be aware of and provide input on the floodplain remapping project from the beginning. Draft map data from Phase I of the CHAMP and related flood studies was adopted June 1, 2017 and map layers in these reaches have been updated to reflect this regulatory change.

Draft map data for Phase II of the CHAMP study will be available for review in early 2018, although data for the Little Thompson reaches within Boulder County are already viewable. Concerns or questions about these changes should be addressed to the Floodplain Management Team (contact info at the bottom of this page).


The 2013 flood event caused widespread damage and changes along waterways throughout the county and other areas of the state. In response, the State of Colorado is taking steps towards bolstering long-term planning and resiliency efforts by funding the Colorado Hazard Mapping Program (CHAMP) that will update local hazard information including regulatory floodplain maps for the most affected waterways.

Boulder County is supporting this initiative because accurate floodplain maps provide detailed information for property owners on their own flood risks and enable proactive measures to protect people and property before the next significant flood event.

Updated maps for the St. Vrain watershed and Phase I of the CHAMP study were submitted to the county in the fall of 2016 and adopted in May 2017. Floodplain maps are under revision for the following waterways (or reaches therein):

  • Cabin Creek
  • North – South – Middle St. Vrain Creek(s)
  • St. Vrain Creek
  • Boulder Creek
  • North Boulder Creek
  • Middle Boulder Creek
  • South Boulder Creek
  • Dry Creek #2
  • Two Mile Canyon Creek
  • Coal Creek
  • Rock Creek
  • New Dry Creek Ditch
  • Upper Four Mile Canyon Creek

Map of creeks in Boulder County with floodplain remapping occuring as of January 2017Other area waterway floodplain maps will be released in the fall of 2017 as part of the CHAMP Phase II study. The floodplain mapping will be recommended for local adoption as it is reviewed and approved by the county. This will allow the county to base floodplain regulations on the best available data. Later, upon final FEMA approval and adoption, the floodplain mapping will become effective for both regulatory and flood insurance purposes. Read more about these components of the floodplain remapping process on the Floodplain Mapping and Code Amendments page and the National Flood Insurance (NFIP) page.

To educate and engage residents, Boulder County will provide information and updates throughout the state’s process via this website and a variety of other platforms. Use the links on the right side of this page to learn more about this effort.

Contact Us

Floodplain Administrator Contact

Floodplain Administrator



2525 13th Street
Boulder, CO 80304

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Hours: 8 a.m. - 4:30 p.m. M-F

Mailing Address

P.O. Box 471
Boulder, CO 80306