The City of Boulder welcomes your feedback. Use our Inquire Boulder customer service tool to tell us what’s on your mind.

  • Assistance
  • Rebuild and Restore
  • Recovery and Resilience
  • Creek Projects
  • Maps of Floodplains
  • Floodplain Development
  • Prepare for Floods
  • Protect Your Property
  • Respond to Floods

South Boulder Creek Floodplain Mapping Study

In 2009, the city completed the South Boulder Creek Floodplain Mapping Study. 

For information about the current efforts to develop and evaluate alternatives that may reduce flooding along South Boulder Creek, please visit the South Boulder Creek Flood Mitigation webpage.

FEMA Adopts New Floodplain Mapping

The Federal Emergency Management Agency (FEMA) officially adopted new Digital Flood Insurance Rate Maps (DFIRMs) for Boulder County, including the City of Boulder, on Dec. 18, 2012. Although the new DFIRMs are generally consistent with the existing DFIRMs, the new mapping incorporates the South Boulder Creek Floodplain Mapping Study and also de-certifies three levees within the city.

Dec. 18, 2012:  FEMA formally adopts South Boulder Creek Floodplain Maps

Summer/Fall 2012 - The FEMA informed the city that it will not officially adopt the floodplain maps provided by the city until late 2012. This gives property owners more time to apply for floodplain insurance if their property is located within the revised 100-year floodplain boundary.

Under National Flood Insurance Program (NFIP) regulations, if your property is located in the 100-year floodplain and is financed by a federally-backed mortgage, you must purchase flood insurance. Most home mortgages fall under this category, since most lenders are federally regulated.

The requirement to purchase flood insurance will not be mandatory until FEMA adopts the proposed revision of the Digital Flood Insurance Rate Map (DFIRM). It is best to obtain flood insurance prior to the adoption of the floodplain maps, because insurance may be less expensive if purchased prior to adoption.

January 2012 - Approximately $4.25 million has been included in the city's 2012 budget to help fund the construction of flood mitigation projects.

July 30, 2009 - The City of Boulder and the Urban Drainage and Flood Control District solicited proposals from qualified consultants for the South Boulder Creek Flood Mitigation Planning Study.

June 2009 - The Updated Risk Assessment Report was completed to support subsequent flood mitigation planning.

Jan. 29, 2009 - Memo to City Council: Mapping study update and plan for new floodplain regulations.

Study Impacts

In March 2009, FEMA notified the city that it intended to officially adopt the revised floodplain maps that resulted from the South Boulder Creek Floodplain Mapping Study. The new maps will serve as the basis for the Digital Flood Insurance Rate Maps, which establish minimum regulatory floodplain boundaries for the National Flood Insurance Program, as well as for flood insurance purchase requirements. 

The city began regulating the designated floodplain areas on Jan. 1, 2008, based on the previous study results. A few properties were added to the 100-year floodplain based on the information submitted to FEMA at the end of 2008. Staff began regulating these properties on April 1, 2009 and sent the property owners a Notification Letter.

Project Document Archives

Hard copies of historical material pertaining to this study are available for review and copy at the Boulder Public Library, 1000 Canyon Blvd.