• Evening in downtown Caldwell

    photo credit: Dan Smede

  • Winter Wonderland 2019 Festival

    Destination Caldwell

  • Main Street, circa 1950-s - Ellis

    photo credit - unknown

  • 2018 4th of July Fireworks

    Dan Smede

  • Historic Caldwell Home

    Jan Boles

  • Old City Hall, circa 1930

    photo credit: unknown

  • Cardboard Kayak Races - 2018

    Destination Caldwell

  • Indian Creek Plaza ice ribbon

    Destination Caldwell


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Annual MS4 Reports

2019: City of Caldwell 10th Annual Report

2018: City of Caldwell 9th Annual Report

2017: City of Caldwell 8th Annual Report

2016: City of Caldwell 7th Annual Report

2015: City of Caldwell 6th Annual Report

2014: City of Caldwell 5th Annual Report

2013: City of Caldwell 4th Annual Report

2012: City of Caldwell 3rd Annual Report

2011: City of Caldwell 2nd Annual Report

2010: City of Caldwell 1st Annual Report

Permit     Modified start date letter

Note: Appendices for past Annual MS4 Reports are available upon request.  Please email the stormwater personnel at the bottom of this page.

Municipal Stormwater Management Manual

The City of Caldwell will consider revisions to the current Caldwell Municipal Stormwater Management Manual.  Please send your requests and recommendations via email or letter via the contact information below.  An open house will be held for the public to offer input on proposed changes.  

Public Education

The City of Caldwell has joined with Boise City, Garden City, Boise State University , Ada County Highway District, Ada County Drainage District No.3  and Idaho Transportation Department, District 3  in Partners for Clean Water to have a regional outreach to our public education program.


  • Caldwell Waterway Day - The City of Caldwell participates in an annual waterway cleanup of Boise River, Indian Creek, and/or other local waterways that flow through Caldwell.  Please contact us using the information below if you would like an invitation to participate in our next public event!
  • Watershed Watch! - Individuals, families and groups can take part in the watershed-wide effort to collect water quality data along the shores of the Boise River, ponds, reservoirs and creeks. The event takes place in the fall at various sites from Lucky Peak to Parma.
  • Storm Drain Marking for Community Service Projects  - Storm drain stenciling projects are coordinated in Caldwell depending on annual requirements.  If you would like to request a storm drain marking project specifically for your scout group or for educational community service hours, please contact us at least one month in advance of your project start date.  

Thank you to all who have participated in Boise RiverSweep, Watershed Watch, Waterway Cleanup Days since 2010!

Illicit Discharge

Public citizens can report an illicit discharge to the City storm drain by contacting Ashley Newbry via the methods at the bottom of this page.   Alternately, you may write to our office at the following address: 621 Cleveland Blvd, Caldwell, ID 83605.  Before you call, please verify that the discharge is illicit by reading the Storm Water Ordinances.


The City of Caldwell stormwater and engineering staff inspect the onsite implementation of Storm Water Pollution Prevention Plans (SWPPP).  Please contact EPA to file your project notice of intent (NOI).   All construction within City limits are subject to enforcement of SWPPP documentation submitted to EPA and City Erosion and Sediment Control Ordinances.

Caldwell Industrial Airport

Caldwell Industrial Airport SWPPP - Jan 2020

Sampling Data Summary | Site Map 1: Boundary and Size | Site Map 2: Significant Structures & Impervious Surfaces | Site Map 3: Stormwater Flow | Site Map 4: Stormwater Control Measures | Site Map 5: Receiving Waters | Site Map 6: Stormwater Conveyance | Site Map 7: Pollutant Sources | Site Map 8: Spills | Site Map 9: Monitoring Points | Site Map 13: Activities Exposed to Precipitation | Slickspotted Peppergrass Exhibit

Stormwater Quality Contact

Ashley Newbry, PE

Engineering Department Stormwater Program

208-455-3006 | anewbry@cityofcaldwell.org

Waterway Cleanup 2019

Updated on 01/15/2020 2:27 PM

Community Cleanup at Rotary Pond and Boise River Greenbelt in Caldwell, Idaho

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