Flood District Outreach Project

The City Park Channel - Midway Park Modifications project budget was adopted by City Council in 2019.

The upstream limit of City Park Channel is between Hoyt Street and Burbank, just west of Aggregate Industries. The downstream limit "channel" leaves Broomfield in a box culvert just west of Chase St. and flows along the south side of W. 120th Ave to Big Dry Creek (in Westminster).

FIG 1: City Park Channel Extents in Broomfield County

This project will span from HWY 287 to Main Street and is intended as a maintenance project and will leverage maintenance funds collected by the Mile High Flood District (MHFD) through mills collected from property taxes. The project will implement the latest guidance in stream design using riffles and pools for a High Functioning Low Maintenance Stream (HFLMS) corridor. HFLMS design incorporates softer elements (vegetation), as opposed to the boulder lined section existing today, to improve habitat and decrease maintenance costs. The design will include increased meanders and sinuosity to control velocity and manage sediment deposition locations.

FIG 2: Project Area

City Park Channel is currently defined by three sections, called reaches. These reaches are defined by roadway crossings. Reach 1 - Main Street to Emerald Street, Reach 2 - Emerald Street to Midway Blvd. and Reach 3 - Midway Blvd. to US 287. Construction will begin at the downstream reach (Reach 1) of the project and work upstream (west).

FIG 3: Project Reaches

The existing stream corridor is in need of maintenance in multiple areas. The grey boulder lined section immediately west of Main Street is experiencing two significant issues: 1) water (from the creek or from irrigation) is running behind the boulders and displacing the fine material (sands and grout) anchoring the boulders in place. Some boulders have become completely dislodged and are tipped into or lying completing in the channel bottom. 2) the displacement of material by running water (sometimes called piping), is also creating sinkholes in the turf adjacent to the channel. These sinkholes may become a hazard for users of the park. The section of the creek not lined by boulders, between Nativity and Emerald schools is experiencing sloughing and erosion of the banks. Additionally, a large outfall pipe in this section is exposed for several feet. The most upstream section (from US 287 to Midway Blvd.) has similar issues with dislodged boulders.

The Mile High Flood District (MHFD), formerly known as Urban Drainage and Flood Control District (UDFCD) is a quasi-governmental body funded by mills collected from property taxes. The MHFD mission is to protect people, property, and our environment through preservation, mitigation, and education. To support this mission, the MHFD partners with local jurisdiction to construct, study and plan drainage and flood mitigation projects throughout the seven county Denver Metro area.

Broomfield will co-manage the project with MHFD project engineer and construction management staff. Broomfield will assist with outreach and updates and compliance with our Standards and Specifications. MHFD staff will manage the contractor, federal permitting (404 and environmental) and ensure compliance with the MHFD drainage criteria. The consultant and contractor are selected through the MHFD prequalified list. This ensures experience working in a creek corridor setting and understanding of the drainage and flood control impacts.

The creek corridor will certainly look different with multiple meanders and no boulder lined sections. The bank slopes will be flatter and there will be more vegetation. The intent is to keep the creek crossings in generally the same locations, though they may shift slightly. During construction, portions of the creek will be fenced off and not accessible. Post-construction a floodplain study will be submitted to FEMA to accurately delineate the floodplain based on the improvements.


The City Park Channel - Midway Park Modifications project budget was adopted by City Council in 2019.

The upstream limit of City Park Channel is between Hoyt Street and Burbank, just west of Aggregate Industries. The downstream limit "channel" leaves Broomfield in a box culvert just west of Chase St. and flows along the south side of W. 120th Ave to Big Dry Creek (in Westminster).

FIG 1: City Park Channel Extents in Broomfield County

This project will span from HWY 287 to Main Street and is intended as a maintenance project and will leverage maintenance funds collected by the Mile High Flood District (MHFD) through mills collected from property taxes. The project will implement the latest guidance in stream design using riffles and pools for a High Functioning Low Maintenance Stream (HFLMS) corridor. HFLMS design incorporates softer elements (vegetation), as opposed to the boulder lined section existing today, to improve habitat and decrease maintenance costs. The design will include increased meanders and sinuosity to control velocity and manage sediment deposition locations.

FIG 2: Project Area

City Park Channel is currently defined by three sections, called reaches. These reaches are defined by roadway crossings. Reach 1 - Main Street to Emerald Street, Reach 2 - Emerald Street to Midway Blvd. and Reach 3 - Midway Blvd. to US 287. Construction will begin at the downstream reach (Reach 1) of the project and work upstream (west).

FIG 3: Project Reaches

The existing stream corridor is in need of maintenance in multiple areas. The grey boulder lined section immediately west of Main Street is experiencing two significant issues: 1) water (from the creek or from irrigation) is running behind the boulders and displacing the fine material (sands and grout) anchoring the boulders in place. Some boulders have become completely dislodged and are tipped into or lying completing in the channel bottom. 2) the displacement of material by running water (sometimes called piping), is also creating sinkholes in the turf adjacent to the channel. These sinkholes may become a hazard for users of the park. The section of the creek not lined by boulders, between Nativity and Emerald schools is experiencing sloughing and erosion of the banks. Additionally, a large outfall pipe in this section is exposed for several feet. The most upstream section (from US 287 to Midway Blvd.) has similar issues with dislodged boulders.

The Mile High Flood District (MHFD), formerly known as Urban Drainage and Flood Control District (UDFCD) is a quasi-governmental body funded by mills collected from property taxes. The MHFD mission is to protect people, property, and our environment through preservation, mitigation, and education. To support this mission, the MHFD partners with local jurisdiction to construct, study and plan drainage and flood mitigation projects throughout the seven county Denver Metro area.

Broomfield will co-manage the project with MHFD project engineer and construction management staff. Broomfield will assist with outreach and updates and compliance with our Standards and Specifications. MHFD staff will manage the contractor, federal permitting (404 and environmental) and ensure compliance with the MHFD drainage criteria. The consultant and contractor are selected through the MHFD prequalified list. This ensures experience working in a creek corridor setting and understanding of the drainage and flood control impacts.

The creek corridor will certainly look different with multiple meanders and no boulder lined sections. The bank slopes will be flatter and there will be more vegetation. The intent is to keep the creek crossings in generally the same locations, though they may shift slightly. During construction, portions of the creek will be fenced off and not accessible. Post-construction a floodplain study will be submitted to FEMA to accurately delineate the floodplain based on the improvements.


  • News & Updates

    01 September, 2020

    Expectations during construction: For work in the parks, portions of the use area will be closed adjacent to the creek. For work on Agate and roadway crossings, detours may be in place. Access to residence homes will be maintained throughout.

  • What Does This Mean?

    01 September, 2020

    Federal Emergency Management Agency (FEMA) - FEMA is Headquartered in Washington, D.C., and has 10 regional offices located across the country. FEMA leverages a tremendous capacity to coordinate within the federal government to make sure America is equipped to prepare for and respond to disasters.

    Flood Insurance Rate Maps (FIRM) - FEMA produces Flood Insurance Rate Maps (FIRM) and Flood Hazard Boundary Maps (FHBM). The FIRM is the most common map used by communities. At a minimum, flood maps show flood risk zones and their boundaries, and may also show floodways and Base Flood Elevations (BFE). More recent flood map products include digital FIRMs (DFIRM). Communities may incorporate DFIRMs into their Geographic Information System (GIS) databases.

    Flood Zone AE Designation - "100-year" regulations/insurance requirements apply. We will provide plans and floodplain workmaps when they finalized and available.

    Floodway - A "Regulatory Floodway" means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.

    Special Flood Hazard Area (SFHA) - A SFHA is an area identified by the United States Federal Emergency Management Agency (FEMA) as an area with a special flood or mudflow, and/or flood related erosion hazard, as shown on a flood hazard boundary map or flood insurance rate map.

    Conditional Letter of Map Revision (CLOMR) – A CLOMR is a letter from FEMA's stating a proposed project that would, upon construction, affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective BFE or SFHA.

    Letter of Map Revision (LOMR) - A LOMR is the Federal Emergency Management Agency's (FEMA's) official modification to an effective Flood Insurance Rate Map (FIRM). LOMRs can result in a physical change to the existing regulatory floodway, the effective Base Flood Elevations (BFEs), or the Special Flood Hazard Area (SFHA).