Englewood council reviews flood-basin prioritization study; city, Mile High Flood District identify three top basins

The City of Englewood and the Mile High Flood District presented results of the Englewood Flood Hazard Mitigation Basin Prioritization Study at a special City Council study session, laying out a ranking of 19 drainage basins and recommended next steps that include formal floodplain mapping and targeted capital projects.

The study, presented by Tim Host, Deputy Director of Engineering for the City of Englewood, and Jennifer Winters, watershed manager at the Mile High Flood District, used citywide hydrologic modeling, land-use and population data, and critical‑infrastructure overlays to score basins for public‑safety and equity concerns. "The official title of this report is the Englewood Flood Hazard Mitigation Basin Prioritization Study," Host said as the presentation opened.

City and district staff said three basins rose to the top of the prioritization: Little Dry Creek, Dry Gulch and the South Englewood Basin. Jennifer Winters described the scoring framework: "We looked at flood water inundation, land use and zoning and critical infrastructure," and combined depth, velocity, resident vulnerability and presence of schools or medical facilities to create a composite ranking.

Why it matters: the study is intended as a planning tool to direct scarce capital funds toward projects that deliver the greatest public‑safety benefit. City staff emphasized the study does not itself change FEMA flood maps or require immediate construction; instead it is intended to guide future design and capital improvement planning.

Key findings and recommendations

- Scope and methods: The team modeled a range of storm scenarios across the whole city, identifying where stormwater flows to low points and how deep and fast water would be in a 100‑year event. The study mapped areas with less than 1 foot of depth, between 1 and 2.5 feet, and greater than 2.5 feet, and then layered zoning, population density and social vulnerability indicators on top of the flood results.

- Priorities: Little Dry Creek, Dry Gulch and South Englewood Basin scored highest across the combined criteria, staff said. Little Dry Creek requires a separate, more detailed hydrology study because of its large upstream drainage area that includes Cherry Hills Village and Centennial. Dry Gulch already has an active capital improvement project; consultants are expected to be selected in April, and staff said construction could begin as early as 2027. For South Englewood Basin, the City’s current target is to achieve 25‑year capacity as the immediate milestone.

- Next steps and mapping: For each high‑priority basin staff recommended official 100‑year flood mapping to support infrastructure decisions and homeowner notification. Winters explained the study’s 100‑year modeling was planning‑level and that formal flood‑plain maps for regulatory and insurance purposes would require a separate, more detailed mapping effort.

- Funding saved and flexibility: City staff said about $5,000,000 has been collected for projects in the South Englewood Basin and roughly $2,000,000 is allocated for Dry Gulch; the funding agreement with the flood district allows funds to be reallocated if a project is certified complete.

Council questions and concerns

Council members pressed staff on development, timetables and neighborhood impacts. Council Member Rita Russell said she was concerned about ongoing approvals in high‑priority basins and rising density: "I don't know. But I'm very concerned that we just keep studying, but never learning. And when are we going to start implementing what we've, what we're figuring out?" Russell asked, citing a recently approved project in the Little Dry Creek basin and other changes that will increase impervious surface.

Director of Public Works Victor Rochelle said developers have been given and are using the most recent adopted studies during permitting. "Sam's is doing detention as well," Rochelle said, noting that some projects include detention and water‑quality measures and that the city evaluates development against adopted standards at the time of permit review.

Council members also asked whether previously completed projects have reduced risk in South Englewood. Tim Host and Winters said earlier work reduced the number of structures in the floodplain and that the district and city plan to hire a third‑party modeler to verify whether 25‑year protection has been achieved after recently completed and ongoing construction. "If the answer is yes," Winters said, "then we can take those funds we've been collecting and move them to another priority basin."

Other technical points

- The study distinguishes planning‑level 100‑year modeling from FEMA regulatory flood mapping; staff recommended follow‑on mapping for decision‑making and resident notification. Dry Gulch and Little Dry Creek already have FEMA floodplain designations in portions of their corridors; South Englewood does not. Staff recommended updating FEMA or local mapping after targeted CIP projects.

- The South Englewood Basin work includes large detention ponds, a tunnel and culvert infrastructure; staff noted the tunnel pipe is sized for a 100‑year event to avoid repeated reconstruction.

- A range of non‑structural actions were also recommended: update GIS stormwater data, study roadway crossings, strengthen multi‑agency coordination, and expand public outreach and education.

What council directed or decided

Tonight’s session was a study presentation; council did not take a formal vote. Council members requested additional detail and follow up in several areas: verification of how adopted drainage standards were applied to recent developments in high‑priority basins; a third‑party review to confirm South Englewood Basin 25‑year capacity after construction; and clearer resident notification about flood risk and available mitigation grants for affected homeowners. Staff said they would return with more detailed mapping, hydrology reports and implementation steps.

Looking ahead

Staff said they will pursue floodplain map revisions as part of basin‑level follow up, continue collaboration with the Mile High Flood District and begin the detailed studies or CIP design work for the three priority basins. Little Dry Creek’s hydrology update is already underway; Dry Gulch has an active CIP procurement scheduled; South Englewood will undergo an independent verification of 25‑year capacity as a next step.

End note: Council members called for ongoing, clearer communication with neighborhoods in all basins and for staff to ensure that pending and future developments are reviewed against the latest studies and standards.