Iliff Stormwater Basin | Goldsmith Gulch Stormwater Project

Why Are Improvements Needed?

Iliff Basin is a stormwater detention area located along Goldsmith Gulch that helps reduce flooding during larger storm events.

Today, the basin captures runoff during moderate storms, but it faces several challenges:

The basin can collect standing water when pumps are not functioning properly.
The area is difficult to use as a community space.
The basin requires ongoing maintenance and pumping operations.
During larger storms, the basin's flood protection benefits become limited.
Residents have expressed concerns about stagnant water, aesthetics, and underutilized open space.

What We Heard in Phase 1 Engagement

Top Community Priorities Included:

What Will Change?

Transforming "The Pit"

The proposed concepts would partially fill portions of the existing basin and raise its bottom elevation.

This would allow stormwater to:

Drain naturally by gravity and eliminate the need for pumps
Reduce the potential for stagnant water
Create new opportunities for recreation and environmental enhancements

Map of Iliff Stormwater Basin with improvements that focus on Riparian Extension.

Alternative A: Open Park and Floodplain

This concept transforms the basin into a large, open community space while improving flood protection and restoring natural drainage. The existing berm that separates the basin from Goldsmith Gulch would be removed, allowing stormwater to spread into a broader natural floodplain during larger storm events.

Most of the basin would be regraded to create approximately four acres of usable open space that could support future park amenities, community gatherings, recreation, or flexible programming. A loop trail around the basin would provide opportunities for walking, biking, and enjoying the area year-round. During major storms, some trail segments may temporarily flood, but the design is intended to reduce standing water and eliminate the need for the existing pump system.

Key Features

Large open space for future park uses
Loop trail around the basin
Improved natural floodplain connection
Reduced standing water and pump maintenance
Habitat and ecological enhancements along the creek corridor

Map of Iliff Stormwater Basin with improvements that focus on creating a berm and bridge system to allow water to flow.

Alternative B: Nature-Focused Floodplain with Habitat Island

This concept builds on the same flood protection improvements as Option A but creates a more naturalized landscape along Goldsmith Gulch. Rather than removing the entire berm, a portion would be retained as a raised "island" feature within an expanded floodplain area.

New side channels and wetland features would create additional habitat for plants and wildlife while helping manage stormwater. Pedestrian bridges and trail connections would allow visitors to experience the restored creek environment up close. The basin floor would still be regraded to create open space for future park uses and community activities, while the eastern edge becomes a more natural ecological corridor.

Key Features

Expanded creek and floodplain habitat
Naturalized side channels and wetland areas
Raised island feature within the floodplain
Pedestrian bridges and enhanced trail access
Open space for future recreation and programming
Reduced standing water and elimination of pump infrastructure

Goldsmith Gulch Stormwater Project

Iliff Stormwater Basin Area Improvements "The Pit"

Why Are Improvements Needed?

What We Heard in Phase 1 Engagement

Top Community Priorities Included:

What Will Change?

Transforming "The Pit"

Alternative A: Open Park and Floodplain

Key Features

Alternative B: Nature-Focused Floodplain with Habitat Island

Key Features

Continue the Conversation

Downstream Segment

Bible Park

Project Wide