Great Lakes Neighborhood Stormwater Improvements: 60% Design Survey

This is the project area as identified in the 2020 Stormwater Master Plan. This area reflects the the subbasin where all water that falls within this area flows to a common point (Glenn Creek through Waddell Park).

60% Design Plan of Waddell Park

Stormwater Outfall and Forebay within Waddell Park.

Please note: Rendering reflects conditions during wet weather events (typically pond and pipes will be dry). Rendering is intended to show the concept only – the overflow weir will be concrete wall with a stone veneer with a concrete bridge in front of the structure as shown in aerial view. 

Following positive feedback at the conceptual meeting, we have progressed discharging flow from the stormwater pipe network into a forebay in Waddell Park, which will temporarily hold water during storm events to settle sediment and debris and reduce stream velocities to protect the stream. This small pond-like structure will be typically dry. During wet weather events, this area will receive stormwater flows, which will discharge to the existing stream. Following wet weather events, the forebay will be designed to drain within 48 hours to prevent mosquito breeding.

The alternative to this configuration would be piping all the way to the culvert at the end of the park to keep stormwater underground. 

The City of Decatur is seeking to increase stormwater storage where feasible as part of the implementation of the Stormwater Master Plan for climate resiliency. The largest opportunity for increasing stormwater storage in this area is through a bioretention practice (engineered soils with high porosities and plantings) on Champlain Street and part of Geneva Street along Waddell Park. Based on previous input, we have also incorporated a sidewalk over the practice to increase sidewalk connectivity to the park. It should be noted that this will remove parking on this section of Champlain Street and around the primary entrance to the park.

There are currently three stairways into the park on Geneva Street, some of which are in poor condition. In this design, we are proposing to enhance the main entrance stairway on the corner of Champlain Street & Geneva Street, demolish the middle staircase and restore into a construction/ maintenance path, and replace the third staircase which is currently in poor condition. 

Existing path in Waddell Park

This plan has also investigated improvements to the trail network within the park. We have options to keep the path as informal (as shown in existing image) or to formalize the path with a porous aggregate (shown below).

Rendering showing hardened, porous aggregate path

Preliminary planting plan for Waddell Park (Featured plantings are example species and do not reflect the full palette of plantings)

This project will include invasive species plant removal. In order to prevent the invasives from returning, it is important to plant native species in their place. Based on the conditions within the park, we will be identifying planting palettes for bioretention, upland, riparian, and forebay areas.