Lake with dam that has branches and brush built up blocking it

Stormwater

Wetland Conversion of Upper Durant Lake

Maintaining and Protecting the Nature Preserve

There is a 6-acre upper lake at Durant Nature Preserve. Water leaving the upper lake flows through a concrete spillway (over an earthen dam) and along a 100-foot-long channel to the lower lake.

In 2013, an engineering firm contracted by the City of Raleigh deemed the dam and spillway of the upper lake to be deficient and in need of repair. A study was conducted to explore options to maintain the area and protect the preserve.

View the Upper Lake Study Report

Project Details

 
Type:
Lakes, Streams, and Dams
Budget:
3 million
Project Lead:
Stormwater Management
Contractors:
WK Dickson (Design)

Contact

 

Emily Smull, PE
Project Manager
919-996-5582

Lead Department:
Engineering Services
Participating Department:
Parks, Recreation and Cultural Resources
Service Unit:
Stormwater

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Strategy

With the study phase complete, we considered multiple alternatives that were shared with the community and citizen advisory boards. 

Approved Recommendations 

City staff recommended converting the upper lake at Durant Nature Preserve to a tiered wetland. This recommendation comes after completing the study and getting feedback from stakeholders and the community.

In April 2021, Raleigh City Council approved moving forward with the tiered wetland. We are expecting to start the design phase in mid-2022. We'll keep you updated on any changes.  

Getting Feedback 

Virtual Meeting Resources 

Planning

During this study, we evaluated the lake’s physical, biological, and chemical conditions. Then we looked at how we can change the lake area to:

  • Create a better ecosystem;
  • Provide a variety of landscape features at the lake; and,
  • Improve the visitor experience.

Work for the study took place between 2017 and mid-2019. View the report.

 

Lead Department:
Engineering Services

Design

The project is currently in design Phase 1. During this phase, the team will identify the type of wetland best suited for the site. We will likely use natural materials such as rocks and logs to control the wetland habitat. Native materials will be designed to mimic natural features and minimize maintenance requirements.

Current Project Status

Fieldwork

In February 2023, survey crews were on site at Durant Nature preserve, collecting topography and stream cross sectional data, to support future engineering analysis and design. Geotechnical investigations were also completed in late February 2023. Survey collection and geotechnical investigation is now complete – all trails are open.

General fieldwork is ongoing. You may see crews on site, analyzing stream sediment data and collecting existing vegetation information, throughout Spring 2023.

Lead Department:
Engineering Services

Construction

Phase details coming soon.

Lead Department:
Engineering Services

Complete

Phase details coming soon.

Lead Department:
Engineering Services

Schedule

Date Activity
Winter/Spring 2023 Existing conditions data collection
Spring 2023 1st Community engagement meeting (date TBD)
Spring/Summer 2023 Design alternative development
Fall 2023 2nd Community engagement meeting (date TBD)
Late Fall 2023 Preferred wetland design alternative selected
Late 2023 Phase 2 Design plan development begins

Alternatives

Here are a few options for the lake based on study findings:

  • Keeping the shape of the lake the same with a new spillway structure and lower water surface level;
  • Converting the lake to a wetland system to improve water quality and/or wildlife habitat (includes partially breaching the dam); and,
  • Restoring the lake to a natural stream and floodplain (includes completely breaching the dam).

Each option was scored and ranked. The wetland alternative ranked the highest. The restoration ranked the lowest. Changes to the lake will also follow requirements from our lake policy

View the Upper Lake Study Summary Presentation

The Study

The purpose of the study is to come up with alternate solutions to maintain the area and protect the preserve. We started studying the lake’s condition in 2017 focusing on:

  • The history of the lake and surrounding area;
  • Mapping the lake’s structures, shoreline, and sediment;
  • Biology of the streams flowing into and out of the lake; and,
  • Chemical properties of the lake’s water and soil.

The study is made possible through a grant from North Carolina Land and Water Fund (formerly North Carolina Clean Water Management Trust Fund).

History

We acquired Durant Nature Preserve in 1979. The 237-acre preserve has two lakes, which were constructed around 1950. The lower lake is used for recreation (boating and fishing) and nature education. The upper lake is used for nature walks and wildlife viewing.

We evaluated the lakes’ dams and spillways in 2013. Results showed that we’d have to repair both lakes so that they continue to function properly. We started studying the upper lake in 2017. In mid-2019, we repaired the lower lake’s dam and spillway.