Posted on June 24, 2024
The project goals include maintaining a navigable waterway and wetland restoration.
This is a collaborative project, drawing on the expertise of two teams – the Wetland Monitoring and Assessment Program and the Shoreline and Waterway Management Section – in the DNREC Division of Watershed Stewardship.
The project area is in the Inland Bays region of Sussex County, located on the east side of the Town of Millsboro. The beneficial use project site can be found in the upper reaches of the Indian River, along pre-existing wetland property owned by the Town of Millsboro.
Since a previous dredging project in the Indian River in 2019, the channel in this area has decreased due to sedimentation and shoaling.
Announcements
The dredging process will begin July 1, 2024 and continue until completed.
Work will occur Monday through Thursday. Access to channel will be extremely restricted.
Within the project area, there is limited access to the channel due to extreme shoaling. Boaters should be aware of the tides when navigating through this area. It is not advised to navigate this channel at low tide or during the dredging project.
This project is funded through DNREC appropriations in the fiscal year 2023 budget.
Beneficial Use
Traditional land disposal of dredged material is difficult to plan and maintain. The Division of Watershed Stewardship has researched alternatives for sediment placement.
Over the last several decades, beneficial use of dredge material has been investigated as a method to restore degraded or submerged tidal marshes.
Major goals of this project are to demonstrate techniques for using dredged material for wetland restoration, to improve navigability within the upper reaches of the Indian River, and to help build program capacity for future use of dredge material for environmental benefits.
Project areas: 8 acres of Phragmites treatment and 7 acres of marsh recreation in the tidal wetland
Project Overview
DNREC’s Shoreline and Waterway Management Section uses a data-based method to prioritize dredging projects. It has identified the Indian River as a top priority for dredging. This method includes surveys of residents and users of the waterway, channel depth, boater safety and other environmental considerations.
Traditional maintenance dredging of the Indian River to maintain navigable channels requires the disposal of dredge materials in upland containment units which are limited by size and access.
As an alternative, DNREC will use dredged sediment as a resource to restore wetlands adjacent to the dredging area. Beneficial use of dredge material is a wetland restoration strategy that can help stabilize sensitive shorelines that ultimately reduce erosion and storm damage.
The project aims to remove up to 40 thousand cubic yards of sediment from Indian River over two years and to restore 15 acres of tidal wetlands on Town of Millsboro property through wetland recreation and invasive Phragmites treatment.
History of coastal wetland loss and shoreline comparison over decades at the Millsboro project site
The project will restore native high marsh by treating invasive Phragmites (Phragmites australis). It will build a new marsh platform and recreate a former low marsh using dredged sediments from the upper reaches of the Indian River and seeding of native plants.
Once the project is complete, the restored wetland will be monitored for three to five years.
State and federal permits required for the project to restore wetland habitat using dredge material have been acquired.
DNREC has engaged Anchor QEA to provide engineering services and limited construction oversight.
The Town of Millsboro and private landowners are also supporting partners of the restoration project.
Project Goals
The goals of this project are to demonstrate techniques for using dredged material for wetland restoration and to improve navigability within the Indian River. This project will use lessons learned from DNREC’s beneficial reuse project at Piney Point, as well as lessons learned from projects in other states. Specifically, the project goal is to demonstrate how dredged material can be used to restore former wetland habitat that has become unvegetated and submerged.
Additional important goals of the Millsboro project are:
- To provide relief from extreme shoaling over the next two years through dredging the primary channel
- To recreate a former, submerged tidal wetland with the reuse of dredge materials
- To replace lost wetland habitat to stabilize shorelines and reduce erosion
- To restore areas invaded by Phragmites to native marsh plants
- To build capacity within DNREC for additional dredge and restoration projects
Project Benefits
This project will provide multiple benefits.
For the Town of Millsboro:
- To help protect adjacent infrastructure from flooding, storm damage, and erosion
- To alleviate navigational hazards
- To increase coastal resilience in the face of storms and sea-level rise
- To provide improved wildlife habitat and water quality
- To enhance recreational opportunities
Helping meet Delaware Wetland Management Plan goals:
- To protect the remainder of the wetland habitat, several important properties, and surrounding infrastructures from impacts of sea level rise and other environmental stressors
- To help DNREC identify alternative disposal options to better benefit the citizens of Delaware
- To address regional priorities for wetland restoration and sediment management
- Project Timeline
The construction portion of the project must be completed by the end of February 2025.
Permits for the project specify specific time periods during which the work will not impact any vulnerable species. Work is restricted to only those times of year.
For more information on the project, please contact Kathleen Bergin at 302-855-7290.
