International Dredging Review

International Dredging Review

Recently both the Mississippi River and the Great Lakes got report cards of sorts – the America’s Watershed Initiative published its Report Card for the Mississippi River in October 2015 and the Great Lakes Restoration Initiative Report to Congress and the President was published in July.

The Great Lakes Restoration Initiative (GLRI) which launched in 2010 has accelerated efforts to protect and restore the world’s largest freshwater system and the program has been successful in large part with help from dredging projects.

During the first five years federal agencies and their partners completed all of the cleanup required to delist five Great Lakes Areas of Concern (AOC) and to formally delist the Presque Isle Bay AOC. Before GLRI only one AOC was cleaned up and delisted.

GLRI funding was used to complete cleanups at six AOCs: Ashtabula River Ohio; Deer Lake Michigan; Presque Isle Bay Pennsylvania; Sheboygan River Wisconsin; Waukegan Harbor Illinois; and White Lake Michigan. Out of all the areas considered in the study AOCs received the largest portion of funding (from approximately $147 million in 2010 to $106 million in 2015).

From 1997 to 2013 EPA and its partners have remediated approximately 13.3 million cubic yards of contaminated sediment from the Great Lakes basins.

Dredging also is often part of habitat and wildlife protection and restoration and the GLRI report said more than 100000 acres of wetlands and 48000 acres of coastal upland and island habitat were protected restored and enhanced.

To guide the first five years of the program the GLRI Action Plan I set forth goals for each area. The action plan objective for AOCs was delisting five by 2014. While all the management actions necessary for delisting seven AOCs have been completed the monitoring required to verify all the conditions and formally delist the AOCs will take additional years the new report noted.

In September 2014 the initiative released the Great Lakes Restoration Initiative Action Plan II which will guide progress through 2019 and which calls for the delisting of 10 additional AOCs – at Buffalo River Clinton River Grand Calumet River Manistique River Menominee River Muskegon Lake River Raisin Rochester Embayment St. Clair River and St. Mars River.


America’s Watershed Initiative (AWI) is a collaboration including public and private sector leaders from the 31 states of the Mississippi River Watershed finding solutions to the challenges facing the Mississippi River and the more than 250 other tributaries that flow into it. AWI says those challenges are large and growing and the letter grades for various categories highlight the need for improvements. In October AWI release its report card for the Mississippi River.

As the report states “The goal for the report card is simple – provide decision makers watershed leaders and the public with easy to understand information about the state of the watershed’s health to aid them in developing a collaborative approach to managing America’s Watershed.”

Over the course of two years a working group developed the report card with input from leaders stakeholders and experts from more than 400 businesses organizations agencies and academic institutions from every major river basin the watershed. The group developed a draft in 2014 for review soliciting feedback and input before this most recent final report was released.

The report card results were calculated for the Upper Mississippi River Ohio and Tennessee rivers Lower Mississippi River Arkansas & Red rivers and Missouri River basins. Considering six goals – ranging from supporting commercial navigation ecosystems and economies and providing reliable flood control and risk reduction and recreational opportunities to maintaining clean water – the report card measured the status and trends of the six goals throughout the Mississippi watershed. Each category received a letter grade based on a 0 to 100 range. Each letter represents 20 points on the scale meaning a grade A represents a score of 80 to 100 and an F represents a score of 0 to 20.

Overall water quality for the Mississippi River Watershed was graded at a C-. The habitat index which assessed the condition of stream and river habitat in the ecosystem was graded for the whole watershed at a C+. Issues with water quality and habitat always greatly affect projects – often the timeline and cost driving them up.

Wetland loss is an issue in many places and along the Mississippi River and as the report noted it has been exacerbated by infrastructure (navigational flood control and recreational) which prevents a necessary natural connectivity between the channel and upland areas to regulate nutrients and sustain organisms. In 1988 the federal government adopted a set of regulations and initiatives with the goal of “no net loss” for wetlands. An indicator looking specifically at coastal wetland change graded the Mississippi River Watershed at a D-. A net loss rate of zero (no net loss but no recovery) would earn a C grade on the report card.

Different programs in each of the basins are actively working on ecosystem restoration but there is much work to be done. Dredging can be an important part of wetland restoration by beneficially placing sediment. A poor score in wetland changes could mean more dredging work for those areas.

As the report says: “Sediments sustain coastal wetlands.” New wetlands balance losses from erosion and are created from incoming sediment to the existing coastal wetlands. Manmade reservoirs along the Mississippi River and its tributaries built in the 20th century have reduced the amount of overall sediment carried by the river. Levees further restrict the amount of remaining sediment that is delivered to coastal wetlands. As the report explains most of the sediment carried to the Gulf of Mexico through the Lower Mississippi River is carried out through its mouth in the Bird’s-foot Delta and deposited in deep water where it is no longer available to nourish coastal wetlands. “This situation is a direct result of engineering the river to maintain high-flow water velocities through the mouth which reduces the dredging needed to maintain a navigable channel” the report said. Yet dredging is also a solution here.

The rate of wetland area loss has decreased from historically high rates but loss continues. While new wetland area is being added at the outlet of the Atchafalaya River a distributary of the Mississippi that delivers sediment to shallow inshore waters the real promise for wetland creation is the beneficial use of sediments from elsewhere in the river. “If these trends continue the overall balance soon could shift to a net increase in wetland area” the report said.

As an example of how sediments are rebuilding wetlands on page 24 you can read about some projects in Louisiana where coastal wetland loss is most serious. The state has long been battling wetland loss and the Coastal Wetlands Planning Protection and Restoration Act (CWPPRA) Task Force celebrated its 25th anniversary and its commitment to coastal restoration. The event highlighted a number of projects that were part in restoring more than 100000 acres of wetland since CWPPRA’s inception. The event also had a tour of the Caminada Headlands restoration project where Weeks Marine is underway in Phase Two. Read more about the event and highlighted projects on page 24.