Environment

In the 2015 Paris agreement, countries committed to implementing measures to reduce greenhouse gas emissions to limit global warming. For the maritime industry specifically, the International Maritime Organization (IMO) has proposed measures for energy efficiency of vessels and candidate measures regarding fuel choice and speed optimisation. This article aims to contribute to the latter by showing how logistical simulations can be used to optimise fleet operations. We will illustrate this in the form of a conceptual case using one cutter and a range of barge fleets. Running simulations with all possible fleets, we will demonstrate the value of extra energy-based alternatives to challenge the fastest, cheapest and most flexible alternatives.

Numerical models are often used to predict the magnitude and behaviour of dredge plumes to help assess and manage any environmental risks. To provide a realistic prediction of plumes resulting from dredging, numerical models require information on the rate at which sediment is suspended by the dredging, along with the characteristics of the suspended sediment. Previous investigations have shown that in the marine environment, fine-grained sediment suspended by natural processes and dredge-related activities are typically present as aggregated particles known as flocs. This article considers the importance of including the process of flocculation in dredge plume models.

Marine dredged sand and gravel make an important contribution to regional supplies of building materials used in England. Marine aggregate dredging however, is known to result in effects to the receiving environment which, if not properly controlled, could cause adverse impacts to a wide range of receptors. As the marine area around England gets busier, competition for space comes with regulatory challenges and an integrated marine management approach that uses a robust planning system is required. This article discusses the regulation of aggregate dredging in England and provides an overview of the sector’s importance in providing primary aggregate.

Green solutions in ports, waterways and coastal projects have increasingly become available thanks to many years of research and pioneering efforts in practice. These sustainable and/or nature-based solutions have shown to be good alternatives for classic solutions, but application is far from mainstream yet. One of the major hurdles is the lack of access of private capital to finance these kinds of solutions despite the strong interest of capital markets in green infrastructure opportunities. Identifying the hurdles and paving a way forward to overcome these hurdles could therefore help to increase the uptake of those green solutions.

The planet is facing enormous challenges caused by human activity, increasing the vulnerability of communities and ecosystems to the forces of nature. This is worsened by the effects of climate change, which is threatening the world’s coastal defences. Van Oord has responded to these challenges by developing the Climate Adaptation Action Plan. The plan is designed to encourage meaningful dialogue between stakeholders in order to provide ready-to-scale marine solutions that help increase the resilience of the communities and ecosystems of coastal areas.

The use of nature and natural processes is an innovative way to increase water safety and create added value through nature development and recreation. This exploratory study provides an initial inventory of the impact and costs of existing Building with Nature projects in the Netherlands. It also includes an analysis of the decision-making process in choosing this type of project and identifies success factors. Building with Nature projects deliver added value but often also involve additional costs compared to traditional reinforcements. These costs give an indication of what we as a society are prepared to pay for the development of nature and recreation as part of hydraulic engineering projects.

Climate change and increasing environmental damage are demonstrating the urgency of transformation to a sustainable global economic model. The implementation of the sustainable development concept tends to narrow to integrating environmental, social, and economic concerns in the decision making. In economics, the definition of such concerns is an externality that represents the divergence between social and private costs. This study investigates the available sustainable asset valuation methods that can include the externalities materialised in maritime infrastructure projects and compares them based on economic, social and environmental criteria.

In today’s world, expectations for sustainable practices are fast becoming the norm. Countries, the public and communities are requesting transparency, the application of higher environmental standards and involvement in decision-making processes when new developments in a marine environment are proposed. Marine infrastructure projects not only require environmental permits and works licences to be in place, they also need a Social Licence to Operate (SLO). This article describes the social licence in this fast-changing context of information and technology, and explores tools that can be used to develop a ‘responsible project’ and provide a successful and sustainable outcome for society and the environment.

A full consideration of ecosystem services (ES) impacts, interactions and improvements can result in more sustainable and adaptive solutions for dredging and marine construction projects. Furthermore, the benefits can be translated in monetary terms, providing returns on investment and highlighting the links between ecology and economy. For some however, the ES concept is too theoretical. This article seeks to show how the ES concept can actively be applied at any point during a project and the benefits of doing so. Its purpose is to provide a framework for integrated and interdisciplinary thinking throughout the different steps of the project cycle.

As increasing greenhouse gas (GHG) emissions contribute to global warming, it is becoming more important to consider the carbon footprint of hydraulic engineering projects. This carbon footprint is more complex than previously thought however, as it can also include the carbon dynamics of the sediments from which projects are built. The purpose of this study was to provide a first approximation from sediment-related GHG emissions of dredged sediments. Using the case study of the clay ripening pilot project (‘Kleirijperij’) in Groningen, the Netherlands, one phase of sediment processing was examined: the ripening of dredged sediments for use as a clay material in dyke construction.

The development of a new marine project demands a system approach in which all aspects, including technical, economic, environmental and social, are considered and integrated equally and at an early stage. While insufficient information may be available to make informed decisions, choices need to be made to progress a project, assess impacts and risks, and engage stakeholders. This article explores the case of a new port terminal in Amatique Bay, Guatemala. A method was developed to assess, at an early stage, the potential negative impacts on seagrass habitats from the disposal of dredged material at different locations, while having limited real-time and location-specific information at hand.

Taking a fresh look at traditional, unsustainable coastal defence methods. A pioneering project discovers some inspiring concepts, including using biogenic reefs for ecosystem-based flood defence.

‘It’s clear that the solutions that we employed in our approach to engineering in the 20th century are not aging well.’ As National Lead for the Engineering With Nature initiative, Dr Todd Bridges discusses how we must have a diversified solution set in which nature is a part of the solution.

Over the past decades, there has been a growing interest in exploring innovative ways to minimise the environmental footprint of coastal developments and in nature-based approaches for shoreline protection. At Mubarraz Island near Abu Dhabi (UAE), an international oil company beneficially reused ~12 million m³ of dredged material to protect pipelines, construct a causeway and create mangrove habitat to manage coastal erosion. This ‘Working with Nature’ approach has provided a cost-effective nature-based solution for shoreline protection, with added benefits for biodiversity conservation.

At Deltares in the Netherlands, a research team is developing a portfolio of technologies dedicated to the management of the finest and most challenging fraction of soft sediments. These technologies may unambiguously be called nature based because they make use of natural processes to enhance dewatering and strengthening, induce flocculation and the settling of fines, and protect the muddy bed from erosion.

Managing sediments, especially from dredging, is important for the management of estuaries and coastal areas. When implemented in the right way, a sediment management strategy can be qualified as a nature-based solution as it uses the physical processes of erosion and sedimentation to create added value. There is a need for an evaluation of sediment strategies and the habitats that are created for a wider range of objectives than only biodiversity and nature conservation. The concept of ecosystem services provides this broader framework.

At present too little use is made of the opportunities that the design and construction of land reclamation offer for the underground storage and recovery of fresh water. The managed aquifer recharge systems in the coastal dunes of the Netherlands are a good example of successful subsurface water storage. And it is to be expected that the sandy deposits of land reclamations could serve a similar purpose. This in turn will contribute to a sustainable development of land reclamations.

‘Water is more than a toilet, tap, dam, dyke or levee, it's an enabler.’

Dredging is essential for the maintenance and development of ports, harbours and waterways to allow for safe navigation, remediation and flood management. The process, which relocates large volumes of sediment, can be accompanied by the release of suspended sediments into the water column referred to as sediment plumes.

Can nature-based solutions be mainstream solutions? Nature-based solutions have obvious advantages but have not been embraced at wider scale. The barriers which can hinder wide-scale application and the topic’s relevance to the dredging community are discussed.

The Bacton Sandscaping scheme is a large-scale beach nourishment designed to protect the Bacton Gas Terminal from cliff and beach erosion while also reducing flood and erosion risk to the communities of Bacton and Walcott, buying the time they need for adaptation to coastal change.

This study examines which and, if possible, how much more ecosystem services are provided by the most recent nature inspired coastal protection project Prins Hendrik Zanddijk, in comparison with a traditional concrete and asphalt construction.

After 30 years at Witteveen+Bos, Henk Nieboer has moved on from the engineering and consultancy firm to focus his expertise into his current roles as director of EcoShape and founder of Adaelta.

CEDA’s Working Group on Beneficial Use aims to inspire sediment stakeholders and practitioners by describing the importance of sediments in the context of sustainable development and sharing a curated selection of case studies.

Following the Building with Nature concept, a pilot study was conducted introducing finegrained dredged sediments as a semicontinuous source of mud into a shallow tidal channel, naturally dispersing sediment to nearby mudflats and salt marshes.

In collaboration with the Natuurmonumenten (the Dutch Society for the Preservation of Nature), Boskalis constructed the Marker Wadden. The archipelago situated within the Markermeer enables processes which revitalise the natural ecology.

Popular instruments in the field, optical backscatter instruments (OBS) are used to measure suspended sediments. The sensitivity of OBS measurements in relation to grain size and the applicability of OBS measurements in mixed sediment environments is analysed.

Ecologist Patrick Meire has been researching the Scheldt for decades in the hope of implementing solutions which undo the damage caused by humans, industry and natural processes.

To connect Scandinavia with Germany, the world’s longest immersed tunnel will be built. The Fehmarnbelt will close a major gap in the European transport network while fostering the development of new nature and recreational landscapes.

Dredging activities often result in the suspension of sediment into the water column in the vicinity of the activity. Sediment release to the aquatic environment and the effects of this release are often the prime environmental concern associated with dredging.

Randle Reef at Hamilton Harbour, an Area of Concern (AOC), is the largest site in Canada contaminated with Polycyclic Aromatic Hydrocarbons (PAHs). A collaboration of municipal and federal entities is working on remediation measures.

ReefGuard, a mobile coral breeding facility provides a highly controlled environment to aid in integrating the breeding and outplanting of corals. This article gives a detailed look into how proven small-scale coral breeding techniques can be scaled-up and applied in practice to promote environmental gain around marine infrastructure projects.

The sediments in Valdemarsviken fjord in Sweden were contaminated with chromium from the discharge of untreated wastewater from tannery operations decades ago. The contaminated sediments were dredged, dewatered, solidified and placed as a engineered fill in a nearshore area.

Maintenance dredging is required in many estuaries worldwide to provide access to ports and inland waterways. A newly developed dredging module is able to capture the two fundamental processes necessary to model the long-term impacts of dredging on turbidity.

Building with Nature is an innovative approach that combines natural processes with innovative engineering methods to realise sustainable projects. Permeable dams are being utilised as part of a Building with Nature solution to help restore the eroding mangrove-mud coast of the Demak district in central Java, Indonesia.

Underwater sound from anthropogenic sources and its potential adverse effects on the marine environment is a topic of much global interest. This article gives an overview of known sound source levels for various dredging equipment and activities and describes a method used to extrapolate source levels.

A case study of a tidal marsh restoration project at the Polders of Kruibeke in Belgium shows how an Ecosystem Services assessment can reveal otherwise hidden benefits.

As mounds of dredged material placed upriver are dispersed by the river’s current, an island with enriched wildlife has emerged.

Revitalising and redesigning inland water transportation routes and recreational waterfronts transforms them into vital and viable economic and social engines.

Marine fauna is sensitive to underwater dredging sounds. Scientific research indicates that inducing the fauna to leave an area temporarily before the start of a project minimises serious impacts. And the marine life returns when the dredging is finished.

How to protect the environment of the Texas Gulf Intracoastal Waterway and preserve a crucial economic link as well.

Reducing the carbon footprint of dredging operations is a major industry concern – and the solution starts with the design phase and continues through the whole lifecycle.

With dredging responsibility for 11 municipalities along the environmentally sensitive Tagus estuary, the Port Authority of Lisbon needed an integrated strategic dredging plan. After detailed studies, they got it.

Is it possible for an in-site disposal area to be environmentally and economically preferable to an offshore disposal site? Real-time monitoring says yes, there are numerous benefits to the disposal of dredged material in-site.

To realise a state-of-the-art cruise terminal, a comprehensive environmental mitigation plan relocated some 150,000 soft and hard coral, sponges and numerous sea urchins, sea cucumbers, hermit crabs, conchs, sea stars and lobsters.

The Fehmarnbelt Fixed Link connecting Scandinavia and continental Europe will most likely become a tunnel rather than a bridge, but how it will be dredged is still to be determined.

Worldwide the total area of tidal flats is decreasing as a result of sea level rise, subsidence by gas extraction and erosion initiated by artificial constructions. This IADC Award winning paper examines whether nourishment programmes might be part of the solution.

Dredging for a new port complex in a remarkable, protected marine environment required adherence to very specific thresholds and an intensive Environmental Management Plan (EMP) that included mobile monitoring as well as daily visual observations of turbidity levels around the dredging works and the disposal zone.

Models created by researchers using innovative software have been tested and validated by monitoring trailers during dredging operations.

Decision-making for infrastructure depends on a mix of local culture, the political situation and uncertainties related to the project’s complexity. To explain the process of gaining the confidence of stakeholders, two cases of “Building with Nature” in the Netherlands are presented.

The Stanford University Policy and Engineering Responses to Sea Level Rise (SUPERSLR) project is examining various solutions and the constraints for worldwide ports which could face the challenges of sea-level rise all at roughly the same time.

A state-of-the-art 3D plume model, used at the Ras Laffan Port Expansion project, simulates alternative disposal scenarios and helps develop Safe Disposal Maps.

What is economically and environmentally better: obtaining sand for beach nourishment from an on-land quarry or from marine banks at sea?

EU environmental law and international conventions are not always compatible. The European Dredging Association makes its case on when and why dredged material should not be considered waste.

This article covers the initial environmental examination and the development of mitigation measures against adverse impacts of physical works. Detailed investigations of water and groundwater, and sediment and soils support the assessment, backed by field surveys.

There are two types of driving force that urge us to assess the effects of dredge-generated plumes, a genuine concern for the environment and the regulations that forbid us to dredge unless we can demonstrate that harm will not be caused to the environment.

The Niger Delta is located in the southern part of Nigeria bordering the Atlantic Ocean. It is a floodplain of over 70,000 sq km. The delta is poorly serviced by roads and is made up of meandering creeks that are highly silted up.

To be successful, a modern port must pay attention to the public's justifiable concerns about environment.

"Coevolution" and the "Triple P Performance" principle are applied as guidelines for modern companies - including the dredging industry - to create legitimacy for growth.

In this new study, Cochin, the second largest harbour on the west coast of India, is thoroughly examined for environmental impacts during and after dredging.

The winner of the 1996 IADC Award, this paper describes one of the recent dredging techniques tested on the Ketelmeer and now being used in the Port of Nieuwpoort, Belgium.

Two main classes of pollutants, heavy metals and organic micropollutants, are evaluated to determine the extent of environmental risks when dredging and how these can be controlled.

The Fact Sheet "Creating a Sustainable Marine and Freshwater Infrastructure” describes how to achieve dredging projects that fulfil primary functional requirements while adding value to the natural and socio-economic system.

The Fact Sheet "Beneficial Use of Dredged Material" describes methods and answers questions about how to deal with large quantities of sediments in relation to dredging projects and ecological developments

The Fact Sheet "Environmental Monitoring” describes the methods used to alert dredging contractors to environmental impacts so they can be addressed quickly.

“Facts About Turbidity & Dredging” describes the characteristics of turbidity and the importance of measuring and monitoring turbidity during dredging.

“Facts About Ecosystem Services & Dredging” describes how the value attributed to ecosystems and to dredging projects can be compared and evaluated.

“Facts About Dredging Management Practices for the Environment” describes how to create management guidance for improving environmental performance.

“Facts About Adaptive Management” describes how monitoring at intervals during a project supports decision-making process to modify operations as needed.

The book Dredging for Sustainable Infrastructure gives state-of-the-art guidance on how to design, implement and manage a water infrastructure project with a dredging component.

The book Dredging for Sustainable Infrastructure gives state-of-the-art guidance on how to design, implement and manage a water infrastructure project with a dredging component to project owners, regulators, consultants, designers and contractors.

The report provides the general concept of ecosystem services and the overall considerations on its use in the context of dredging projects.

A concise overview of dredging’s effects on the environment, aimed at a broad audience.

Various risk-based methods are used to assess environmental impacts from dredging and dredged material management activities.

Information and recommendations regarding Confined Disposal Facilities, including the management of contaminated dredged materials.

A concise guide to support and explain the management of dredged material.

During planning, design and operations of port development, these economically and socially sound actions can minimise impacts on the coastal zone.

This book is out of print and has been replaced with an updated book. To read more about Dredging for Sustainable Infrastructure, click here.

On 6 June 2018, sixty young professionals from IADC’s member companies came together at Hilvaria Studio’s for the association’s second annual networking event, Peering into Dredging’s Future.

Through his presentation “Climate change: business challenges and opportunities of dredging”, Serge addressed innovations which deal with the obstacles of energy transition, climate change effects, population growth, resource depletion, loss of biodiversity, pollution.

This video relates to the Terra et Aqua article: 'FaunaGuard: a scientific method for deterring marine fauna'. Please use the following link to download the article: http://www.iadc-dredging.com/227/terra-et-aqua/issue?id=153?id=153 Publishe

Because dredging projects impact a wide variety of stakeholders, a fundamental knowledge of the interaction of ecology and dredging is to everyone’s benefit.