Working with Nature Project Overview

Project NameCountryStatusObjectiveDescriptionDetail
The Seine-Scheldt project in Flanders - The lock of HarelbekeBelgiumThe Seine-Scheldt project aims to connect the Seine basin in the Paris region with the Scheldt basin in the region of Antwerp-Rotterdam, for vessels up to ECMT-class Vb (4500 tonnes). In order to achieve this by 2016, the Belgian region of Flanders is preparing navigability enhancements of the river Lys, which currently allows vessels up to 2000 tonnes. In the city of Harelbeke this calibration implies the construction of a new lock and weir together with the restoration of fish migration.Due to the urban environment, the project site has many conflicting goals that highly increase the complexity of the overall project. In order to achieve an integrated project that offers a best fit solution Waterwegen en Zeekanaal NV decided to launch a “Design & Build”-procedure (D&B) for the project in Harelbeke. The contract specified the goals for the project, ranging from spatial quality over technical, hydraulic and nautical merit to aspects of nuisance during execution, durability of the design, planning and overall management. Since the existing weir also needs to be replaced, the aspect of water management and flood control became a very important factor. To solve the problem of fish migration along the river Lys, the contract also asked for the design of a fish ladder to bypass the weir. In general action is undertaken to increase the ecological potential of the river Lys in the urban area of Harelbeke. Natural landscaping and environmentally friendly river banks are only two examples of achieving this. For the design of the overall project in Harelbeke the emphasis was laid on minimising the total Life Cycle Cost of the infrastructure. In order to do so, a hydraulic actuator was installed to achieve an energy neutral project. This actuator serves a double purpose: in periods of high flow the actuator generates electric energy and in dry periods the actuator can pump up the water losses of the lock so that navigation can still be guaranteed. Other important factors in Life Cycle Costing are the cost of downtime of the system and the cost of maintenance. Since the D&B contract lacks the maintenance factor as an implicit quality control, the importance of durability in design could not have been set high enough.Details
EMERHODE project (Efficient, Multimodal, Economy, Hydraulic, Opportunity of Development for Seine Estuary) (Candidate)FranceThe project has 3 key objectives : - to improve road and railway traffic fluidity in the industrial zone : a new canal will create a extra and shorter way for barges to go in and out of the port of Le Havre, and will avoid the numerous manoeuvres of the 5 mobile bridges on the existing canal. - to increase the surface of the port industrial zone, up to the northern bank of the new canal - to improve the management of the existing nature Reserve, on the southern bank of the new canal. The project consists of four main parts : - construction of a new canal approximately 4 km long and 120 m wide, with vertical berths, - extension of the industrial zone (400 ha maximum), backfilled with the dredged material, - restoring of the existing roads and railway tracks, with a new layout not crossing the nature reserve, using 2 mobile bridges high above the new canal - environmental measures as hydraulic feeder (to maintain the water table level), maybe extension of the intertidal zone in the estuary, mitigation measures. Details
Creation of a new tidal area Spadenlander Busch / Kreetsand in the context of the Tidal Elbe ConceptGermanyTo safeguard seaward access of the Port of Hamburg the Hamburg Port Authority (HPA) and the Federal Waterways and Shipping Administration set up an innovative concept for a sustainable development of the tidal Elbe River. The objective is to dissipate tidal energy and decrease flood current in order to reduce upstream sediment transport and dredging necessities. HPA is presently creating a new tidal area which is suited to moderate tidal action and also to serve nature conservation objectives.As a pilot project for the creation of new shallow water areas the Hamburg Port Authority (HPA) will open up an area of 30 ha for the tides directly in Hamburg and thus create additional 1 Mio m³ of tidal volume. Although the dyke in front of the so called Spadenlander Busch/Kreetsand area was realigned already 10 years ago, the present foreland is not subject to the daily tides. The excavation of 2 Mio m³ of soil will allow free oscillating tides and set the stakes for future developments. The soils consist of natural ground and filled up material with a different degree of contamination. Roughly one third cannot be re-used and has to be brought to disposal sites. Large parts of the residual soil will be used in upcoming harbor construction measures. A barge pier is build at the measure site to minimize truck traffic and use the shortest route to the re-assembly site. Fractions of excavated material in good conditions might also be put on the market, to be used in other construction projects. The integrative planning process has combined interests and needs from port uses, water management, nature conservation and local recreation simultaneously and advantageously. The essential planning criteria besides hydraulic efficiency and stability have been aspects of nature and landscape planning, an integrative concept of soil management as well as safety and perceptibility of the new tidal region for the public. The higher objectives in line with the concept for a sustainable development of the tidal Elbe River are a reduction of tidal range and of the tidal pumping effect, thus reducing the amount of dredged material and preventing further silting up of anabranches and side banks. This project is designed as a pilot for a new river engineering concept and as an exemplary model for future measures of similar purpose. Additionally, this practical example of sustainable river engineering shall be used to improve a new understanding of tidal systems and estuaries.Details
Flood Spillway ReesGermanyThe nearly 90o elbow of the Rhine near the city of Rees is affected by intensive river bed erosion. Decline of navigable water levels is a remarkable effect. And the location of the City forms a bottleneck for river discharge. The City is exposed to danger of severe flooding. The construction of a Flood Spillway in the sinistral floodplain will reduce risk of bed erosion, maintain navigable water levels, minimize expensive bed load supply, relieve risk for floods and enhance nature's value.On the Lower Rhine ongoing river bed erosion causes harm to navigable water levels. By constructing a flood spillway passing the sinistral floodplain at the City of Rees a significant portion of river discharge will be transferred to the spillway starting to operate at a water level threshold of Mean Water Level +100cm. Reduced flow velocity in the main river channel will reduce risk of bed erosion. At the same time the City of Rees will be relieved from danger of severe flooding as the maxium peak of highwater level will be lowered by 8cm. While realising the project intensive compensation measures are performed within the construcion area aiming at enhancing nature´s value in the floodplain and societal interation of inhabitants needs (e.g. farming, recreation, nature conservation). Details
Test stretch with technical-biological bank protection along the River Rhine, km 440.6 to km 441.6, right bankGermanyThe banks of the River Rhine near Worms are usually protected by rip-rap revetments because of heavy hydraulic impacts from navigation and wide fluctuations in water levels. The testing of technical-biological bank protection using plants or combinations of plant materials and technical structures intends to find new types of river-bank maintenance structures that consider the ecological requirements of the German Water Act (WHG) and of the European Water Framework Directive (WFD).The banks of the upper River Rhine are mostly secured by technical re-vetments that are often poor in their physical diversity and therefore lack natural riparian habitats for plants and animals in the transition zone between land and water. Since riverbank maintenance has to guarantee bank stability that ensures the safety of navigation and prevents damage to the riparian hinterland, new concepts are required which combine such safety and navigation issues with improvements of habitat and species diversity. This test stretch comprising a range of alternative technical-biological bank protection measures was established to gain practical experience with such constructions under technical as well as ecological aspects. The test stretch is divided into nine test fields. In four test fields, the rip-rap was removed above the AZW water level (~ 20 cm below the mean water level) and was replaced by new technical-biological protection e.g. willow brush mattresses, reed gabions, pre-cultivated vegetation mats on different filter mats. Along another four test fields, the rip-rap was left in place to protect the bank, but was ecologically improved with plants or other structural elements e.g. willow branch cuttings, living fascines, (dead) wood fas-cines, a shallow-water zone behind a stone wall. In one test field, the bank was left nearly without any protective struc-tures to be exposed to erosion. The results of the test that will be recorded during a 5-year technical and biological monitoring scheme can help to improve the physical-structural diversity of the river banks and are expected to improve the acceptance of waterway-maintenance works among the local residents (better recreation facilities, nature conservation…). So the results found at this test stretch will also be important for the future management practices on other German waterways, considering the ecological demands of WHG and European WFD. Details
The restoration of Salhouse SpitUnited KingdomErosion over the last 60 years caused the spit of land between Salhouse Broad and the river Bure to become significantly narrow threatening the integrity of the river bank and its riverside mooring. Now four geotextile bags of a total length of 170 metres retain 10,000 m3 of dredged sediment, forming 7,000m² of reedbed that protects the spit. The final outcome is improved navigation and a healthy reedbed, which is essential to wildlife however also form effective erosion protectionThe Broads Authority is restoring a lost reed bed and eroded strip of land at Salhouse Broad, Norfolk. (A Broad is a shallow manmade lake, conventionally dug for peat) Erosion over the last 60 years has caused the land between Salhouse Broad and the River Bure to become significantly narrow –down to 2 metres in places-- threatening the integrity of the river bank and its riverside mooring. Now 7,000m ² of reed bed is being constructed using dredged sediment retained by four giant geotextile bags. The geotubes© are fixed to locally sourced alder poles; cut from river banks near Salhouse Broad. The geotubes are being filled with 3000m ³ of sediment dredged from the River Bure to provide a 170m retaining bank. The geotubes, which are 8.5 metres wide and have a circumference of 18.6 m are big enough to drive a car through! Once filled, they will sink below the waterline and the void behind the bags will be filled in with 8000m³ of dredged sediment to restore the reed bed as it was in 1946. Dredging of the river Bure is required for navigational purposes, shoals have accumulated on the inside of bends and other slow flowing areas. Dredging to a depth of 2.00 metres below mean low water is required, allowing pleasure cruisers and sailing vessels to navigate the river. Sediment from the river Bure is being carried to Salhouse by barge where it is unloaded into a pump by an excavator. The pump, conventionally used for concrete, fills the bags via a pipeline. The use of a concrete pump is required because the sediment pumped is undiluted, in-situ sediment. Geotubes have been filled with sediment before, however not with in-situ (solid) sediment with a concrete pump under water! The surface of the geotextile bags will be planted with reed seed and rhizomes sourced from vegetation scrapes, carried out as part of reed bed management on an adjacent site this winter to help restore it as a natural reed bed. Details
Development of the 3 Meter Navigation Channel of the Middle Mississippi River, Miles 195 to 0.United StatesThe project objectives are to ensure reliable navigation depths and widths on a critical 195 mile stretch of the Mississippi River. This stretch is referred to as the Middle Mississippi River reach, between the confluences of the Missouri and Ohio Rivers. The reach is part of the upper limits of the “open river” reach, whereas the viability of navigation is not dependent upon locks and dams. A reliable channel is developed using river training structures and dredging. The development of the 3 meter navigation project of the Middle Mississippi River has been ongoing since 1890. Initially, large wooden pile dikes, willow matt revetments, clearing and snagging operations, and dredging, were all used to maintain a 1 meter channel. Eventually a 3 meter channel depth was authorized. Up until about the 1960s wood was used for construction materials, then replaced by stone. River engineering consisted of large perpendicular stone dikes for channel accretion and stone revetment for bank stabilization. In the 1980s, two endangered species, the first being a small bird called the LeastTern, and the second a fish called the Pallid Sturgeon, required river engineers to re-think their design. Rather than build traditional large perpendicular dikes, they had to come up with innovative ways to not only solve dredging problems, but create enhanced habitat for fish and wildlife. Since the mid 1980s to the present, using both large and small scale physical sediment modeling, engineers were able to design and construct a variety of rock training structures that replaced traditional structures, including bendway weirs, blunt-nosed chevrons, w-dikes, side channel enhancement dikes, rootless dikes, hard points, mutliple round point structures, and notched dikes. These structures were all designed to create environmental diversity and enhanced habitat while still being able to improve the navigation channel. In many locations, the structures have eliminated or substantially reduced repetitive maintenance dredging. Dredge cuts and dredge disposal can have an instantaneous negative effect on both aquatic and semi aquatic habitat. New structures continue to be developed in this challenging stretch of the river, with both accidents and dredging having been significantly on the decline. Details
Cleveland Harbor East Arrowhead Breakwaters Demonstration ProjectUSAThe existing East Arrowhead breakwater had deteriorated over time due to wave damage from the open waters of Lake Erie. Routine maintenance of the breakwater was needed to ensure that the breakwater served its intended purpose of preserving safe navigation in Cleveland Harbor. Objectives also are to provide features that will create habitat opportunities for Great Lakes species that would not otherwise be present and to help reduce beneficial use impairments within the Great Lakes region.The demonstration project involves modifying the design of the standard concrete toe blocks used for breakwater maintenance to provide features that will create habitat opportunities for aquatic life. The repair section is 136’ long (41 m). Seventeen toe blocks were installed and monitored, each block having a dimension of roughly 8’ x 5’ x 4’ and each weighing about 10 tons (9.1 metric tonnes). The study is examining ways in which substantially more habitat surface can be created on the breakwater by modifying the shape and surface texture of the toe blocks. Three separate block modifications are being investigated to determine how they perform as habitat: (1) a protected indented shelf to serve as fish refuge and potential spawning areas: (2) dimpled block surface texture to provide invertebrate habitat; and (3) grooved block surface texture to provide invertebrate and juvenile fish refuge. Based on monitoring results, textures found to best serve as habitat to native species will be in the future incorporated more broadly across navigation repair and maintenance projects. The Buffalo District of the US Army Corps of Engineers is responsible for maintaining the breakwater and thus serves as the project manager. This project is research and development-oriented for demonstrating that habitat features can be incorporated into the design of blocks not only in Cleveland Harbor, but also in many other Great Lakes Harbors in the future. In fact, the grooved surface texture used in the project has been adopted for use on other toe blocks for repairing breakwaters by the Buffalo District because of its wave energy reducing properties. Monitoring the use of the blocks by aquatic species will be used to guide future block modifications at this and other harbors in the Great Lakes and elsewhere. The stakeholders identified in this win-win project are the Ohio Department of Natural Resources, the US Fish and Wildlife Service, and the US Geological Survey.Details
Deer Island Restoration/Beneficial Use of Dredge MaterialUSAThe Biloxi Harbor Navigation Project was federally authorized by the U.S. Congress in 1966. It provides a 12-ft deep navigation channel to support barge and vessel traffic into and out of commercial and industrial facilities, most notably a coal facility in Biloxi Harbor. Dredged material from this project was used beneficially at Deer Island to restore marsh, create habitat for terrestrial and aquatic species, and provide a more resilient shoreline for future storm events.The intent of the Deer Island Restoration/Beneficial Use of Dredge Material Project was to (1) restore Deer Island and (2) create long term disposal capacity for material dredged from the nearby Biloxi Harbor Navigation Project. Deer Island is a 3.5-mile long spindle-shaped island located adjacent to the navigation project and just off the coast of Biloxi, Mississippi. Though much of Deer Island endured through catastrophic storm events over the last century including Hurricanes Camille, Ivan, and Katrina, the storms destroyed forested areas, significantly eroded the sandy shoreline, and left elevations too low to support marsh vegetation. The Deer Island Restoration Project included the filling of a breach in the west end of the island, the restoration of the southern shoreline, and strategic vegetation plantings. Approximately 1.95 million cubic yards of hydraulically-dredged material from a nearby borrow site were utilized to fill the west end breach and restore the southern shoreline. Over 300,000 plants were planted on the island and, currently, another 325,000 plants are being planted. Importantly, the project included the construction of a 1 million cubic yard capacity lagoon specifically designed for the beneficial use placement of fine-grained dredged material from Federally-authorized navigation channels. Approximately 170,000 cubic yards of dredged material from the Biloxi Harbor Navigation Project were placed in the lagoon in October 2011. The principles and practices used for the Deer Island Restoration Project provide significant environmental benefits for the region, as well as protection for the City of Biloxi from storm events, recreation opportunities for people, and hard-to-come-by economically feasible and environmentally acceptable beneficial use opportunities for dredged material. Details