Shell Pipeline Company LPBlue Hammock Bayou Crossing

Blue Hammock Bayou Crossing Natural Infrastructure Pilot Project

Site Features

Channel Width680 feet

Pipeline Size16 and 22 inches

Soil ConditionsSoft to very soft clay, with organics, silt and sand seams, and shell fragments

ContactsDonnie Garrison Shell Pipeline Company LP

Amanda Gaze CH2M

Heather Layrisson CH2M

A solution that improves through time

Maintaining a pipeline in Louisiana’s coastal zone is no easy task. Erosion by tides and storms threaten to expose and undermine pipelines, and companies throughout the Gulf frequently repair and rebuild structures as they degrade due to environmental factors, ultimately increasing the cost of production and the price of energy. This ongoing expense, coupled with the state’s priority to better preserve its land base and the ecology of coastal zones, meant that a fresh, longer-lasting approach needed to be found.

The Blue Hammock Bayou is the first natural infrastructure pilot project to be completed by Shell Pipeline Company LP. This innovative solution to long-standing coastal zone challenges succeeded beyond expectations. Not only has erosion around the valuable pipeline assets been halted, the process has actually been reversed as the sediment deposition and vegetation growth rates are faster and higher than anticipated. Because of this, Shell Pipeline Company LP expects fewer operations and maintenance issues, which helps reduce costs. The State of Louisiana benefits from restoration of coastal lands as a buffer against future storms, as well as improved marsh and aquatic habitat. The project is on a trajectory to improve over time and this approach can be replicated within the coastal zone.

What is the challenge?Localized erosion occurring at the intersection of canals with natural bayous is a challenge in coastal Louisiana. Erosion from the hydrologic processes in the tides and canals create a continuing pipeline maintenance cycle that impacts the industry tremendously, increasing costs and contributing to potential integrity issues. Past infrastructure solutions, using concrete and other conventional construction materials, deteriorate over time and do little to enhance the existing ecosystem.

www.ch2m.com Follow us @ch2m

© 2017 CH2M HILL

Working with nature through natural solutions often has better outcomes

About CH2M

CH2M leads the professional services industry delivering sustainable solutions benefiting societal, environmental and economic outcomes with the development of infrastructure and industry. In this way, CH2Mers make a positive difference providing consulting, design, engineering and management services for clients needing world-class solutions in environmental; industrial and advanced facilities; transportation; and water markets, from iconic infrastructure to global programs like the Olympic Games.

Ranked among the World’s Most Ethical Companies and top firms in environmental consulting and program management, CH2M in 2016 became the first professional services firm honored with the World Environment Center Gold Medal Award for efforts advancing sustainable development.

Why natural infrastructure?During the past decade, people have become much more aware of the inherent value of coastal wetlands and habitats in the Gulf of Mexico. Beyond the ecological value of the habitat, coastal wetlands protect oil and gas infrastructure and associated facilities, which are critical to the local economy.

Natural infrastructure can adapt more readily to the surroundings and improve over time, while enhancing the local ecosystem.

Benefits of natural infrastructure solutions include:• Increased pipeline integrity by maintaining

overlying protective sediments

• Reduced cost for continued pipelines maintenance

• Improved marsh production and water quality, flood risk reduction, and aquatic resource benefits

How did you do it?Both the northern and southern shorelines had to be addressed, as well as the mudflats, to have a successful outcome. The design features of the north shoreline site included installing several rows of HESCO erosion control baskets filled with sediment and vegetation. The design features for the southern shoreline included installing coir logs filled with rock and coconut

fibers protected with coir mattresses along the shoreline in front of the logs; filling and compacting sediment behind the existing riprap berm; and placing vegetation in new fill area. Throughout the project, the planting selection was geared toward robust clonal species with adaptation to depth and energy.

Construction of the Blue Hammock Bayou Pilot Project, completed in 2015, was carefully conducted to minimize disruption to the existing marsh. The contractor focused on methods to reduce health, safety, and environmental exposures and ensured that there was no potential for exposure or damage to the Ship Shoal pipeline.

What’s next?Monitoring data, from site visits throughout 2016 and 2017, indicate that the natural infrastructure approach is already performing beyond expectations, with robust plant growth and accumulation— rather than erosion—of sediments. This pilot project is the first of many natural infrastructure solutions that are planned along the Ship Shoal corridor. Shell intends to use these solutions to help stabilize the shorelines at the bayou crossings, improve vegetation and sediment deposition, and reduce future maintenance costs while enhancing the local ecosystem.