When the need became clear for massive upgrades to the levees that protect Sacramento, it triggered one of the largest and most complex environmental planning projects in California history. The extensive engineering work necessary to bring the levee system up to par carries with it the requirement of rigorous environmental permitting to make sure it is in compliance with the National Environmental Policy Act (NEPA), California Environmental Quality Act (CEQA) and other laws.

AECOM has led the five-year environmental compliance effort for Sacramento Area Flood Control Agency's (SAFCA) Natomas Levee Improvement Program (NLIP), which will provide the Sacramento metropolitan area with a 200-year level of protection.

The Natomas Basin floodplain in Sacramento and Sutter Counties comprises approximately 53,000 acres surrounded by more than 40 miles of levees. It is occupied by over 83,000 residents and contains approximately $8.2 billion in damageable property.

The area is designated for substantial development and provides habitat for several threatened and endangered species. Further development in Natomas Basin is on hold until appropriate flood protection is provided, which created an urgent need to accelerate the program. The presence of Sacramento International Airport in the basin further complicated the permitting process.

Since 2006, AECOM has been working closely with SAFCA, the U.S. Army Corps of Engineers (USACE), other consultants and a plethora of regulatory agencies to design, evaluate and implement the NLIP. Program features include: flood damage reduction components, aviation safety components, habitat conservation and management components and irrigation and drainage components.

The project will see roughly 10 million cubic yards of sediment moved with 1,600 acres of land affected. This work has included multiple, phased and overlapping environmental impact statements (EIS), environmental impact reports (EIR) and regulatory permitting, as well as ecological restoration, cultural resources conservation, public outreach and construction monitoring. More than 110 AECOM staff members have been involved.

Thousands if not tens of thousands of Native Americans once dwelled in the Natomas Basin. AECOM's team of 30 archaeological monitors discovered sites dating back as far as 7,000 years and artifacts such as obsidian projectile points, shell beads, bone awls, mortars and pestles and clay cooking balls. AECOM worked closely with USACE and tribal representatives to address these sites.

AECOM proactively attended engineering design meetings to identify and resolve environmental impact issues of the levee improvement works at an early stage, facilitating designs that addressed the Clean Water Act, as well as Federal Aviation Administration (FAA) regulations, access and acquisition constraints, ecological and cultural resources issues.

The Natomas Basin provides key habitat for the endangered giant garter snake and Swainson's hawk. It is covered under a habitat conservation plan and has several very active environmental groups. AECOM mobilized 25 wildlife biologists to address these concerns and facilitated two years of negotiation between resource and regulatory agencies and land managers. Ultimately, 1,450 acres of wildlife habitat were preserved or created.

AECOM's team of ecologists, biologists, landscape architects and regulatory specialists collaborated to produce and implement the mitigation and monitoring plans, programmatic long-term management plans and detailed construction plans and specifications. These documents met or exceeded agency standards and achieved regulatory approvals.

Jake Herson