More information on the Northwest Power and Conservation Council and Subbasin Planning throughout the Columbia Basin can be accessed from the Council’s web site.
Subbasin Planning
The Estuary Partnership led efforts to develop the Lower Columbia (River Mile 146-46) and Columbia Estuary Subbasin Plan. The two year project involved an assessment of all previous planning efforts within the two subbasins, a public outreach process, coordination with multiple dozens of stakeholders and a project oversight team, and writing the Subbasin Plans.
In 2002, the Northwest Power and Conservation Council (a four-state agency tasked with enhancing fish and wildlife and assuring the region an economic and reliable power supply) created the concept of subbasin plans. Subbasin plans were concieved of as a way to help the Council gather and refine scientific knowledge for each of the 62 subbasins within the Columbia River basin. The Council tasked local entities with developing the plans based on a Council established framework.
The Subbasin Plans include a description of the subbasins, an overview of focal species (those that have special legal, ecological, cultural, or local status and are used to evaluate the heath of the ecosystem and the effectiveness of management actions), and information on species habitat interactions and ecological relationships. The plans also include a technical assessment, and inventory of past and current efforts, and a management plan of objectives and strategies.
The Estuary Partnership also prepared a Subbasin Supplement. Similar to an Executive Summary, the Subbasin Supplement is a highly readable document that paints with a broad brush, prioritizing policies into five action oriented strategies and one supporting strategy that address fundamental issues and multiple species across the Lower Columbia and Columbia Estuary Subbasins. The five action-oriented strategies, and supporting strategy, in order of priority are:
Reduce the effects of the Columbia River hydrosystem
Flow changes over time have greatly impacted watershed wide processes such as hydrology, food webs and sediment budgets. These processes in turn have impacted species by creating new habitat types, altering freshwater and saltwater balances, changing food availability, and influencing migratory patterns. Implementing this strategy would involve adjusting Columbia River flows to simulate peak seasonal flow, increasing the variability of flows during certain periods, and restoring tidal complexity in the estuary. In addition, implementation would require maintaining adequate flows during spawning and migration periods, restoring connectivity between the river and the floodplain, and restoring sediment transport processes.
Protect and restore habitat
Over the last 130 years, human activities, such as urban and agricultural development, dams, diking and dredging, have significantly altered the lower Columbia River and estuary. From 1870 to 1983 for example, tidal swamp acreage declined by an estimated 77 percent and marsh habitat by 43 percent. Disconnected habitat, lack of habitat diversity, or lack of access to traditional habitats negatively impact species in a variety of ways. Implementing this strategy would require, among other things, protecting and restoring riparian and wetland habitat conditions and functions, restoring tidal swamp and marsh habitat, improving access to productive spawning and rearing habitat, and mitigating channel dredging activities. It would also require restoring connections between the river and its floodplain, sediment transport processes, and spring peak flows.
Address toxic contaminants
Agricultural practices and industrial and urban development in the lower Columbia River region have resulted in the accumulation of toxic contaminants such as DDT, DDE, polychlorinated byphenyls (PDBs), and metals, in sediments, fish tissue, and bald eagle eggs. Other contaminants of concern include dioxins, furans, various pesticides, and a variety of organochlorines and toxic metals which have been found at above guidance levels in fish tissue and sediment. Sublethal concentrations of contaminants affect the species survival by increasing stress – and susceptibility to disease, delaying normal growth patterns, and disrupting processes such as reproduction. Implementing this strategy would involve (1) extensive sampling to determine the locations and concentrations of contaminants and (2) reducing uncertainty about exposure risks to fish and wildlife. Once found, contaminant hot spots should be removed, treated, or contained by addressing contaminants at their source.
Slow introductions of non-native species
Over time, numerous fish, wildlife, and plant species have been introduced into the river’s ecosystem with deleterious consequences. Non-native species alter food web dynamics, transmit diseases and parasites, and compete for habitat with native species. They also often thrive by capitalizing on significantly altered systems such as the lower Columbia. The lower Columbia harbors more than 70 non-native species including 37 fish species such as walleye, American shad, and smallmouth bass, and plant species such as purple loosestrife, Eurasion water milfoil, and Brazilian elodea. Implementing this strategy would involve enacting regulatory, control, and education measures to prevent additional species invasions and establishing a moratorium on new intentional introductions. Stopping unintentional and uncontrolled introductions will require additional research and measures.
Reduce predation on focal species
Salmon, sturgeon eggs, lamprey, and Columbian white-tailed deer in the lower Columbia River are more likely to be killed by predators since ecosystem changes have dramatically altered many predator-prey interactions. Juvenile salmon are particularly susceptible to predation from Caspian Terns and northern pikeminnow – two species native to the region whose population numbers have increased dramatically over time. Although management actions have decreased their impacts, both terns and pikeminnow remain a key factor limiting juvenile salmon survival. Implementing this strategy would involve, among other things, further managing these and other predator species in the lower Columbia River.
Supporting Strategy: Manage Uncertainty
A huge hurdle in developing the subbasin plans and their strategies was the lack of documented understanding about how key species use the lower Columbia River and estuary over time, their habitat needs, and how watershed scale processes affect those habitats. Additional research is needed across the board to better understand the potential for restoration, the interaction of species and habitats, predator-prey interactions, and the impacts of introduced species and toxic contaminants. Implementing this strategy would involve testing and refining assumptions and hypotheses found in the subbasin plans, clarifying and resolving key questions still needing to be answered, and initiating needed research.
The Subbasin Supplement’s two-page conclusion acknowledges a number of complicating factors to implementation ranging from the interconnected nature of the strategies, to social, economic, or political constraints, to the need to actively monitor implementation in the event that projects have unintended results or reveal significant new information about species, habitats, or ecosystem processes.
Both the Subbasin Plans and the Subbasin Supplement set the stage for protection and restoration efforts to proceed in an informed manner. They build from many existing management plans and set the stage for more specific plans to recover threatened and endangered species. The Estuary Partnership, the Lower Columbia Fish Recovery Board, many local watershed entities, conservation organizations, local governments and others are already undertaking numerous habitat restoration and protection projects that implement Subbasin Plan and Supplement strategies.
The Subbasin Supplement as well as the complete Estuary Partnership Subbasin Plans for both the Lower Columbia River and Columbia Estuary can all be found in the Estuary Partnership Library.
