Page 503 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

Chapter 15 River Systems 467
▲Figure 15.1.2 excavator removing the concrete dam ▲Figure 15.1.3 Coursier Dam in British Columbia after notch on Marden Creek near Guelph, Ontario, in 2010. cut to drain reservoir. [BC Hydro.]
[Emily giles/WWF Canada.]
may be linked to processes occurring up- stream and in turn can affect downstream processes. Thus, restoring a stream to its natural state involves the entire system rather than just a single, isolated seg- ment. Restoration also involves balancing different water use needs within a drain- age basin.
Parks Canada has partnered with
the Central Westcoast Forest Society and more than 20 other government agencies, First nations, environmental groups, and businesses to restore the Kennedy Flats Watershed since 1994, with efforts ongoing. This area is lo- cated on the west coast of Vancouver Island, with a portion lying within Pacific Rim national Park Reserve. As of 2009, the project has included 66 hectares of riparian habitat and 78 km of in-stream restoration, and over 10 hectares of landslide stabilization and 114 km of logging road deactivation. For a de- scription of this project see www.pc.gc .ca/eng/progs/np-pn/re-er/ec-cs/ec-cs06 .aspx.
In 2007, restoration specialists par- tially breached the Sawmill Dam on the Acushnet River in Massachusetts and con- structed a passage structure, or “fishway,” consisting of a stone step-pool system designed to mimic natural conditions (Figure 15.1.4). Data collected from 2007 to 2011 show that river herring (alewives and blueback herring) increased over 1000%
as fish passage around Sawmill and an- other nearby dam allowed access to prime spawning grounds.
Stream Restoration Science
Stream restoration practices have become a lucrative business for hun- dreds of companies throughout north America. However, the science of stream restoration is still in its infancy. Research conducted at the Canadian Rivers Insti- tute at the University of new Brunswick (canadianriversinstitute.com) and the BCIT Rivers Institute (commons.bcit.ca/ riversinstitute/), and other academic institutions and government agencies in Canada contributes to in-
that are necessary to advance and improve stream restoration science is the Baltimore Ecosystem Study by the Long Term Ecological Research network (www.lternet.edu/sites/bes).
Ongoing dam removals and contin- ued societal and scientific emphasis on ecosystem health have made stream restoration science a growing field of applied fluvial geomorphology, and one to which geographers and other Earth systems scientists are poised to contribute.
creasing our understand- ing of river environments and stream restoration practices.
At the multidisciplinary national Center for Earth Surface Dynamics at the University of Minnesota, one research goal is to de- velop a set of free, down- loadable scientifically based tools that promote quantitative restoration methods (see www.nced .umn.edu/content/streams- science-restoration/). One example of the long-
term ecological studies
▲Figure 15.1.4 Step-pool fishway construction on the Acushnet River, Massachusetts. [nOAA.]