Water Stewardship Information Sources

Citation Hatfield, T, Lewis, A, Ohlson, D and Bradford, M. 2003. Instream flow thresholds as guidelines for reviewing proposed water uses - Synopsis. Prepared for BC Ministry of Environment.
Organization Ministry of Environment
URL http://www.geoscientific.com/technical/tech_references_pdf_files/BC%20Instream%20Flow%20Guidelines%20for%20Fish.pdf
Abstract/Description or Keywords British Columbia has abundant water resources, which sustain productive aquatic ecosystems
and many uses by humans (e.g., fishing, power generation, irrigation, drinking water, industrial
uses, recreation, etc.). Determining how much water can be extracted from a river without
negatively affecting fish and fish habitat is a daunting task, but one that is frequently asked of
resource managers. The Ministry of Water, Land and Air Protection (MWLAP), Ministry of
Sustainable Resource Management (MSRM), Land and Water BC Inc. (LWBC), and Fisheries
and Oceans Canada (DFO) are developing the British Columbia Instream Flow Guidelines for
Fish (referred to here as “the Guidelines”) to aid in the process of setting instream flows in
British Columbia streams. These Guidelines deal specifically with instream flow requirements
to support aquatic ecosystem values. They do not address other environmental protection
issues related to conserving fish, wildlife or plant communities (e.g., “footprint” impacts,
construction impacts, or cumulative effects).
The Guidelines are made up of two main components, Flow Thresholds, and Assessment
Methods. The Guidelines support a two-tiered review process for proposed water uses on BC
streams (Figure 1). The first tier is a scoping level process that provides thresholds for
alterations to natural stream flows that are expected to result in low risk to fish, fish habitat, and
productive capacity. These thresholds are meant to act as a “coarse filter” during the review of
proposed water uses on BC streams when there is little or no biological or physical data
available. Projects that propose to exceed these flow thresholds must collect additional data,
which will be reviewed and used during a more detailed project review (the second tier). The
Assessment Methods are a set of endorsed techniques for assessing flow alterations on British
Columbia streams. The Assessment Methods concentrate on techniques for collecting data used
during more intensive project reviews.
This document presents a synopsis of the instream flow thresholds proposed as part of the
Review Guidelines. A more detailed analysis (project description and history, literature
reviews, data analysis, and performance assessment) is presented in Hatfield et al. (2003). The
Assessment Methods are presented in a separate document (Lewis et al. 2003). low flow, environmental flow needs, EFN, aquatic habitat, fisheries, salmonids
Information Type report
Regional Watershed Province
Sub-watershed if known
Aquifer #
Comments
Project status complete
Contact Name
Contact Email