Stave River Water Use Plan - BC Hydro

Stave River Water Use Plan
Monitoring Terms of Reference June 13, 2005
benefits in littoral habitat. Because relevance of the ELZ measure was untested, the CC
expressed concern whether the perceived littoral benefit would actually be realised. As
a result, the CC also recommended that a monitor be designed and implemented to
measure changes in littoral zone development following implementation of the Combo 6
operating strategy.
1.2 Management Questions
The consultative committee identified four key management questions that must
be addressed pertaining to the littoral productivity of Stave and Hayward reservoirs.
These are:
a) What is the current level of littoral productivity in each reservoir, and how does it
vary seasonally and annually as a result of climatic, physical and biological
processes, including the effect of reservoir fluctuation?
This information is required to identify the key determinants that currently
govern/constrain the littoral productivity in each reservoir. Once these
environmental factors have been identified, an assessment can be carried out to
determine whether they are susceptible to change given alternative reservoir
management strategies. Environmental factors that are susceptible to change
are then monitored through time in conjunction with the productivity indicator
variable (in this case primary productivity). This information sets up the
foundation for the next management question.
b) If changes in littoral productivity are detected through time, can they be attributed
to changes in reservoir operations as stipulated in the WUP, or are they the
result of change to some other environmental factor?
This information allows one to determine whether there is a significant, causal
link between reservoir operations and reservoir littoral productivity, and if so,
describe its nature for use in future WUP processes, particularly in the context of
the ELZ performance measure. Implicit in this question is that gains or losses in
primary productivity reflect gains or losses in overall fish production.
c) A performance measure was created during the WUP process so as to predict
potential changes in littoral productivity based on a simple conceptual model.
The Effective Littoral Zone (ELZ) performance measure was used extensively in
the WUP decision making process, but its validity is unknown. Is the ELZ
performance measure accurate and precise, and if not, what other environmental
factors should be included (if any) to improve its reliability?
The ELZ performance measure is purely a conceptual construct at this stage.
Because decisions were made based on the values of this performance
measure, it is imperative that it be validated in terms of its accuracy, precision,
and reliability. Because littoral productivity is affected by reservoir operations
elsewhere in the province, the ELZ tool may prove useful in other WUPs. Its
transferability to other reservoirs should also be investigated.
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