The purpose of the Potomac Flow-by Study was to investigate and develop
a method or methods to evaluate the environmental flow-by requirements
of the mainstem Potomac River between Seneca Creek and Chain Bridge.
Summary of Issues that led to the
2001-2004 Potomac Low-Flow Studies
Next Steps for Potomac flow-by Evaluation (as of December 2005):
- Supplement physical habitat measurements during the next low-flow
period (< ~1400 cfs); measurements made below Little Falls Dam in
October 2005 (completed;
addendum to Habitat report updated on web page)
- Develop a list of fish and mussel species and low-flow habitat preferences
as possible indicator species (draft list attached to meeting
minutes of September 2005 workshop)
- Develop a conceptual model of the ecological relationship between
species and their habitat (draft
conceptual model by Jules Loos available here)
- Develop research plans, estimated costs, further refine indicator
species for study
- Ultimate goal: evaluate the adequacy of the current flow-by numbers
and set new flow-by as needed, considering duration and frequency
of minimum flows.
See the Middle
Potomac River Watershed Assessment for more recent efforts "to
quantify Potomac watershed environmentally sustainable flows -- flows
that sustain healthy river ecosystems and the goods and services that
humans derive from them"
See also the ICPRB publication titled Potomac
Basin Large River Environmental Flow Needs published May 2011.