How well do we know our watershed?

What do we know about our watershed and are there gaps in the information being collected?

By Dr. Peter Sale.

The Muskoka River Watershed stretches over 5,400 square kilometres of forests, farmlands, towns, wetlands, streams, rivers and lakes from Algonquin Park to Georgian Bay. Some of us have explored large parts of it, but most of us know only certain special places — places where we live, work and play.

But I did not mean that kind of knowing. I meant how well do we know the detailed characteristics of our watershed, water flows, lake water quality, forest health, resident species, and so on? And how our watershed is changing? If we do not know our watershed very well, we will have a difficult time caring for it.

Compared to much of Ontario, this watershed is quite well known, because provincial ministries, municipalities, Indigenous communities, lake associations and myriad others have been collecting information about the watershed for many years. But how well is quite well? And do we know it well enough to be able to manage it effectively? Particularly at a time when it is being buffeted by climate change, and subjected to growing development pressure?

In 2022-23, the Ontario Ministry of the Environment, Conservation and Parks provided $5 million to improve our knowledge. Sixteen projects, recommended by Muskoka Watershed Advisory Group, were completed by the District of Muskoka (12 projects), Town of Bracebridge, Westwind Forest Stewardship Inc., Friends of the Muskoka Watershed and Muskoka Watershed Council (one project each). These projects varied in size and scope and final reports are available.

Integrated watershed management (IWM) requires baseline information that characterizes the watershed in sufficient detail to permit detecting small changes in watershed status through time. This is done by comparing baseline and newly acquired data. Managers also can ask ‘what if’ questions about anticipated changes before the changes occur. Such modelling could lead to improvements to a development plan or provide early warning of climate effects so action to lessen impact and better sustain the watershed ecosystem can be taken.

So, the 16 projects have expanded our knowledge, but do we now have all the information we will need for IWM? Or have we simply scratched the surface of an enormous amount we need to know but do not yet know? Are there gaps in what we know? Unknown unknowns that will rise up to bite us in the future? We need to find out what data has been collected, by whom, in what parts of the watershed and when. We also need to know the methods used and any modelling done. Is the data comparable from one part of the watershed to another? And we need to know what ongoing monitoring is in place.

Doing this is one of the first steps on the path toward implementing IWM. The fancy term is a synthesis and gap analysis of existing data. Which means sifting through all the records on all those websites, compiling a detailed inventory, evaluating methods used, frequency of monitoring and where the gaps are. These gaps may be geographic because some parts of the watershed are pretty remote, or they may be gaps due to a failure to recognize and collect needed information. Once that synthesis and gap analysis is completed, it will be possible to determine environmental monitoring needs for the future, and put in place procedures for sharing, evaluating, and using the collected data in management decisions. Maximally useful data and cost savings are likely outcomes.

MWC is working with municipalities and Indigenous communities to move toward IWM. As one step in this multi-year process, MWC will be leading a synthesis and gap analysis later during 2025, with completion in 2026. Stay tuned.

This is article #16 in First Steps on the Path to IWM, the current series of articles from the Muskoka Watershed Council. Author of this article, and series editor, is Dr. Peter Sale, retired aquatic ecologist, Muskoka resident and director of MWC. This article was published on MuskokaRegion.com on March 22, 2025.