Chapter 2 – Integrated Watershed Monitoring Program
Release Date: October 2012
Chapter 1 asked the key question that will be addressed throughout the Credit River Watershed Health Report: How healthy is the Credit River Watershed?
To answer this question, CVC’s expert staff are continuously monitoring different components of the environment through the Integrated Watershed Monitoring Program (IWMP). This program began in 1999. It provides a wealth of scientific information that supports CVC’s Vision of “An environmentally healthy Credit River Watershed for present and future generations” (CVC 2008).
Since the start of the IWMP, CVC staff has collected data from 289 unique stations throughout the watershed.
Each component of the IWMP utilizes a standard set of protocols. These protocols have all gone through rigorous peer review and many were developed by federal or provincial agencies. Protocols can include information on all stages of a monitoring program:
- data collection;
- data entry & storage;
- data analysis; and
Highly trained staff are used at all stages of monitoring. Data are subjected to a thorough quality control process prior to analysis to ensure scientifically-credible results.
Every five to ten years, CVC conducts an intense review where experts from outside CVC are involved in examining all stages of the IWMP. This review also includes a statistical analysis of status and trends in each of the monitoring components. The following chapters will be presenting the most up-to-date statistical results of the IWMP.
IWMP: Key Piece of the Feedback Loop
A well-designed monitoring program includes a section that communicates results back to decision-makers. This ensures that management of the watershed’s environmental resources is occurring with the most up-to-date information. In the case of the Credit River Watershed, the scientifically robust information provided by the IWMP provides the necessary information to adjust future management of the watershed based on sound science and expertise.
Adaptive Environmental Management (AEM) is based on a learning process that informs decision making with the goal of reducing uncertainty over time (Holling 1978). Monitoring provides the scientific information necessary for the AEM process to deliver improved management actions and outcomes in both the short and long term. The IWMP uses the principles of AEM itself and is a key component in the AEM process (Figure 1).
AEM recognizes that ecosystems are dynamic and that using the most up-to-date information available requires management to be flexible. If the environment is showing signs of decline, then CVC and all other stakeholders must respond accordingly through appropriate management actions. Monitoring would continue to see if the adjusted management actions are reflected in the environmental status and trends.
Figure 1: Adaptive Environmental Management
Ecological monitoring programs are commonly designed based on a conceptual framework. This framework enables understanding of the ecological integrity, or health, of an ecosystem. Ecological integrity is defined as:
“the condition of ecosystems in which,
a) the structure, composition and function of the ecosystems are unimpaired by stresses from human activity,
b) natural ecological processes are intact and self-sustaining, and
c) the ecosystems evolve naturally.”
A conceptual framework is important for setting clear definitions of key features of the ecosystem including stressors, components, indicators and parameters. This type of framework is also used for:
- reducing complexity of ecosystems;
- identifying relationships of ecosystem features; and
- identifying gaps in a monitoring program.
(Parks Canada 2007)
A conceptual framework is critical for ensuring key questions can be answered, such as ‘How healthy is the Credit River Watershed?’. The IWMP answers this question by monitoring ecological health and integrity of the watershed ecosystem. The conceptual framework can then guide practitioners in determining what sort of data (parameters) to collect.
Figure 2: IWMP Conceptual Framework
Two major stressors in the Credit River Watershed are land use change and climate change. These will be the focus of upcoming chapters. Other stressors in the watershed include: harvesting of biological resources and increase of invasive species.
The Credit River Watershed Health Report presents, by chapter, components of the IWMP – climate, streamflow, groundwater, fluvial geomorphology, terrestrial ecology, surface water quality, benthic macroinvertebrates and fish. Each chapter will examine the status and trends for a set of indicators established for each component.
The IWMP components and definitions are presented in Table 1.
Table 1: IWMP components and definitions
A variety of indicators of watershed health are measured through the IWMP. Each component may have several indicators that together represent ecosystem structure, composition and function. Together these indicators provide a comprehensive view of ecological integrity or health of the Credit River Watershed. When any of these indicators reaches a defined threshold, it signals a trend of concern requiring further investigation.
The signal for each indicator varies over area and time. Some responses are immediate while others occur over a broader area or longer period of time. For example, flowering plants can respond rapidly within a season to changes in soil moisture and rainfall frequency, whereas trees may take longer to respond. Component chapters will discuss the indicators used.
IWMP indicators may be comprised of several parameters, each of which helps to summarize the status or trend in that indicator. Component chapters will discuss the parameters used.
Physiographic Zones of the Credit River Watershed
CVC monitors each of the above components of the Credit River Watershed across the watershed’s three major physiographic zones (Figure 3) described below.
Figure 3: Physiographic zones of the Credit River Watershed
The Upper Watershed lies above the Niagara Escarpment and includes all areas north of Inglewood. This zone is comprised of till plains, moraines and glacial spillways. Generally, soils in the Upper Watershed are highly permeable, allowing a significant amount of infiltration that supplies the regional groundwater system. Agriculture traditionally dominates land use in this zone. The amount of cultivated land has decreased in recent years, being replaced by small hobby farms. Settlement areas in the Upper Watershed include Orangeville, Erin, Alton, Caledon Village, and Hillsburgh.
The Middle Watershed contains the Niagara Escarpment and the western edge of the Oak Ridges Moraine. This zone is characterized by steep slopes, significant rock outcrops and thin overburden soil conditions. Extensive natural areas and numerous protected areas exist in this portion of the watershed. The topography in this zone leads to relatively high runoff volumes and velocities, though the forest cover tends to slow runoff and increase infiltration. Settlement areas in the Middle Watershed include Inglewood, Cheltenham, Terra Cotta, Ballinafad, Acton, Georgetown and Norval.
The Lower Watershed consists of the Peel Clay Plain and the sandier Lake Iroquois Plain. Soils in the Lower Watershed have low permeability compared with other areas of the watershed, resulting in higher runoff. Topography in the area is generally flat with a gentle southward slope towards Lake Ontario. This zone is highly urbanized and is home to 87% of the watershed’s population. Natural cover is low, with few remaining forests and wetlands. The Lower Watershed includes most of the City of Mississauga, the western half of the City of Brampton and the eastern portion of the Town of Oakville.
The next chapter of the Credit River Watershed Health Report takes a closer look at different land uses across the watershed and how these are changing. It also explores the effect of growth and urbanization on the health of the watershed.
CVC (Credit Valley Conservation). 2008. Strategic Plan Update 2008.
George Morris Centre. 2009. Demographic Profile of the Credit River Watershed.
Holling, C.S. 1978. Adaptive Environmental Assessment and Management.
OMMAH (Ontario Ministry of Municipal Affairs and Housing). 2002. Oak Ridges Moraine Conservation Plan. Queen’s Printer for Ontario.
Parks Canada. 2007. Monitoring and Reporting Ecological Integrity in Canada’s National Parks, Volume 2: A Park-Level Guide to Establishing EI Monitoring, March 2007.
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