Watershed management provides for a rational and scientific approach to natural systems conservation, restoration and use. The information collected from years of monitoring coupled with community knowledge is used as the basis of watershed and fisheries management planning. These plans provide recommended actions that will guide watershed management for current and future generations.
Watershed management actions include tools and programs related to protecting people and property (flood forecasting and warning), improving watershed health and monitoring overall watershed conditions in terms of the following topics: groundwater quantity and quality, surface water quantity and quality, aquatic resources and terrestrial resources.
GRCA Watershed Monitoring Plan - 2014
|Flood Forecasting and Warning|
The Ganaraska Region Conservation Authority
maintains a flood forecasting and warning system. The purpose of the
system is to reduce risk to life and damage to property by providing
local agencies and the public with advanced notice, information and
advice so that they can respond to potential flooding and flood
A flood is defined as a situation where water levels in a
watercourse exceed the channel banks. Flooding in Ontario is a fairly
common occurrence. The greatest flood in recent memory hit the Port Hope
area in March of 1980 when the Ganaraska River flowed over its banks as
a result of heavy rainfall on a dense snow pack. Rain on snow is not
the only type of event that can cause flooding. Hurricanes moving north
from the tropics can carry heavy rainfall into Ontario commonly
resulting in flooding, particularly in larger watersheds. High local
rainfall associated with severe thunderstorms can cause flooding usually
associated with smaller watersheds. Winter ice jams associated with
spring break up have also resulted in severe flooding situations. High water levels and/or storm surges on Lake Ontario can also result in flooding along the lakeshore.
The Ganaraska Region Conservation Authority operates its daily
planning cycle to monitor, on an ongoing basis, weather forecasts, radar
and watershed conditions at locations across the watershed. Water level
and related information is remotely collected through an extensive
network of stream gauges, rain gauges, snow course sites and staff
gauges (monitoring network). Our extensive knowledge and historic data
on the watershed's responses to extreme weather and conditions in our
watersheds is used to develop a flood forecast.
When conditions warrant, GRCA will communicate with local agencies (municipalities, emergency services, local media, school boards and government agencies) issuing flood messages following a standard format used by all Conservation Authorities. During spring snowmelt or severe storms, the
Conservation Authority estimates the severity, location, and timing of
possible flooding, and provides these forecasts to local agencies using one of the following message formats:
Watershed Conditions Statement - Water Safety - High
flows, unsafe banks, melting ice or other factors that could be dangerous for
recreational users such as anglers, canoeists, hikers, children, pets, etc.
Flooding is not expected.
Watershed Conditions Statement - Flood
Outlook - Early
notice of the potential for flooding based on weather forecasts calling for
heavy rain, snow melt, high wind or other conditions that could lead to high
runoff, cause ice jams, lakeshore flooding or erosion.
Flood Watch – Flooding is possible
in specific watercourses or municipalities. Municipalities, emergency services
and individual landowners in flood-prone areas should prepare.
Flood Warning – Flooding is
imminent or already occurring in specific watercourses or municipalities.
A flood event may be defined as a sudden increase in watercourse
levels resulting from the occurrence of precipitation, snowmelt, or a
combination of the two. The severity of flood events can range from
minor increases in creek levels (resulting in “hazardous creek
conditions”), to extreme flood conditions (posing a risk to life and
property). These various types of events, and the corresponding flood
response activities, are described in the Ganaraska Region Conservation
Authority’s Flood Contingency Plan.
To find out if a flood message has been issued please consult the following:
Radio, television and daily media will air flood messages
Go to the GRCA website at www.grca.on.ca
Call the GRCA directly at 905-885-8173
Contact your local municipality
If you have an urgent flooding concern, please contact your local
municipality. In case of a flood emergency, please contact our
Flood Duty Officer at 289-251-2094 or 289-251-1010.
FLOOD FORECASTING & MONITORING STATIONS
|STATION NAME|| ||MEASURED PARAMETERS|
|Wilmot Creek (3rd Concession, Clarington)|| ||Water Level, Rainfall|
|Wilmot Creek (7th Concession, Clarington)|| ||Water Level, Water and Air Temperature|
|Graham Creek (Newcastle)|| ||Water Level and Water Temperature|
|Ganaraska River (Sylvan Glen)|| ||Water Level|
|Ganaraska River (Osaca)|| ||Water Level|
|Northwest Ganaraska River (Osaca)|| ||Water Level, Water and Air Temperature|
|Cobourg Creek (Cobourg)|| ||Water Level, Rainfall, Water and Air Temperature|
|Cobourg Creek West Branch (Telephone Rd.)|| ||Water Level, Water and Air Temperature|
|Baltimore Creek (Baltimore)|| ||Water Level, Rainfall, Wind Speed and Direction, Water and Air Temperature|
|Ganaraska Forest Centre|| ||Rainfall, Snowfall, Wind Speed and Direction, Air Temperature|
|GRCA Main Office|| ||Rainfall, Relative Humidity, Wind Speed and Direction, Air Temperature|
| Groundwater Monitoring|
The Ganaraska Region Conservation Authority
(GRCA) has developed and currently implements a comprehensive
groundwater program. The program consists of several projects and
initiatives aimed at enhancing the understanding, protection, and
management of groundwater resources within the authority’s watersheds. These projects include groundwater monitoring, modeling, surface water
and groundwater interaction, as well as data collection and technical support
activities. Data collected and analyzed through the groundwater programs
is used in local planning initiatives including drinking water source
protection, watershed plans and fisheries management plans.
As part of the GRCA watershed wide integrated monitoring program, the
main objective of the groundwater monitoring project is to quantify
groundwater level fluctuations, groundwater flow directions and
gradients, monitor groundwater quality at selected locations, and record
changes over time. The groundwater monitoring project includes the
Provincial Groundwater Monitoring Network (PGMN) Wells
A number of recent studies conducted in Ontario have suggested that
groundwater resources are under increasing stress from factors that
affect both water quality and quantity. Long-term integrated groundwater
monitoring programs are needed to address these issues. In 2001, the
Ontario’s Ministry of the Environment (MOE) initiated the
development of a Provincial Groundwater Monitoring Network (PGMN) in
partnership with conservation authorities and a number of municipalities
across the province. The PGMN program focuses on monitoring of water
level and water quality in selected and instrumented monitoring wells
within each conservation authority. Data generated from this network provides supporting background information for groundwater resource
management areas such as drought response, scientific modeling, water
policy development, and land use planning.
The GRCA has been
actively involved with the PGMN program since September 2001. PGMN
monitoring wells were selected to monitor ambient conditions in shallow
and deep aquifer systems. To date, 17 wells across the GRCA watersheds
have been incorporated into the network, 15 of which are instrumented
with automated water level monitoring and telemetry equipment, and 2
with manual download stations. Dedicated water quality sampling pumps
were installed in 11 wells. Five annual rounds of groundwater samples
were also collected from the majority of the wells and analyzed for
water quality parameters. The PGMN wells provide necessary
baseline data and aid the GRCA in making informed land use planning and
sustainable groundwater management strategies.
Base Flow Monitoring
The groundwater system supports aquatic species and their habitats by
providing baseflow to the rivers and creeks. Baseflow is defined as
that portion of the total flow within a stream section that is derived
exclusively from groundwater discharge. Following a period of little or
no precipitation, essentially all flow within a river system can be
baseflow, notwithstanding possible anthropogenic inputs (e.g. such as
the release of water from various sources of surface storage, ponds, and
storm water sewers). Baseflow contributes to habitat conditions that
support a healthy aquatic ecosystem. Changes to the quantity and
quality of groundwater discharge can affect the aquatic ecosystem.
Monitoring of low flow in local streams is particularly important for
the management of water resources since demand for water usually
increases during dry weather. As a result, streamflow may approach the
minimum requirements to sustain ecological or water quality functions. Groundwater discharge is often concentrated in particular areas as a
result of changes in topography, geology, and the nature of the
groundwater flow regime.
GRCA technical staff and students
monitor baseflow during summer seasons when precipitation is expected to
be low. Suitable sites selected for the spotflow monitoring are
intended to be generally representative of entire watershed or smaller
catchments in a subwatershed.
To assess surface water and groundwater interactions within the GRCA
watersheds, a streambed monitoring and data collection
program was initiated during the 2005 monitoring season. This
program focused on monitoring surface water and groundwater vertical
hydraulic gradients using streambed piezometers installed in selected
locations of high water table elevation and potential groundwater
discharge. Several steps have been taken by GRCA staff to select proper
locations for piezometers installation and monitoring. These
included review of surficial geology maps, temperature monitoring data,
fish communities’ distribution, and thermography survey maps.
collected from 16 streambed piezometers as well as analysis of climate
data, baseflow data, fish communities, and temperature data allow
GRCA staff to quantify surface water and groundwater interaction.
|Low Water Response|
Fresh water is a natural resource crucial to
the economic and environmental well being of Ontario. Water supports
almost all aspects of human activity including health, industrial
development, and recreation. Because water is critical to so much of our
activity, it is managed from several perspectives and by many
jurisdictions, groups and individuals.
The Ontario Low Water
Response program is intended to ensure provincial preparedness, to
assist in coordination and to support local response in the event of a
The GRCA monitors precipitation and stream flows
throughout the year using the hydrometric network to make comparisons
with historic data in support of the Ontario Low Water Response Program. This comparison allows the GRCA to clearly identify when local watersheds enter drought conditions.
The GRCA administers the Ganaraska Low Water Response Team, which
has been created to coordinate the activities of water management
agencies with respect to dissemination of information, analysis, and
response to water events including drought.
August 2016: Drought conditions are affecting much of Southern Ontario this
summer including the Ganaraska Region where
only 45% of the normal rainfall has fallen since April 1st. With the lack of
rainfall, farmers and homeowners need to use water to sustain crops and
gardens. However, over-consumption of this precious resource can lead to more
severe impacts should the dry conditions continue. Reduced crop yields and
suffering vegetable gardens are just some of the possible impacts. With greater
demand from surface water and groundwater sources, water levels are declining
below normal. As this happens, organisms that live in the streams experience
warmer temperatures, reduced flow and habitat area, and increased
concentrations of nutrients and contamination are possible. Shallow groundwater
wells can become dry or fail to supply enough water to homes and businesses. This
is the time to review how we use water and what conservation practises we can
implement to reduce demand for water. This short term initiative will help to
conserve our water resources and reduce the overall impact to the ecosystem
until more consistent rainfall returns.
Follow these guidelines to conserve and use water wisely:
Leave lawns to go dormant, they will recover in the late summer as the sun's intensity diminishes
Use drought tolerant plants in gardens as much as possible
When watering gardens, soak the soil deeply to increase soil moisture and promote deep root growth
Water up to 1" or 25mm per week including rainfall
Try to avoid watering during the day when evaporation is highest, early morning or at night is the best time
Water on alternate days and use alternate sources (wherever possible) to spread out the impact of water takings
Make use of water storage (e.g. rain barrels, cisterns, off-line ponds)
Observe water conservation by-laws and encourage neighbors to comply
|Groundwater Indicator for Low Water Response Program|
The Ontario Low Water Response (OLWR) program relies on precipitation and stream flow indicators to evaluate low water conditions in watersheds across the province. These indicators provide water managers with objective information on the severity of low water conditions that may require a response to reduce water demand. Low water conditions are characterized as one of three levels of increasing intensity: Level I (Conservation), Level II (Conservation, Restriction) and Level III (Conservation, Restriction, and Regulation).
The OLWR program has identified the need for a groundwater indicator to be added to the program and used in conjunction with the rainfall and stream flow indicators.
7 PGMN wells have been selected and tested for their suitability to the OLWR program.
|YPDT- CAMC Groundwater Management Study and Modeling|
The Oak Ridges Moraine (ORM) is an extensive stratified sediment complex (60 km long and 5 to 20 km wide) stretching across southern Ontario from the vicinity of Trent River in the east to the Niagara Escarpment in the west. It is recognized as a regional groundwater recharge area, providing a source of groundwater to numerous aquifers and to the streams having headwaters on the flanks of the moraine including the Ganaraska River, Wilmot Creek, and Cobourg Creek watersheds within the GRCA. The York, Peel, Durham, Toronto – Conservation Authorities Moraine Coalition (YPDT – CAMC) Group was formed through the recognition of the natural, social, and economic importance of this feature.
The YPDT –CAMC Groundwater Management Study is being conducted to provide a hydrogeological analysis suitable for water resources management encompassing the watersheds emanating from the ORM. The project reflects the interests of four municipalities and nine conservation authorities that are working together to better understand groundwater issues across the ORM area. It is the goal of the partnered agencies that the project is maintained as a long term initiative in order to continually build on the early development, encompass new data, and foster constructive improvements to the existing work. The five key strategic components of the YPDT – CAMC are:
1. Policy framework development.
2. Data collection and management.
3. Technical analysis/studies.
4. Implementation framework.
5. Monitoring and evaluation.
As part of the YPDT – CAMC work, a regional-scale three dimensional geologic model and several MODFLOW groundwater flow models have been developed that span the entire Oak Ridges Moraine (ORM) and the surrounding area. The primary objective of these modeling efforts is to develop tools to help understand the geology and hydrogeology of the ORM and to support the many land use decisions being made in the area. The most extensive of these models is the regional MODFLOW model which was built on a SiteFX / ViewLog platform. The regional model is based on 5 hydrostratigraphic layers with a nominal cell size of 240 by 240 meters and covers an area encompassing all watersheds that originate on the Oak Ridges Moraine including the GRCA 5 major and 4 groups of watersheds. The model layers represent the major aquifer and aquitard units in the overburden and upper bedrock formations.
The YPDT – CAMC program continues to update the geological and hydrogeological understanding of the region and subsequently to refine the groundwater flow models. The GRCA staff work with the YPDT – CAMC team to refine and build on the existing understanding of the geological layers and groundwater flow system within the GRCA watersheds. The YPDT-CAMC geology and groundwater work currently in progress and includes the following tasks:
1. Maintaining and enhancing the database (e.g. adding new high quality wells, conversion from Access to SQL... etc).
2. Refining the geological layers based on new drilling information that is being collected by the partners from various projects.
3. Ensuring more effective access by partner agencies to the database.
4. Assisting with the application of numerical groundwater flow models to local site problems and investigations.
5. Liaising with the consulting community to ensure broader utilization of the program's data, interpretive geological layers, and modeling files.
The updated and verified database, hydrostratigraphic model layers (geologic model), and groundwater flow model represents significant technical products for the GRCA groundwater program. These products, together with surface water modeling, are used as the technical foundations in many areas including management and protection of water resources, watershed planning studies, other studies and initiatives.
|Water Quality Monitoring|
The GRCA operates a number of surface water
quality monitoring programs designed to understand the water quality of our watersheds, determination of trends in water quality, and provide long term monitoring of
watershed health. The data collected from these programs is analyzed
and used in watershed management through planning, fisheries management
planning, source water protection planning and water quality reporting.
Ministry of the Environment (MOE) operates the Provincial Water Quality
Monitoring Network (PWQMN). Conservation Authorities such as the GRCA and
other agencies are partners in the PWQMN by collecting samples and
sending them to the MOE lab.
The GRCA has completed sampling
throughout its jurisdiction to characterize surface water quality for
all of its watersheds. Current programs are focusing on characterizing
water quality during low flow periods when watershed health is
experiencing the most stress and during high flows when the water
quality is typically degraded.
Typical parameters that are
measured in these water quality programs include temperature, pH,
conductivity, turbidity, suspended solids, major ions, nutrients, metals
Water Quality Monitoring
Wetlands provide environmental functions that are important to both
humans and wildlife. These functions may vary among wetlands depending
on the size of the wetland, its soils, plant community, and position in
the landscape. For example, wetlands found in upper watersheds are very
important as areas of groundwater recharge, flood retention, and
maintenance of base flow in streams.
The GRCA is a partner in
the Durham Region Coastal Wetland Monitoring Project, which is designed
to utilize standardized monitoring protocols to assess the long term
health of the wetland systems. Monitoring efforts are focused on all
aspects of wetland health, including water level, water quality,
sediments, plants, and macroinvertebrate, amphibian and bird
Coastal wetlands have unique functions that are performed naturally:
Interception and slowing of watershed run-off before it enters the lake allowing:
- Settlementation and retention of sediments and contaminants (such as heavy metals and PCBs).
- Reductions of excess nutrients as wetland plants absorb nitrogen and phosphorus and use them for growth.- Provision of habitat for microbe and invertebrate species, thereby providing the foundation for a complex food web. These food sources, along with the wetland plants, in turn support a wide variety of fish, reptile, amphibian, mammal, and bird species.
These natural wetland functions translate into important societal values:
- Opportunities for recreational activities including canoeing, fishing, hunting, wildlife viewing, and photography.
- Protection of shoreline properties from the potentially destructive forces of erosion.
- Improvement of water quality for the millions of people in Canada and
the United States who rely on the Great Lakes for their drinking water.
A watershed is an area of land that drains water to a particular point, which in the Ganaraska Region Conservation Authority watersheds is Lake Ontario. The purpose of watershed planning is to develop locally driven plans that will create a framework to guide the conservation, management, rehabilitation, and enhancement of the watersheds and their resources. This process is needed for sound land use planning and is required under the provincial Oak Ridges Moraine Conservation Plan. The topics covered within a watershed plan include groundwater quantity and quality, surface water quantity and quality, terrestrial natural heritage, acquatic habitat and species, public health and well being, and community heritage.
In 2009, the Cobourg Creek Watershed Plan was finalized. The Cobourg Creek Technical Review Committee and Community Advisory Committee have provided valuable review and input into the watershed plan. Two key documents have been created through this initiative, the Cobourg Creek Background Document: Abiotic, Biotic and Cultural Features and the Cobourg Creek Watershed Plan.
In 2010, the Ganaraska River Watershed Plan, Wilmot Creek Watershed Plan, Graham Creek Watershed Plan, and the Lovekin Creek, Bouchette Point Creek and Port Granby Creek Watershed Plan were all finalized. Each of these watersheds also engaged a Technical Review Committee and Community Advisory Committee that provided valuable reviews and inputs into the watershed plans.
Each of these initiatives is supported by a Background Document: Abiotic, Biotic and Cultural Features.
Wilmot Creek Background Report
Graham Creek Background Report
Lovekin Creek, Bouchette Point Creek and Port Granby Creek Background Report
The next step after the development of the watershed plans is plan implementation. This step is seeing the recommended mangement actions realized throughout the watersheds. Plan implementation occurs through the many partnerships between the Ganaraska Region Conservation Authority, local municipalities, agencies, stakeholders and residents.
To learn more about watershed planning , or to become involved in plan implementation please contact the Ganaraska Region Conservation Authority at 905.885.8173 or email@example.com
|Private Wells and Permit To Take Water (PTTW)|
Local Private Water Supply Wells
The majority of the water supplies in the GRCA watersheds are private wells used as domestic water sources. These domestic wells are located throughout the area, except where municipal water systems are available. Many of these wells supply water to permanent residents, cottages, and summer homes in rural areas. Some wells are also used for agricultural purposes including livestock watering and irrigation, and others are also used for commercial and industrial purposes.
The GRCA Watershed Hydrogeologist provides technical support to the watersheds residents in caring and maintaining their wells in a good working order. This is done by conducting site visits, answering well owner’s questions, referring water sampling to Health Units and Departments, providing educational materials and conducting safe groundwater seminars across the GRCA.
Safe Groundwater Seminars
The GRCA, in partnership with the local municipalities and local Health Units/Departments, organizes Safe Groundwater Seminars across its jurisdictions from time to time. The seminars are designed to provide information and educational materials to home owners who rely on private wells as water supply systems, who have septic systems. The seminars are presented in partnership with public agencies and are aimed to assist and educate residents of rural areas within GRCA watersheds. GRCA also invites licensed local water well contactors and consultants to participate in these seminars with displays showing equipment and services available to local area residents.
PTTW Applications and Planning Reviews
Part of the Watershed Hydrogeologist responsibilities includes the review of planning, development, and land use change applications within the GRCA watersheds as they relate to the groundwater regime. It also includes review of technical reports and evaluates potential hydrogeological and groundwater resources impacts of proposed and existing water taking permits. The GRCA has a technical team organized to respond to the Ministry of the Environment (MOE) on all of the submitted Permit To Take Water (PTTW) applications (new applications and renewal), which are located within the authority’s jurisdictions. Technical responses to MOE are normally done in consultation with the local municipalities.