Floodplain Mapping 2023
Understanding Natural Hazards and Mapping
The Otonabee Region Watershed
The Otonabee Region Watershed covers 1,951 km 2 , is composed of 8 municipalities, and has 105,000 people living within its boundaries. It spans from the Kawartha Lakes in the North to Rice Lake in the South and from Pontypool in the South-West to Norwood on the East.
Communities across the Otonabee Region watershed are as diverse as the land itself. The City of Peterborough is the largest community with an economic base that includes manufacturing, post-secondary education institutions, health care, and service industries. Many other smaller communities across the rural area support a strong agricultural sector and provide local services.
The main sub-watersheds within the ORCA boundaries are the Otonabee River, Indian River, Ouse River, Rice Lake/Trent River, and the East & West Kawartha Lakes.
Floodplain Mapping Study Areas
There are also several minor sub-watersheds within the Region. We have defined nine high priority study areas where we are creating floodplain mapping:
- NEW - Thompson Creek
- Byersville Creek - COMING SOON!
- Meade Creek
- Curtis Creek
- Jackson Creek
- Baxter Creek
- Lakefield Tributaries
- Kawartha Lakes
- Ouse River, Norwood
Thompson Creek
Floodplain mapping for Thompson Creek is new as of March 2023!
Thompson Creek is located between the Otonabee River and the Trent Canal within the eastern boundary of the City of Peterborough. Thompson Creek has a drainage area of approximately 60 hectares with relatively flat gentle slopes. Flows in the creek are controlled by the Thompson Bay Dam, which is directly influenced by water levels within the Trent Canal. Below the dam, the creek predominately runs through urbanized areas before draining into the Otonabee River.
The red regions on all maps outline the floodplain mapping study area and indicate where the floodplain is.
Meade Creek
Meade Creek is located on the eastern boundary of the City of Peterborough, Ontario. A small portion of the Creek, approximately 9 km 2 , is located within the City boundaries while the rest is located in the Townships of Douro-Dummer and Otonabee-South Monaghan.
Meade Creek's entire drainage area covers 86 km 2 . This floodplain mapping project area includes a smaller 10 km 2 potion of the total area. The study area is located between the Otonabee River and Little Lake, and Burnham Line; Meade Creek flows into the study area as two separate branches (North Branch and South Branch), each crossing Ashburnham Road before flowing into Little Lake and the Otonabee River.
The red regions on all maps outline the floodplain mapping study area and indicate where the floodplain is.
Curtis Creek
Curtis Creek originates in Douro, Ontario draining many of the wetland areas that fall between the drumlin-dominated landscape into the Otonabee River at Tivey Street in the City of Peterborough.
Flooding is one of the biggest natural hazards within the Curtis Creek sub-watershed. This area has a history of flooding after high rainfall events.
In response to this, the City of Peterborough has completed many box culvert and bridge upgrades through the urban part of this system to alleviate flooding concerns.
The original floodplain mapping for Curtis Creek included the undersized culvers and bridges, which caused a massive spill are along the original creek bed along to the Otonabee River. The new mapping extends the study limits to the west, and includes the City's new structures, removing the spill.
The focus for this study area is to create maps that accurately identify areas along Curtis Creek that will flood during a Regulatory Storm.
Jackson Creek
Jackson Creek originates in the Mount Pleasant area of Cavan-Monaghan Township and flows through what is known as the Cavan Bog. These waters make their way to Peterborough along the Jackson Creek Trail and ultimately flow through the downtown core into the Otonabee River.
Jackson Creek's large wetland and swamp areas help dissipate flood waters and impacts downstream. However, due to historical development through the downtown, the Creek has become channelized and its banks and floodplain have been developed.
The study area (in red) is located at the upper portion of Jackson Creek from the Jackson Creek Weir to west of Highway #7 and the eastern edges of the Cavan Bog.
Baxter Creek
Baxter Creek originates near the northern edge of the Ganaraska Forest, flowing northward from the Oak Ridges Moraine and eventually draining into the Otonabee River south of Whitfield Landing.
This is a special cold-water stream that provides habitat for many trout species. Along the stream there is a long history of dam and mill construction dating back to the 1800’s. The re-constructed dam at Needler’s Mill in the Village of Millbrook is owned by Otonabee Conservation.
The study area for Baxter Creek extends from the Otonabee River along the main branch and through the Village of Millbrook (about 28 km). It includes all tributaries (about 49 km), which have an upstream drainage area of 125+ Ha, including the headwater areas of the Oak Ridges Moraine.
Lakefield Tributaries
The Lakefield study area includes Rays Creek and six additional tributaries that encompass the entire community of Lakefield.
These streams all originate in and around Lakefield at the south end of Lake Katchewanooka and either flow into the Lake above the lock or drain into the Otonabee River below the lock. The largest is Ray’s Creek, which will be facing the most development pressure in the coming years.
Floodplain maps in the Lakefield study area will help determine the areas of the Lakefield community that are at risk of flooding in or near the downtown area.
Ouse River, Norwood
The Ouse River originates in the wooded swamps of central Dummer and flows southward where its eastern arm dissects the Village of Norwood, eventually joining its western arm and then the Trent River at the east end of Rice Lake.
The study area for the new floodplain maps has been extended west to the Asphodel 7th Line, eastward to the Asphodel 11th Line, and north to Dummer-Asphodel Road. the Two-Zone Policy area within the Village has not changed.
Kawartha Lakes North & South
The Kawartha Lakes are part of the Trent-Severn Waterway, a historic 386-kilometre canal route that connects Georgian Bay to Lake Ontario. Since the Trent-Severn Waterway is a managed system with dams and locks that is operated by Parks Canada, water flows through it differently than in a natural system.
Along the shoreline of the Kawartha Lakes, the floodline is therefore determined by a known flood elevation. It is defined as the highest water level that has been recorded by Parks Canada.
The Kawartha Lakes North study area encompasses the following Kawartha Lakes:
- Buckhorn Lake (including Chemong, Pigeon, Big Bald, and Little Bald Lakes)
- Lower Buckhorn Lake
- Lovesick Lake
- Stony Lake and Clear Lake
- Lake Katchewanooka
The Kawartha Lakes South study area includes:
- Rice Lake
Flooding in our watershed
During a flood, water levels rise. Areas not normally covered by water may become inundated because of lower land elevation, ice and debris jams, and built development features such as pavement and houses. Flooding poses dangers to people and property.
Riverine Flooding
Occurs when excessive rainfall over an extended period causes the water level within the creek/river to rise and overflow its banks.
Urban Flooding
Can occur when water inundates land or property in a built environment, and when rainfall overwhelms the capacity of the existing storm water infrastructure or drainage systems. There are several types of urban flooding including: street flooding, basement flooding, of low-lying urban areas, and sanitary back-ups.
Photo: Urban flooding of Curtis Creek, Peterborough, ON, 2004
Peterborough Flood 2004
In July 2004, the City of Peterborough's drainage system was overwhelmed with 150 mm of water falling overnight.
The result was flooding all over the city, resulting in $95 million in insured losses. Expenses for city staff responding to the flood amounted to $1.4 million.
Photo: Urban flooding of Jackson Creek in downtown Peterborough, Ontario 2004.
Costs of repairs and restoration for public infrastructure was totaled around $21 million.
In addition, the Province of Ontario provided $25 million for emergency repair and restoration costs for city infrastructure.
Photo: Damaged infrastructure along Jackson Creek in downtown Peterborough, Ontario, 2004.
25 people who were trapped in, or on cars needed to be rescued.
Emergency food was issued to more than 1,000 households.
Photo: Meade Creek at Maniece Avenue, Peterborough, Ontario, 2004.
Firefighters pumped out over 1,868 basements, garages, and backyards.
Photo: Urban flooding, Jackson Creek, Peterborough, Ontario, 2004.
500 homes and businesses had hydro meters pulled from flooded basements and 1,000 homes had gas lines disconnected.
Photo: After the flood of 2004, South Peterborough, Ontario near the Otonabee River.
Why do we need floodplain mapping?
Floodplain mapping is a tool used to protect and respect the floodplain. Floodplain maps help protect property and human life. They are technical documents that are used to guide decisions about land use and development. A map of the floodplain helps to determine where new buildings may be located and if a property is at risk during a flood or storm event.
In some cases, it may be necessary for property owners to take measures to protect existing buildings from flooding. Otonabee Conservation strives to manage the floodplain effectively, and floodplain mapping is an important tool that enables us to do that.
How are floodplain maps made?
Gathering Information
A digital terrain model is a 3D image of the earth's surface that is used as source data and as the background or foundational layer for floodplain maps.
Photo: Digital terrain model of Curtis Creek, Peterborough, ON
On the ground surveys
Ground surveys are then completed to get real time, accurate information on culverts, bridges, and stream flows using the latest survey-grade GPS equipment.
Photo: Data collection on the Ouse River, Norwood, ON
Modelling
A mathematical model is created to represent the hydrology and watershed features. Then a hydraulic model is used to represent additional physical characteristics. Both models are overlain on the digital terrain model. Then, all three models are overlain on aerial imagery to create floodplain maps.
Making it user-friendly!
The final interactive map showing the regulatory floodplain is easy to use and available to the public. Residents and property owners can easily search by their address to see if their property is in a floodplain.
Scroll down to find out how!
Interactive Floodplain Maps
Search for your address!
Explore this map by using the magnifying glass tool in the top left of the map to search for your property and see if you are located near the floodplain.
The red regions on the map outline the floodplain mapping study areas and indicate where the floodplain is.
The purpose of this map is to accurately identify areas that are subject to flooding along river, creek, or lake shorelines. Residents and communities are then better able to prepare for and take action during flooding events.
This map provides residents living along shorelines within the study areas to have information about potential flooding on their property.
Floodplain mapping also helps municipalities and Otonabee Conservation to direct future development outside of the floodplain, avoid loss of life and property damage, and prevent personal injury and stress.
Use the magnifying glass tool to search for your property and see if you are located near the floodplain.
Want to know more?
Check out our Frequently Asked Questions!
When new floodplain mapping is released, we hold a virtual Public Information Centre where we ask for public feedback about the new floodplain maps. We have compiled submitted questions to provide answers to the most frequently asked questions about the mapping.
