Streamflow & Water Levels

Streamflow and water level data are used to monitor flood and drought events. They are also used to monitor water supply for lake operation and navigation. This information is used to determine flood risk, support land use planning, assess fish habitat and for water quality analyses of contaminant loading.

Streamflow

Streamflow information is collected at 8 different locations along the Rideau River, Jock River, Kemptville Creek, Tay River and Ottawa River. Various agencies (Parks Canada - Rideau Canal Office, Environment Canada - Water Survey Division, Ministry of Natural Resources and Forestry and RVCA) are involved in the collection of the streamflow data.

Water levels

Six water level stations are found throughout the watershed along the Rideau River and on Big Rideau, Bobs, Wolfe and Upper Rideau Lakes. Data is collected using electronic continuous recording units. A sensor reads the water levels usually at one hour intervals and that data is recorded in a “data-logger” that can be downloaded at the site or transmitted to the RVCA by telephone, radio or satellite communication.

Manual measurements of water level can also be done by placing a measuring device or “staff gauge” in the river attached to a bridge or somewhere so that the gauge is always in the water and can be easily read by an observer. Manual measurement of water level are very useful in documenting rare events and calibrating numerical models.

Precipitation

Precipitation is the total amount of water that falls on the ground in the form of rain, snow and hail. Part of the precipitation flows on the ground towards rivers, part of it seeps down into the ground, and part of it goes back to the atmosphere through evaporation and transpiration by plants.

Precipitation information is collected to help understand its impact on streamflows, water levels and low flow conditions. Precipitation data is used by the RVCA in flood forecasting, flood risk assessment and drought analysis and by others for such things as reservoir management, agricultural activities, road system and storm water management and recreation planning.

RVCA looks to six stations where precipitation data is being collected on a long term basis:

• Ottawa Airport (since 1938)
• Russel (since 1954)
• Brockville (since 1965)
• Drummond Centre (since 1984)
• Godfrey (since 1981)
• Kemptville (since 1928)

Additional information is compiled from volunteers who have joined our Rain Gauge Network. We provide the rain gauge and volunteers supply the readings. Learn more about the Rain Gauge Program.

Snowpack

Snowpack is the accumulated snow cover on the ground. A significant portion of the total precipitation that falls on the Rideau Watershed is in the form of snow.

Snow measurements are done on or about the 1st and 15th of each month from the beginning of December to when the snow is gone in March or April. Five locations are monitored by the RVCA in the lower watershed east of Smiths Falls and another six in the upper watershed are monitored by staff of the Rideau Canal Office of Parks Canada.

Water Chemistry

The Rideau Valley Conservation Authority monitors water chemistry at 57 stream locations and approximately 39 lake locations for a total of 409 sampling sites throughout the Rideau watershed on a routine basis.

The three water chemistry monitoring programs are:

• Provincial Water Quality Monitoring Network
• RVCA Baseline Monitoring Program
• Watershed Watch

Information on water chemistry is available through our catchment and subwatershed reports and our interactive mapping tool.

Provincial Water Quality Monitoring Network (PWQMN)

This program looks to provide a consistent baseline dataset that can give a general indication of water quality in the watershed. Details: Provincial Water Quality Objectives.

• 10 sites throughout the watershed ( 6 sites are in common with the City of Ottawa monitoring program and 3 with the RVCA baseline program which increases the total dataset for those sites which can allow more detailed assessment)
• 8 times per year about once a month spaced to collect samples from the complete range of flow conditions from April to November
• 36 sample variables including nutrients, metals and ions

RVCA Baseline Monitoring Program

The RVCA Baseline Monitoring Programs looks to assess the contribution of tributary streams to loadings in the Rideau River and upper watershed lakes. It also monitors ambient conditions at locations on major tributary streams.

• 56 sites in total
• 8 times per year about once a month spaced to collect samples from the complete range of flow conditions from April to November
• 31 sample variables including bacteria, nutrients, metals, dissolved solids and ions

Watershed Watch Program

The Watershed Watch Program samples the 39 major lakes in the watershed on a regular cycle to help identify trends in water quality. The program relies on volunteers to help with water transport or boat/canoe access points. Learn about getting involved in the Watershed Watch Program.

• average of 8 sites (varies each year depending on lakes); 1 site at lake deep point (surface and bottom samples, dissolve oxygen/temperature profiles), average 4 inshore sample sites near possible pollution source points/areas
• samples taken once in May, September, October; twice during summer months (June-August)
• sample variable include total phosphorous (TP), total Kjeldahl nitrogen (TKN), dissolved organic carbon at deep points; TP,TKN, Eschericia Coliform (E.Coli.) at inshore sites (sampled at half metre depth in approximately one metre of water)

Water Biology

The Rideau Valley Conservation Authority has sampled benthic invertebrates since 1997 at various sites throughout the watershed. These efforts compliment the RVCA's extensive water chemistry sampling program. Benthic invertebrates are great barometers of pollution. Some can tolerate pollution while others are very sensitive to instream pollution. By sampling stream-bottom invertebrates the program can determine changes in stream water conditions and levels of pollution over time.

As part of the Ontario Benthos Biomonitoring Network (OBBN), RVCA staff follow a provincial protocol for sampling in streams, lakes, and wetlands. A total of three replicates of samples are collected at each of the site locations and are brought back to the RVCA lab for identification. Once identified the samples are run through various indices, which are then analyzed and observations can be made. Overtime trends and patterns of the data can be studied and water quality issues can be addressed by using best management practices in areas of concern.

Results from our water biology sampling can be seen in catchment and subwatershed reports.

VIDEO: Benthic invertebrate sampling in the Jock subwatershed