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Oak Ridges Moraine Groundwater Program

Database periods of record

Time Series Gantt Charts

Gantt charts present the period of record for the variety of long-term monitoring types maintained in the ORMGP database. The charts show the start and end date for each monitoring location. If the line for any given station extends all the way into 2024 on the right side of the chart it indicates that the station is still actively recording data.

It is apparent from the three graphs that climate monitoring was the first monitoring undertaken in Ontario, with the Toronto Station (at the top of the chart) dating back to 1840. It was only in the late 1800s when additional stations outside of Toronto began to track and record climate data. The monitoring of surface water flows began later, in 1860, with flows in the Niagara River being measured since that time. More rigorous stream flow monitoring began in more earnest only in the early 1900s when additional stations were added to the network. The ORMGP database contains some groundwater measurements dating back to the 1950s, however it wasn’t until the 1970s and even into the 1980s before regular recording and storage of groundwater levels began.

In each of the three graphs, the thickest grey line shows, over time, the cumulative number of stations that were actively collecting data around the ORMGP jurisdiction from all sources. For the climate and the stream flow graphs the cumulative counts by year have been broken down by the agency collecting the data. The number of climate stations monitored by Environment Canada is seen to peak at about 300 climate stations around 1970 before dropping off considerably to approximately 50 active stations in 2024. The graph does show an increase in total climate stations now providing data into the ORMGP program, and that is owed to the incorporation of many monitoring locations that are being actively monitored by some of the partner agencies in the ORMGP (e.g., LSRCA, TRCA, and York Region). The number of surface water stations being monitored over the years through the joint Federal/Provincial HyDat program does not show a similar dramatic reduction in the station count, although there has been a slight reduction in the station count in the mid-2000s. The surface water station count has increased in recent years with CVC, TRCA, and LSRCA contributing data into the ORMGP at additional stream flow monitoring locations. For the groundwater gantt chart, the station count has not been divided by the different agencies collecting data.

Note: In each of the graphs, users can hover over a line on the graph to see the name of the station. Users are also able to zoom in on the graph to more clearly see the start and end dates for any particular station. Note that a double click on the chart will zoom out and return the chart to the default setting.

Groundwater monitoring (manual and logger)

Hydrological data

Meteorological data stations