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Water and Flood Management

Hydrology is the study of the earth's water and consists of two distinct groups: surface water hydrology and groundwater hydrology, also called hydrogeology. The hydrologic cycle describes the movement of the earth's water through the oceans, land and atmosphere.

Protect Water Image

Hydrology is the engineering science that analyzes the different components of this cycle, and takes into account that the natural cycle can be altered by human and natural activities. Hydraulics is the study of how surface water moves through various pathways in terms of water depth, velocity and pressures acting on hydraulic structures and systems.

Hydrogeology is a science that describes the movement of groundwater (water beneath the ground surface), and its interaction with water that moves on the ground surface in rivers, lakes, streams, and over land. Groundwater seeps into the ground to varying depths and collects in aquifers. Groundwater can remain stored underground for periods ranging from a few days to thousands of years.

Provincial Groundwater Monitoring Network

The Toronto and Region Conservation Authority is participating in the establishment of a province-wide groundwater monitoring network in partnership with the Ministry of the Environment. The network provides an early warning system for changes in water levels caused by climate conditions or human activities and information on regional trends in groundwater quality. As of July 2001, instrumentation for all twelve monitoring wells allotted to TRCA had been installed.

Eventually, professionals and members of the public will be able to access water level and water quality data via the Internet. Water level data will be recorded on an hourly basis and posted every two weeks. Water chemistry data will be collected and posted 1-2 times per year.

TRCA Low Flow Management Program

As water use increases, urbanization continues to expand, and climate change processes develop, management of low or "base" flows in Toronto Region watersheds has become increasingly important. Baseflows are an integral component in maintaining the health and functions of aquatic ecosystems, as well as provide water for commercial, industrial, and recreational purposes.

Low flow monitoring was initiated by the TRCA in 2000. The program focuses on low level flow volumes and distributions, in order to better understand this component of the hydrologic cycle. As well as having regular monitoring sites that are sampled each year, the program also completes extensive baseflow sampling of each TRCA watershed every five years. The Low Flow program strives to establish contact and relationships with water users as a basis for promoting awareness and stewardship activities in their watersheds. Also incorporated into the program is an initiative aimed at mitigating the effects of drought through the implementation of short-term low water conservation strategies which manage both water supply and demand.

The principal objective of the TRCA Low Flow Management Program is to better understand the interconnection between groundwater and surface water systems, and guide the management, enhancement, and resiliency of the surface water component.