Surface water quantity data has been collected and archived in Canada since the middle of the nineteenth century. Beginning in 1908 this data has been published in a variety of printed formats. Since 1991, most of this data has been available on CD-ROM which has replaced hardcopy data publications.

Cooperative undertakings with other government and non-government agencies have been, and remain, an important part of the activities of Environment Canada's water monitoring and data collection. The main instruments for this purpose are agreements with each province and territory for the cost sharing of water quantity surveys. Leadership is provided by Environment Canada in developing technology, methods and standards while data have been exchanged and stream-gauging operations have been facilitated by the assistance and funding received from numerous organizations.

Much of the information about and data from the water monitoring network resides in centrally managed archive databases residing with the Meteorological Service of Canada in Downsview, Ontario. This information is sent to Downsview from the eight regional offices which collect and compile the basic data.

HYDEX is a relational database that contains inventory information on the various streamflow, water level, and sediment stations (both active and discontinued) in Canada. This database contains information about the stations themselves such as; location, equipment, and type(s) of data collected.

HYDAT is a relational database that contains the actual computed data for the stations listed in HYDEX. These data include: daily and monthly means of flow, water levels and sediment concentrations (for sediment sites). For some sites, peaks and extremes are also recorded. The data are collected by the regional offices and updated in the national database once per year. This update generally occurs in the mid-summer for the previous year (e.g. summer 1996 for 1995 data). Each year, a CD-ROM of selected hydrometric data in Canada is produced and is up-to-date to the previous year.

Regional contacts for hydrometric information and data:

• Atlantic Region
• Ontario Region
• Pacific & Yukon Region
• Prairie & Northern Region
• Quebec Region

National contacts for hydrometric information and data:

• HYDEX/HYDAT Database, Technical Support & Client Services
  Champa Neal
  tel: (416) 514-2654
  e-mail: Champa.Neal@ec.gc.ca

• HYDAT CD-ROM
• Analysis Packages:
  1. CFA (Consolidated Frequency Analysis Version 3.1)
  2. Streamflow Toolkit Version 2.0