This file represents an aggregated dataset that shows previously active Orders and Alerts in the Province as initiated by Local Governments or First Nations. Start dates, re-installment dates and All Clear Dates for each Evacuation Order and Alert are included in this multipart polygon dataset. The dataset includes records beginning summer 2017 until the present day. Orders and Alerts that are currently active are found in [Evacuation Orders and Alerts](https://catalogue.data.gov.bc.ca/dataset/evacuation-orders-and-alerts).

The annual maximum and minimum daily data are the maximum and minimum daily mean values for a given year.

The annual maximum and minimum instantaneous data are the maximum and minimum instantaneous values for a given year.

The daily mean is the average of all unit values for a given day.

Historical hydrometric data are standardized water resource data and information. They are collected, interpreted and disseminated by the National Hydrological Services (NHS) in partnership with the provinces, territories and other agencies through the National Hydrometric Program. These data sets include daily mean, monthly mean, annual maximum and minimum daily mean and instantaneous peak water level and discharge information for over 2700 active and 5100 discontinued hydrometric monitoring stations across Canada.

The monthly mean is the average of daily mean values for a given month.