EPA HydroNet - Data Types

The various types of data that are available on this website are outlined below, together with particular points that should be noted in relation to potential problems with data reliability.

Instantaneous Data for the last three months.

These values are the instantaneous values of water level, taken at 15 minute intervals, for the last three months. The flow values are calculated using the appropriate rating curve.

In the case of the stations that are on telemetry, the data at these stations are downloaded at 5:00 AM (GMT) each day.

Recently downloaded data may not be validated and will have an unchecked quality code and caution is required prior to using such data.

Daily Mean Data for the last year

These are daily mean values of water level or flow for the past year, with the flow values calculated using the appropriate rating curve.

Daily Mean Data for the period of Record

These are the daily mean values of water level or flow as calculated for each day in the period of record, with the flow values calculated using the appropriate rating curve.

DATA

Introduction to Quality Codes

Data is provided using the digitising of the water level records or the data logger values and the rating curve(s) that has been drawn through the list of measured flows that were carried out on site. Flow data that are outside the range of measured flows are based on an extrapolation of the rating curve and should be used with caution.

Data Quality Codes

1.Instantaneous data – 3 MONTHS

The following primary flags are implemented in the time series flagging system:

2. Daily mean data – 1YEAR COMPLETE