- General - definitions of the quality flags
- General - how accurate is the data?
- General - how can I download the data?
- General - how often is the Hydrometric data updated?
- General - I have an abstraction licence. Can I use this information?
- General - is all the Hydrological data recorded in Greenwich Mean Time (GMT)?
- General - what is a water day?
- General - what is sub-daily data?
- General - what is the difference between checked and unchecked data?
- Groundwater - what does MAOD mean?
- Groundwater - what is borehole depth?
- Groundwater - what is the difference between dipped, logged and telemetered data?
- Groundwater - why are there sometimes differences between dipped and groundwater telemetered data at the same site?
- Rainfall - how do I download historic rainfall data?
- Rivers - is river flow always a function of river level?
- Rivers - there are differences between the data available on the Environment Agency’s website and the National River Flow Archive, which time series should I use?
- Rivers - what is the difference between river level and river flow?
- Rivers - why do river levels or flow sometimes increase or decrease unexpectedly?
- Rivers - why is 15 minute (instantaneous) flow data only available for a small number of stations?
- Rivers - why is Real-Time Flow data only available for a small number of stations?
- Water Quality - how accurate is the data?
- Water Quality - how are the Water Quality sites selected?
- Water Quality - how do I analyse the data?
- Water Quality - how is the data different to the Water Quality Archive data?
- Water Quality - how often do we take readings?
General - definitions of the quality flags
Created: 19 November 2018 Updated : 30 March 2023
The following flags are used on the website to describe the quality of the flow data.
Good – the data has been manually inspected and there are no obvious or known data issues.
Estimated – a manual change has been made to the data with confidence.
Suspect – a change cannot be made but the data is felt to be inaccurate.
Unchecked – raw input data that has not been inspected manually.
Missing – data has been deleted or never arrived in the archive.
Percent valid – the percentage of 15 min (instantaneous) flow data available to calculate the daily mean.