- 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 - what is a water day?
Created: 30 March 2023 Updated: 30 March 2023
All our daily data (mean, max, min and total) are calculated over a water day. This is from 9am GMT one morning through to 8.59am GMT the following day. For example, the day mean on the 1st January is the average of all the 15 min values from 09:00 1st January to 08.59 2nd January.