NRFA Peak Flow Dataset Version 13 Released

Submitted by Gayatri Suman on

The National River Flow Archive (NRFA) has released an update to the national Peak Flow Dataset. The dataset of peak river flow data and information consists of the files for use in the WINFAP software for flood estimation and updates to the accompanying metadata. The dataset includes Annual Maxima (AMAX) and Peaks Over Threshold (POT) data for 921 gauging stations of which 617 are in England, 174 are in Scotland, 92 are in Wales, and 38 are in Northern Ireland. The data from individual river flow gauging stations are categorised by their indicative suitability which relates to the hydrometric quality of flow data. A total of 543 stations are recommended for use in pooling groups (‘Suitable for Pooling’), 354 stations are ‘Suitable for QMED’ and 24 stations are ‘Suitable for Neither’. 

Version 13 contains: 

-Network changes (addition, removal, closure and reopening of gauging stations)
-An additional water year of data (updated to 30th September 2023) for all active peak flow stations in the UK 
-Full period of record data and metadata review for a subset of stations in the dataset (98 stations)
-Modifications to existing time series  

Amongst the changes, 12 new stations were added to the Version 13 Peak Flow Dataset: 

New AMAX records (AMAX 1, the highest ranking in the period of record) were established at 12 stations during water year 2022/2023 in Scotland and southern England.

As well as the additional water year of data, an extensive review of period of record flow and stage data, gauging and rating data and associated metadata (e.g. POT threshold, station description, rating history, missing data periods, FEH Indicative Suitability, rejected years) was undertaken for 98 stations (23 stations in Scotland, 61 stations in England, and 14 stations in Northern Ireland). For Wales, a review of metadata, gaugings and ratings was conducted at 28 stations, sense checking the datum histories and the consistency of data and metadata holdings. Furthermore, digital start dates were updated for all stations in Wales, and a review of photograph holdings and captions was conducted for sites in England. During the Period of Record Review almost 4,500 years of data were reviewed!

Download Version 13 of the NRFA Peak Flow Dataset

A list of stations that were included in this year’s period of record data review can be found in the release note of the NRFA Peak Flow Dataset.   

The NRFA’s Peak Flow Dataset provides flood data for 921 river flow gauging stations across the UK. The data can be used with the flood estimation methods set out in the Flood Estimation Handbook (FEH), which is the industry standard for current flood estimation in the UK. The Peak Flow Dataset has been shown to provide net economic benefits of almost £5.4 million per year in terms of costs saved by environmental consultants and regulators.

The peak flow data provided through this service originate from gauging stations operated by a range of UK hydrometric Measuring Authorities as is the case with other NRFA data. Maintenance of the NRFA Peak Flow Dataset, including the latest update, is carried out under a collaborative project between the UK Centre for Ecology & Hydrology, the Environment Agency, Natural Resources Wales, Northern Ireland’s Department for Infrastructure – Rivers, and the Scottish Environment Protection Agency. 

The updated NRFA Peak Flow Dataset (Version 13) was released on 29th August 2024 and reflects the NRFA data holdings at this time. It is the tenth version released since the NRFA took stewardship of the national Peak Flows database. Updated peak flow time series and metadata are now available to view on the NRFA website and can be found using the NRFA’s gauging station search tool. 

More information about the update can be found in the Version 13 release note.