The Chronology is provided for the benefit of all with an interest in the past behaviour of British rivers and all elements of the hydrological cycle. Recent years have seen an increased awareness of the variability of hydrological behaviour, resulting from climatic or land use changes, and decision-making is generally considered to be enhanced by the use of historical information regarding the behaviour of hydrological systems. The Chronology aims to improve access to such historic hydrological information through the continuing development of its on-line database.

The Chronology is freely accessible for anyone to search and, if you have access to historic records which would complement our existing data holdings, you are encouraged to consider adding them to the database (but see the Scope information (below) and Data protection page).


The Chronology is intended to contain information which will complement existing instrumental records of rainfall, runoff, snow, etc. It is limited to Great Britain only, and to the years up to 1937 only: no later material can be accepted. It is anticipated that rRecords of exceptional precipitation and runoff events will form the major part of the database, and will be of interest to given their value and significance for hydrological practitioners and researchers when investigating the past variability of British catchment systems.

For extracts from published works, 70 years is regarded as a normal limit for the length of time that copyright prohibits reproduction without permission. However, under the concept of ‘fair dealing’, it is common practice to allow reproduction of short passages of copyright work for scholarly purposes so long as due credit is given. With the Chronology, this requires publication source details to be shown in the ‘Source’ entry, and use of quotation marks as appropriate in the ‘Quotation’ entry.

Contributors are asked to add to the database by drawing on reliable sources, such as:

Guidance for new users

Entries are mandatory for calendar, year, quotation, source and principal river basin(s) to allow the Chronology to work effectively for all users and to allow us to discharge our responsibilities to the original authors of quoted works. Additional information is provided on the Submit Event page to help users.

The ‘related websites’ page allows URLs to direct users to additional sites. Be aware that pages may move – we prefer stable/permanent links where possible. This field can be used to link to photos or groups of images on such sites as Flickr.

The Georeference field can be entered to allow your entry to be found on Google Maps. Lat/Long info can be extracted from Google Maps pages; British National Grid references can be converted.

The Search page allows users to search by the most useful search fields, allowing hydrometric areas, individual watercourse names, dates or events to be searched for. We also have an interactive map to search, and a reference map of the UK hydrometric areas. As at 2016, a tiny number of entries are geo-referenced, but we invite contributors to use this feature when adding new entries, especially if they are site-specific, rather than regional.

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