Lately I've been trying to unlock some spatial data held by the Environment Agency related to large raised reservoirs in England.

A large raised reservoir is a structure that holds 25,000 cubic metres or more of water above ground level. In England these reservoirs are regulated by the EA under the Reservoirs Act 1975 as amended by the Flood and Water Management Act 2010.

It's been slow going. I started by submitting information requests in early August 2019, progressed through the internal review stage, then made a complaint to the Information Commissioner's Office.

This week the ICO published two decision notices. One decision is in my favour and instructs the EA to permit re-use of its Large Raised Reservoirs dataset (dataset AfA134) under the Open Government Licence. That dataset contains point locations of reservoirs and details of the organisations responsible for their management.

This is only the third decision notice the ICO has issued for a breach of the Re-use of Public Sector information Regulations 2015.

The other decision upholds the EA's refusal to release polygons for maximum flood outlines for each reservoir (dataset AfA113) and data on maximum flood depths and speeds for the risk of inundation within those outlines.


I'm publishing here, in case of interest, my complaint to ICO and correspondence with EA covering the requests and internal review. I've redacted some names and contact details.

Both parties can appeal the decisions to the First-tier Tribunal, which handles information rights matters.


I am still analysing the ICO decisions and considering next steps. However following are the main issues I see as potential bases for appeal to the FTT.

  • The ICO has supported my re-use request for dataset AfA134. However it has not handled the part of my complaint that relates to access to that dataset under the EIRs. That may be because the EA maintained it provided the data to me in August 2019. I disputed that in both the internal review request and complaint to the ICO. To date, the EA has not released any data to me in response to my access request.
  • Datasets AfA134 (the point locations) and AfA113 (the maximum flood outlines) are both listed in EA's Register of Licence Abstracts with identical conditions for re-use under the Conditional Licence. Why did the ICO decide AfA134 was eligible for release as open data, but that AfA113 should be withheld on the basis of national security?
  • The ICO did not consider the minimum scope of my request for flood depth and flood depth data – equivalent to the spatial data underlying the reservoir layers in online maps published by the Environment Agency. Instead the ICO treated that part of my access request as if it could not be distinguished from the contents of EA's dataset AfA180. That dataset, which I did not mention in my request, contains detailed modelling outputs on inundation risk from reservoirs.

I'll update this post in a few weeks once I know whether any appeals are going ahead.


Update 23 November 2020:

I've appealed both decision notices to the FTT, more or less on the grounds summarised above. The references are EA/2020/0332 and EA/2020/0333.

I've no idea how long the appeal process will take, but the next step is for the ICO to respond by 21 December 2020.


Update 6 December 2020:

The EA has now complied with decision notice IC-64437-V6M6 by supplying to me a report containing information equivalent to the part of my request that related to the Large Raised Reservoirs dataset (AfA134), with permission to re-use the information under the Open Government Licence. I've written about the report in a new blog post.


Update 30 January 2021:

The ICO has submitted an initial response to my combined grounds of appeal. The Environment Agency has joined the case as a party and has until 12 February to respond. After that I have until 5 March to respond to the responses from the ICO and EA.


Update 20 February 2021:

The Environment Agency has submitted its response to my combined grounds of appeal. I have until 5 March to respond to the responses from the ICO and EA. After that the ICO and EA have until 16 April to prepare and submit open and closed bundles.


Update 5 March 2021:

I have submitted my Reply to the Responses from the ICO and EA. The ICO and EA have until 16 April to prepare and submit Open and Closed Bundles. After that we are into Unknown Territory.


Update 14 May 2021:

The ICO has prepared and submitted the open bundle and the ICO and I have each made some further submissions. There is no closed bundle as such, though the Tribunal has received a sample of the information held by the EA. Possibly there will be some further correspondence. The current position is that the Tribunal is considering my appeals "on the papers" – none of the parties has asked for a hearing in person.


Update 19 October 2021:

The Tribunal has dismissed my combined appeal. I understand the decision is likely to be published on the Tribunal's website, so will write a separate blog post about it (with my submissions) then.


Update 31 October 2021:

Here is the Information Tribunal's appeal decision and a blog post about it with copies of my submissions.


Image credit: Ulley Reservoir - DJI Phantom 4 by Darren Flinders (CC BY-NC-ND 2.0)


This post was edited on 15 November 2020 to clarify that reservoirs in England are regulated by the EA under the Reservoirs Act 1975 as amended by the Flood and Water Management Act 2010.