LETTER: My expert take on Boston Barrier


I’ve taken a keen interest in the Boston Barrier since I arrived in the area in 2004. Although I am now retired I was an engineering consultant for a number of years on similar projects in the UK and abroad.

I believe the people of Boston should know what they are getting. All the following is based on information provided by the Environment Agency (EA), my personal experience or both.

Those of us who attended the November 2011 EA exhibition were given to believe that the waters upstream of the new barrier would be retained all summer, from Easter through to the end of September.

The EA claimed that because we would not see the dirty brown river a large tourist income would come to the town. I sent a letter to our MP who forwarded it to the EA because I was most concerned that such a proposal would end up with both Boston and the Witham catchment area flooded. We are now told that this demonstration was only ‘indicative’.

The EA now confirms that due to the requirement for river flow, based on historic records, they hope to retain the water 70 per cent of the time.

This means that on average, one in three tides, the water will have to be released approximately five hours prior to low water and will not be able to be retained for 10 hours, showing the dirty brown stuff.

To obtain this advantage it will no longer be possible to take a boat from the marina to the Wash because the new barrier will prohibit this as it will not have a lock. It appears to me tourist revenue is likely to go down rather than up.

We as ratepayers are to contribute £11 million to this project because it will provide a boat link. The link already exists for small boats but not for canal boats that are longer than the lock. These require both sets of the Grand Sluice lock gates to be open at once. It was claimed this would be available when the new barrier is in place because the retained water level downstream of the lock would be the same as the level upstream. This may be the case for a short time, but as the river flows from Lincoln it will not be the case for long.

We are told that the barrier will protect Boston from future events, such as happened on the December 5, 2013. Again a half truth. It is most unlikely that the Stump would have been flooded, or anywhere else in that area.

But the water also came through at the docks, which are downstream of the new barrier site and would not have been protected.

When the water hit the barrier it would have risen up, through the docks and over the walls, just flooding a different part of Boston. In recent weeks I have had confirmation from the EA that ‘The Boston Barrier will be constructed to a level of 7.3metres AOD. At the same time the barrier is built, as part of the associated works, the walls and wet lock entrance of the Port of Boston will also be raised to 7.3metres AOD and the downstream banks all raised to 6.3metres AOD. Therefore the port will have a better standard of protectiont’. Providing this is done, at considerable expense, before the barrier is commissioned, one of the purposes of the duel purpose barrier may be achieved.

I have also asked the EA why we cannot have the barrier four miles from Boston at the end of the Haven. I am told that ‘A barrier at the mouth of The Haven was discounted by the Boston Combined Strategy (BCS) because of the impact of a multi-functional barrier on commercial shipping (port and fishermen).

The mitigation, a large lock next to the barrier, was also identified as unacceptable by those affected’. This would have been prior to 2004.

Back in 2010 we were asked to attend an exhibition designed to decide where the barrier should go. I had no knowledge of what had gone on before, or even that a multifunctional barrier was required. I walked in and told the EA representative, ‘None of these’.

I was introduced to their consultant who was expected to persuade me that I was wrong. Instead I was asked to provide a design brief (for free) for a barrier at the obvious point, at the end of the Haven.

A pity the consultant then gave up the project. My proposals would have answered all the criticisms above and I am sure would be less costly than the present proposals. To make my proposals work all that would be required for the boat link is an extension to the barrel to accommodate canal boats.

My proposals would set the retained water level at just above low tide level (as at other sites in the UK where I have been involved)

This could be retained without a brown river in sight. It would also have an extra purpose, keeping the tide out when the catchment area of the Witham is swamped (as happened in 2007) allowing a much faster release of flood waters probably making the Black Sluice pumping station redundant.

It appears that the project was set in stone before 2004 by the BCS and now it will not be changed even though it will not do as it says on the tin.

David Matthews

Churchgate, Boston