Investing in your pool for the future

Pool Maintenance Work

The main swimming pool at the Dolphin Centre will be closed while essential maintenance work is carried out.

The work represents a major investment in the pool, which like the centre marked its 40th anniversary in 2022.

The Dolphin Centre opened in November 1982 and has been open for 40 years.

There have been numerous interventions and changes to the building over the years, the most significant in 2006, which resulted in remodelling of the building, however limited work was carried out on the pool, mechanical and electrical installations at that time.

The pool works forms part of a £3.9m improvements programme delivered over the last four years, which have included the installation of the bowling alley, new soft play and gym refurbishment, as well as improvements in changing facilities.

Although the main pool will be temporarily out of action, swimming lessons and lane swimming will still be on offer in the training pool.

The diving pool and toddler pool will also be available during maintenance on the main pool.

Members have also been given the option to freeze their memberships at any time during the refurbishment works.

Main Pool Closure Update – 11.08.23

Cabinet agreed today to extend the current closure of the main pool to January 2024 to allow the additional works to take place avoiding disruption to pool customers in the future.

Toddler Pool Closure Update - 15.09.23

The toddler pool and exit from the changing village to poolside including the showers on poolside will close from Monday 25th September for the next phase of the works.  The changing village will remain open along with the private showers within the village.  Direction signs and staff will be in the area to show customers the route onto poolside.

Background Information

The programme has experienced a further delay taking us to the end of October due to additional issues identified as part of the demolition works.  These additional works have included:

  • Cracking in the main pool walls that was not evident from the basement side requiring repair.
  • Realignment of the movement joints in the pool floor to ensure that they run parallel with the tiling and prevent future risks of leaks
  • Additional structural repairs and waterproofing associated with the replacement of input pipes
  • Exposure of areas of structural steelwork and application of corrosion protection.  
  • Application of render to correct the misalignment of the pool, the pool requiring squaring up

The removal of the tiles in the main pool in the early stages of the demolition programme identified that concrete cracking and failure of the movement joint waterproofing had led to chlorinated water leaking through the structure and damaging the steel reinforcement in the concrete. 

This informed further detailed investigation works in other areas where deterioration was previously evident but not thought to require works in the near future. With the greater understanding of the issues, it has highlighted the need for further work more urgently than anticipated.

Recommendations from the structural engineer is that this work should be completed within 2 years which will mean a further pool closure projected to take around 6 months.  Although we do not need to complete this work now and could open in October it has been recommended to do this work whilst the main pool is already closed and some of the work can overlap reducing the overall closure time, costs, and future disruption to customers.  This would delay the opening of the main pool to early January 2024.  At this point the toddler pool would remain closed for a further period whilst work in this area is completed but all other pools would be open. 

A decision is to be made by Cabinet in August to confirm if the pool complex will open in October based on the original programme of works or if further investment can be released to enable this second phase of the pool programme structural works to be completed now avoiding a further closure. 

We appreciate this will be disappointing, but the project is very complicated.  Darlington Borough council are committed to ensuring that residents can continue to enjoy their local pool in the future and will continue to provide our temporary pool programme whilst works complete.


What is the problem with the additional areas?

As with the main pool, water has leaked over a long period from the pool onto the supporting concrete structure below. The water penetration has become visible and instigated the maintenance and monitoring programme.

Some concrete beams have corrosion in the reinforcing steelwork due to the chloride in the chlorinated water penetrating into the concrete. (When water penetrates into the concrete over time the steel corrodes and it expands and cracks the concrete reducing its structural strength).

The pools are suspended on the beams above the plant room and as such the structural integrity of the beams must be maintained to ensure it can continue to support the weight of the pool and the water it holds. As such structural repairs are needed similar to the main pool including the use of modern waterproofing technology and construction techniques to the identified areas.

Why weren’t you aware of these works?

The areas were identified but advice was these were not needing urgent repair and could form part of the longer-term maintenance plans.
However, having removed all the tiles on the main pool and having seen how the water has penetrated the structure further investigations have been undertaken which has changed the timescale in which these repairs should be undertaken.

The Cabinet report says a further report is required. Are you anticipating more costs?

Yes, a further report will be brought to Cabinet and Council in September outlining options for the toddler pool, which will be undertaken as part of the proposed extension. We will also have completed some work on a retaining wall, which requires some repairs. There will be further works required in the next 5 to 10 years and these will form part of the ongoing maintenance plans for the building given it is now over 40 years old.

Could the issues be worse than anticipated?

We have based the estimated costs and programme assumptions on what we found in the main pool, but until all the tiles and material is removed to expose the concrete structure we cannot be absolutely sure of what will be found. The experience to date has been factored in as part of the risk and project considerations.

How confident are you that the pool will reopen in January if the additional works are completed?

Based on all the information that we have now, our experience with the main pool and the advice from specialist contractors involved in the project we are confident of a January opening, but until all the tiles and material is removed to expose the concrete structure we cannot be absolutely sure of what will be found. The experience to date has been factored in as part of the risk considerations. We will provide updates as the project progresses.

How does the main pool closure effect my membership?

Members can continue to use the temporary pool programme along with the gym and classes. If you wish to freeze your membership during this period, you can do so by emailing [email protected]

Is poolside completely closed?

The main pool will be closed throughout and the toddler pool will close in October if the additional work is agreed. The training pool and diving pool will still be available - see website for our programme.

How will this work affect the Dolphin Centre?

There may be some limited noise disruption at times but we will keep customers informed.

Which other services are affected?

Existing Dolphin Centre services, gym, classes, sports, soft play, bowling and the Bistro continue as normal.

When will I be able to swim?

Please refer to our pool page for our pool programme.

Do I need to book?

Please refer to our pool page which highlights any sessions that need to be booked.

How do I book?

You can book online using your Dolphin Centre card, or call reception on 01325 406000.

Where will I get changed?

The Changing Village remains open as normal. If the additional work is agreed there may be some changes to access but we will keep customers fully updated.

How do I access the pool?

Access to the pool including accessible change will be as normal. Customers will be informed in advance of any changes to access if the additional work is agreed.

Will the temporary pool programme change?

The pool programme will be monitored for usage and will be subject to change.

Are swimming lessons cancelled?

Our swimming lessons will run as normal, we are committed to continuing our schedule of water education.

Why isn’t the training pool open through the day?

To accommodate the schools water education programme.

Are the slides open?

The slides will be closed for the duration of the main pool refurbishment.

Can children over 8 attend the family swim?

All children must be accompanied with an adult for the family swim sessions.

Can I freeze my membership?

There is an option to freeze your membership. Please speak to reception for details.

How can I contact the Dolphin Centre to find out further information?

Email: [email protected]