Briefing note for Canalside residents and businesses 16.10.20

Update for residents and business operators within Canalside and the immediate surroundings following Storm Dennis and the associated flooding (16.10.20)

Introduction & background

On the 16th February 2020, many areas across Wales were subjected to serious adverse weather conditions in the form of Storm Dennis. Unfortunately, a large number of both residential and business premises were affected by flooding as a consequence, and one such area which was seriously affected was Canalside. Since that date, flood authorities have been exploring options to reduce or even prevent flooding going forward. This was confirmed in a meeting held with residents and business operators at the golf club on the 31st July 2020, where Neath Port Talbot council (NPT) and Natural Resources Wales (NRW) gave an undertaking to continue exploring those opportunities and provide feedback. This update is intended to provide information associated with the flood investigation which took place following the storm, in addition to the options which both NPT and NRW are currently pursuing.

Flood investigation

Following the storm event and the associated flooding, NPT as the Lead Local Flood Authority took responsibility for preparing an investigation report in accordance with Section 19 of the Flood and Water Management Act 2010. This report was prepared in association with other flood authorities including NRW and Welsh Water (WW). It is a public document and has been made available to the residents of Canalside.

The comprehensive investigation report confirms that rainfall peaked at 4.4 mm per hour at 15.00 on the Saturday afternoon with the river levels reacting 4.30 hours after, peaking at 18.30 hrs. Unfortunately rainfall peaked again at 9.8mm per hour at 23.00 hours on Saturday followed by a further peak at 03.00 hours on Sunday morning leading the river to rise to the highest on record at 05.15 hours.

During this period, a multi-agency response was implemented in accordance with the Emergency Response Plan and residents were assisted to evacuate their properties. Following the flood event, support was provided to residents to help with the clean-up operation and compensation was also provided to those affected.

The investigation which followed identified that flooding to the properties came from a number of sources/directions namely;

1. The river overtopped under the A465, after which water travelled along the footpath and entered the canal. This in turn led to water overtopping the walls of the canal and flooding residential properties at Canalside via the front entrances.
2. The combined sewer was flooded leading to the failure of the pumping station and associated surcharging which affected the rear of properties.
3. Due to the excessive rainfall and the above flood events, the ground became saturated which resulted in ground water levels rising beneath the properties.
4. As a consequence, the properties on Canalside were affected by flooding from three different directions.
   The report goes on to outline a number of actions to consider by the different flood agencies which
   are summarised as follows:
   1. The Flood Incident Response Plan to be reviewed and updated where necessary.
   2. A meeting is to take place with all responsible stakeholders to discuss future flood mitigation
   options.
   3. WW to consider implementing any agreed recommendations.
   4. NRW to consider implementing any agreed recommendations.
   5. Cadw to consider implementing any agreed recommendations.

As a consequence of this report a number of actions have been completed which are as follows:

Update on actions

1. A multi-agency meeting was held on site with residents on the 31st July 2020 to capture the concerns of residents and consider potential options to address these concerns. A follow up meeting was arranged on the 16th October to discuss progress.
2. The Emergency Evacuation Plan has been reviewed and updated. A copy has been provided to all relevant emergency services and a public copy will be delivered to residents shortly.
3. A meeting took place on the 7th October which was attended by representatives from Welsh Government, Neath Port Talbot Council, Natural Resources Wales, Welsh Water, and Cadw. At that meeting the following were agreed as options which would be considered further:
   • a. NPT to scope out a location to site a storage container at Canalside which does not obstruct access to residents and emergency services nor worsen flooding. This container will be filled with sandbags and a trolley to mobilise the sandbags. The container will be secured with a combination lock, the details of which will be provided to residents. To be completed before 31st October 2020.
   • b. The drainage section within NPT is seeking additional funding to expand the number of officers available on standby when intelligence confirms a storm event is forecast. These officers will support implementation of the Emergency Plan in addition to supporting those potentially affected during and after a flood event.
   • c. NRW to discuss with residents and then examine procuring external consultants to survey and potentially implement a property level solution which could include flood gates and other appropriate mitigation. This would include input from WW given the surcharging that was previously experienced by residents. WG confirmed funding is available to undertake this piece of work. This procurement work will take 3 to 4 months.
   • d. Work to raise the level of the footpath near the A465 to be considered by NRW. This could contain a limited increase in water within the river channel for longer. If implemented, this work could be complete within a few months.
   • e. NRW to develop a Strategic Outline Case (SOC) which will assess the viability of options to reduce the risk of flooding to Aberdulais. The production of the SOC is in the process of being commissioned by NRWs Projects Delivery Team and is anticipated to be completed by the end of this financial year.