Managing floods from torrential rain

The Council is currently working on a project to introduce Natural Flood Management (NFM) interventions within the northern woodland area of Holland Park to reduce the rate and volume of runoff leaving the park. 

Natural Flood Management means working with natural processes to reduce the risk of flooding. This includes diverting water to where it is needed or can drain naturally, and this can help increase habitat diversity and provide wider climate resilience. While there are existing hard interventions within the park through Sustainable Drainage Systems (SuDS), which help capture surface water and filter it back into the ground rather than the sewers, these are not able to deal with the fast flow of water from increasingly frequent heavy rainfall down the woodland paths and rainwater still ends up in places where we do not want or need it. 

The hard solutions used on the formal pathways in the park (soakaway drains and bound paths) are not appropriate for the woodland areas and a more natural solution is being sought. The challenges being looked at are: 
• Surface water runoff frequently leaves the woodland area
• Woodland footpaths frequently become preferential flow paths during heavy rainfall, bypassing the absorption of the woodland floor and eroding the tracks.  
• The existing pond within the Wildlife Enclosure receives very little water due to bypassing down the footpaths and therefore requires supplementary top-ups during summer months.  

Solutions are currently going through a design process, and these designs will be ready to share shortly but the interventions may include:
• Earth banks and scraped channels along the woodland paths, with wood or natural stone, to direct surface water flow into the woodland margins and the Wildlife Enclosure pond
• Renewed leaky barriers within the drainage ditch
• Some narrowing of the path on Chestnut and Lime Tree Walks.
• Enhanced woodland margins with additional woodland plants to reduce the footpath catchment and provide additional water infiltration

The woodland paths will remain as an unbound surface. Any earth banks introduced will be staggered and direct water to woodland margins where it can discharge into the soil. 
This project is being supported through funding from the Council and the Environment Agency. It is expected that the work will be carried out in winter 2024 and be complete in Spring 2025. Some pathways may be closed during works for safety reasons, but the interventions proposed work with the natural landscape so any disruption should be minimal. 

Monica Castelino, RBKC Parks Manager

Photos by Jennie Kettlewell

Chairman, of The Friends, Jennie Kettlewell adds that The Friends have been involved in this initiative from the start and wrote to support the bid for external funding (which was successful). While we agree this work is very necessary to retain rainwater in the park, where it is needed, and not let it run off to where it can’t be used, we emphasized that the solution must look natural and retain the integrity of the woodlands. We also asked that it improve the marginal water-dependent habitats. It is pleasing to see the proposed use of earth banks and scraped channels, rather than concrete gulleys. We have asked to be kept informed as the project progresses. 

[September 2024]

Thank you from the Parks Manager

I asked Jennie Kettlewell, your chairman, if I could have a small piece in this edition of the newsletter. This is my thank you to every member of The Friends for the support you provide. My role exists to care for the parks and make them as good as they can be for everyone. This is the core function of my job, but it takes a small army of people from all across the Council and community to truly make this happen.

I don’t take for granted the effort, commitment and support that you all give to the park and its visitors and how lucky we are to have such dedicated friends. 

With your help and support we are making this park more accessible, allowing members of our community who could previously never use the park to visit and feel safe and provided for. We are caring for our trees and giving them the best chance to thrive with a programme of proactive tree health works. And thanks to you the Ecology Centre are able to make their adult education programme free to all. 

So thank you all from me and the team.

Monica Castelino, RBKC Parks Manager

Response from Jennie Kettlewell

I was very pleased when Monica Castelino told me she wanted to write a piece for the newsletter. She is always so busy, yet remembered and found the time. 

We are fortunate to have a great team of Council officers to run our park – Parks Management, the Ecology Service, the Project Management team and the Parks Police. They all work closely together and with contractors idverde. Most visitors comment on how wonderful the park is, and it is wonderful, but they are rarely aware of the sheer quantity of very hard work that goes into making it so. The Friends appreciate being included in all matters related to the park and it is for that reason we can enjoy making a positive contribution.

[May 2024]