We were commissioned in November 2023 to assist with planning and designing a development project involving the demolition of garages and the construction of two new dwellings.
Because of the presence of several manholes on the site, it was crucial to conduct a thorough investigation to assess if they were still operational and connected to neighbouring properties.
Project Overview
Project: Garage Demolition and Two New Dwellings Construction
Location: Hayes, Hillingdon
Lead Authority: London Borough of Hillingdon
The project involved overcoming various site constraints, particularly those related to drainage. The presence of a manhole in the access path to the garages and within the proposed foundation area posed significant challenges to the development.
CCTV Survey and Drainage Investigation
To facilitate the drainage design, we arranged for a CCTV drainage survey to investigate the existing drainage network.
Unfortunately, the first CCTV contractor failed to bring the necessary equipment, conducting a superficial inspection by taking photos without properly examining the drainage network, connections, pipe depths, or the condition of the drainage infrastructure. This oversight delayed the project and wasted time and resources for the client and our team.
A second CCTV survey was commissioned to obtain accurate data, including measurements of the manholes and an updated drainage plan. Although this second attempt provided us with the depths and locations of the drainage network, the report was delayed by several months, and critical photographic and video documentation was missing.
Despite these setbacks, we were able to utilize the available data to progress with the design.
SuDS Layout and Drainage Design
Once the drainage network had been assessed, we swiftly moved forward with the SuDS (Sustainable Drainage Systems) layout.
Our design included:
- Rainwater harvesting tanks to promote water reuse
- Permeable paving to reduce surface water runoff during low rainfall events
- Attenuation tanks sized to handle a 1-in-100-year storm event with a 45% climate change allowance
With the drainage constraint resolved, we were able to develop an effective, sustainable solution for the site.
Addressing Contractor Delays and Quality Assurance
The delays caused by third-party contractors underscored the importance of accurate and timely drainage investigations.
The inefficiencies experienced during the CCTV survey process postponed project milestones and compromised the quality of the data received. To mitigate these risks in future projects, we are introducing our own in-house CCTV Surveying Service.
Our New CCTV Surveying Service
Our new service will address the gaps in the current market for drainage investigations. We conduct all CCTV surveys using the latest technology, providing our clients with prompt, high-quality data, complete with video and photographic evidence. By managing the process internally, we can guarantee:
- faster project turnovers
- more accurate drainage designs
- reduced delays.
Our CCTV Surveying Service will enable developers, architects, and engineers to access reliable information essential for effective drainage and SuDS design. With our comprehensive service, you can avoid the pitfalls of contractor delays and ensure your project remains on track.
Further Assistance With CCTV Drainage Surveying
We hope this case study has provided a clear example of how our approach to drainage investigations and design can help streamline your development projects.
If you require more information about our services or want to inquire about our new CCTV Surveying Service, please contact us at info@nimbusengineering.co.uk, 08000614916 or fill out our contact form.
Let us help you ensure that your next project runs smoothly from start to finish with our expert drainage solutions, SuDS report and CCTV drainage survey capabilities.