Common SuDS Faults

Based on feedback from a range of MGSDP partners, the list below is a compilation of the most common faults / problems / defficiencies in the implementation of SuDS, which will lead to a protracted handover / adoption / vesting process and usually additional costs for all parties.

Please take the opportunity to review the list and avoid making some of the same mistakes others have made... 

1. Poor standard of construction - not complying / aligning with design dwgs.

2. Lack of knowledge of design requirements / guidelines.

3. Lack of detailed information provided during design process.

4. Failure to consider SuDS / drainage at the start of the project design, resulting in poor design.

5. Poor consideration of ecology, biodiversity and placemaking principles in design.

6. Poor construction practices in vicinity of permeable surfaces, including management of soils and materials, leading to silt / sediment / granular material contaminating the permeable surface - this includes over-filling soil beds.

7. Poor landscaping design / detailing, resulting in un-sealed slopes draining downhill towards permeable surfaces, leading to silt / sediment contaminating the permeable surface, which reduces performance.

8. Lack of proactive maintenance of permeable surfaces, leading to silting / vegetation growth and reduced performance.

9. Poor inlet / outlet design / construction leading to vegetation higher than the inlet, which restricts inflow and leads to ponding at the inlet.

10. Side slopes too steep to safely maintain. Where necessary, anchor points should be provided.

11. Failure to undertake appropriate risk assessment to inform fencing / signage strategy. Default position often high security fencing, giving the impression that SuDS are inherently dangerous.

12. Lack of maintenance of private SuDS, leading to reduced performance.

13. Lack of awareness by property management companies of the purpose / function and maintenance requirements of SuDS.

14. Poor liner design / specification and installation.

15. Inlet and outlet set too close together, resulting in short-circuiting.

16. Lack of safe access to all elements of the SuDS system for inspection and maintenance, including parking / turning vehicles.

17. Poor vegetation species selection resulting in high maintenance burden.

18. Failure to provide as-builts drawings that identify both the usual operating depth as well as the maximum potential water depth.