Design levels from KSA 6997-KSA-03-XX-DR-C-0001 S4-G · to be updated to as-built at handover
IMPERIAL FIELDS – RESIDENTIAL BLOCK
Drainage chamber record · Bishopsford Road, Morden SM4 6BF
SURFACE WATER
S3.17
Precast concrete manhole 1800 dia - FLOW CONTROL CHAMBER
⚠ CONFINED SPACE – NO ENTRY WITHOUT PERMITPermit to work · gas monitor · trained operatives · top-man & rescue plan. Most tasks can be done from the surface.
Key data · levels: design (KSA S4-G)
Cover level20.450
Invert level19.100
Sump level18.700
Depth to sump1.750 m
Pipe225 Ø
Cover classD400
Flow control3.0 l/s
Design head1.450 m
NoteFLOW CONTROL: vortex unit 3.0 l/s, design head 1.450m, emergency drain-down & overflow pipe. Outfall to ditch IL 19.000 with non-return flap
Section through chamber
Where it is
Extract of KSA drainage layout – S3.17 circled red.
Inspection & maintenance
Carried out byAppointed third-party maintenance team
- Every 6 months and after heavy storms: lift cover and inspect from the surface – vortex inlet clear, no debris on the overflow.
- Remove silt from the sump by vac tanker when it reaches about 1/3 depth.
- Jet the outlet and check the outfall non-return flap at the ditch opens freely.
- Yearly: operate the emergency drain-down; check the vortex unit for damage.
- Do not remove or adjust the vortex unit – it sets the permitted discharge (3.0 l/s).
- Record every visit in the log below (date, name, findings, action) with photos.
CCTV survey
Report refTo be completed at handover
Survey date—
Video—
Handover record – where CCG finished
Practical CompletionTo be completed at handover
Defects period endsTo be completed at handover
Handover inspectionTo be completed at handover
Condition at handoverTo be completed at handover
Silt at handover—
As-built levels verifiedTo be completed at handover
ID plate fittedTo be completed at handover
Inspection log
| Date | By (company / name) | Silt / condition | Action taken | Next due |
|---|---|---|---|---|