Sample Method Statement for Dewatering

							                                Project Name
                                                                    Ref. No. :
      Company                    Contract No.
                              Project Description                   Rev.     :
                                                                    Date     :
                        METHOD STATEMENT
                         For DEWATERING                             Page     : 1 of 3




                         METHOD STATEMENT
                                        FOR
                                 DEWATERING




Issue Record.




 0              Issued for approval

 0              Issued for approval

                                                                        Approved    Approved
REV     DATE      DESCRIPTION                 Prepared   Reviewed
                                                                          (JV)     (Consultant)
                                          Project Name
                                                                            Ref. No. :
      Company                              Contract No.
                                        Project Description                 Rev.      :
                                                                            Date      :
                                    METHOD STATEMENT
                                     For DEWATERING                         Page      : 2 of 3


1.0    Introduction

       The purpose of this Method Statement is to outline the activities required for Dewatering of
       certain locations in the raft areas affected by Water Table.

20.    References

       2.1     Project Specifications: Section 02240 - Dewatering.

3.0   Safety

       3.1     Personnel Protection Equipment such as Safety Helmets, Safety/Rubber Boots, Hand
               Gloves, etc will be used at all the times.
       3.2     Proper and sufficient lighting will be provided.

4.0    Procedure

       4.1     Water level encountered is approximately +6.15m in the Raft area. Two areas will be
               affected due to the presence of existing water table:
               -       North-East side of Raft Foundation along Grid Line AX16 – AX09/AY13 – AY10.
               -       South-East side of Raft Foundation along Grid Line AX16 – AX14/AY02 – AY06.

               The top of blinding level for the two areas is +6.170m. The top of Blinding is
               approximately 20mm higher than the existing water table.

       4.2     The following activities will be performed to lower the water table:
               -      200mm x 600mm deep trenches below formation level at approximately 5m centers
                      will be constructed to enable free passage way of water.
               -      Excavate 3.0m external to the Raft Foundation to a depth of 800mm lower than the
                      formation level to place dewatering pumps.
               -      Place 20mm size aggregate in the trench locations and dewatering pump area.
               -      Standby pump will be available at all times inclusive of “permanent pump”.
               -      From experience of sewer line dewatering, lowering the water table by 200mm
                      requires the pumps to be operational at intervals and not continues. Around the
                      clock monitoring of the dewatering and lowering of water table will be carried out.
               -      Discharge of water will be done to existing soak away on Site.
               -      The following activities will be completed prior to stopping the dewatering:
                        Placing of blinding concrete to formation level.
                        Placing of waterproofing membrane.
                        Placing of 25mm screed on top of waterproofing.
               -      The water table will be approximately 50mm below the top of 25mm screed.
                               Project Name
                                                   Ref. No. :
Company                         Contract No.
                             Project Description   Rev.     :
                                                   Date     :
                       METHOD STATEMENT
                        For DEWATERING             Page     : 3 of 3




   Formation Level                 = 6.095

   Top of Blinding Level           = 6.170


   Water Level – 8th August 2002

   -      06:00 a.m.       6.098
   -      08:00 a.m.       6.096
   -      10:00 a.m.       6.090
   -      12:00 noon       6.085
   -      02:00 p.m.       6.089
   -      04:00 p.m.       6.094
   -      06:00 p.m.       6.097