Development Application Part 3 of 3 - Plans · OPW11/0320

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                                              GRAZE TO BE GEOFABRIC
                                                                                                                                             SEDIMENT AND EROSION
                                              INTA PED.
                                                                                                                                                CONTROL DETAILS
                                                                                                EARTH BOND CONSTRUCTION NOTES
                                                                                                1. BUILD WITH GRADIENTS BETWEEN 1 PERCENT AND 5 PERCENT.
                                                                                                2. AVOID REMOVING TREES AND SHRUBS IF POSSIBLE - WORK AROUND THEM.
                                                                                                                                                                                                                                     TRAPPED SEDIMENT
                                                                                                3. ENSURE THE STRUCTURES ARE FREE OF PROJECTIONS OR OTHER IRREGULARITIES THAT COULD IMPEDE                                                    TURF STRIPS
                                                                                                    WATER FLOW.
                                                                                                3. BUILD THE DRAINS WITH CIRCULAR, PARABOLIC OR TRAPEZOIDAL CROSS SECTIONS. NOT V SHAPED.
                    KERB INLET PROTECTION                                                       4. ENSURE THE BANKS ARE PROPERLY COMPACTED TO PREVENT FAILURE
                                                                                                5. COMPLETE PERMANENT OR TEMPORARY STABILISATION WITHIN 10 DAYS OF CONSTRUCTION.
                                   NTS



                                                                                                                       DIRECTION OF FLOW


                                                                                                                                                                                                           TYPICAL GRASS FILTER STRIP DETAIL
                                                                                                                                                           BATTER GRADE                                                              N.T.S.
                                                                                                                                                           1:2 max.

                                                                                           CHANNEL STABIUSARON                     -'I =
                                                                                                                                                                                                                                                                                                                            0
                                                                                                                                                                                                                                                                                                                            0
                                                                                                                   NOTEe-                                                                                                                                                                                                   0
                                                                                                                   Min. GRADE 0.25%                                                                                                                                                                                         V
                                                                                                                   Max. GRADE 0.75%
                                                                                                                   MUST HAVE A STABILISED OUTLET.
                                                                                                                   MAYBE USED AS CONTOUR DRAINS




                                                                                                                                  CAN BE CONSTRUCTED WITH
                                                                                                                GRADIENT OF DRAIN OR WITHOUT CHANNEL
                                                                                                                                  /               ALL BATTER GRADES
                                                                                                                1% to 5%                                                                                                                                             SURFACE ROUGHENING
                                                                                                          Umccuun
                                                                                                          OF FLOW



                                                                                                                                                                                                                                                                                         15LMY
                                                                                                                                                                                                                                                                          150 MM MIN.    1 I 500 MM MIN.
                      GRASSED FILTER STRIPS                                                                          L2 metres min. -^I
                                                                                                                 NOTE: ONLY TO BE USED AS TEMPORARY BANK
                                                                                                                 WHERE MAXIMUM UPSLOPE LENGTH IS 80 METRES.

STORMWATER TREATMENT DETAILS                                                                                  EARTH BUND CUT OFF DRAIN                                                                                                                                       ROCK TRENCHED 200 MM INTO GROUND

SEDIMENT FLOCCULATION
The job of a flocculent Is to effectively break down the dominance of the clay particles that contain a residual negative eIeCIRCUITro-magnetic charge and thus allowing individual particles                                                                "ZC
to be drawn together and settle under gravity.

METHOD OF APPLICATION                                                                                                                                                                                                                                                                                                 cc)
Large sediment basins such as the one this site, require that the gypsum is mixed Into a slurry with water and then sprayed over the surface of the turbid water In the sediment
                                                                                                                                                                                                                                                                    SPACING OF CHECK DAMS ALONG CENTRELINE      ^.q   N
                                                                                                                                                                                                                                                                    AND SCOUR PROTECTION BELOW EACH CHECK
basin.  H Is essential that the gypsum Is spread evenly over the entire surface for efficient treatment of the turbid water.                                                                                                                                        DAM TO BE SPECIFIED ON SWMP/ESCP
Generally the gypsum should be applied at a rate of about 32 kgm per 100 cubic metres of detained turbid water, as per the adjacent table. The above dosing rate for the site                                                             ROCK CHECK DAM
should be calibrated after the first two storm events to assess the actual flocculent application rate and settling time required for the site.
The final application rate should be sufficiently high to permit adequate sediment sediment flocculation (less than 50 NTU) and basin dewatering within two days (48 hours) from the
conclusion of each storm event, whilst maintaining other required water quality criteria such as pH (6.5 - 8.5) and dissolved oxygen (>80%).                                                    ROCK CHECK DAM CONSTRUCTION NOTES
                                                                                                                                                                                                1. CHECK DAMS CAN BE BUILT WITH VARIOUS MATERIALS, INCLUDING ROCKS, LOGS, SANDBAGS AND STRAW BALES. THE
METHOD OF TESTING THE STORMWATER                                                                                                                                                                    MAINTENANCE PROGRAM SHOULD ENSURE THEIR INTEGRITY IS RETAINED, ESPECIALLY WHERE CONSTRUCTED WITH STRAW
The stormwater detained In the sediment basin will be tested at a suitable location that will be decided upon at the alto. The sample should be taken at a location that has adequate               BALES. IN THE CASE OF BALES. THIS MIGHT REQUIRE THEIR REPLACEMENT EVERY TWO TO FOUR MONTHS.
access so no sediment Is resuspended while the testing is being conducted.                                                                                                                      2. TRENCH THE CHECK DAM 200 MM INTO THE GROUND ACROSS ITS WHOLE WIDTH. WHERE ROCK IS USED, FILL THE
The stormwater detained In the sediment basin will be tested with the TIPS 90-FLT water quality logger.    The TPS 90-FLT unit samples and records the dissolved oxygen, conductivity,              TRENCHES TO AT LEAST 100 MM ABOVE THE GROUND SURFACE TO REDUCE THE RISK OF UNDERCUTTING.
pH, turbidity and temperature of the stormwater.    For further details and specifications on the TPS 90-FLT please refer to Appendix B.                                                        3. NORMALLY, THEIR MAXIMUM HEIGHT SHOULD NOT EXCEED 600 MM ABOVE THE GULLY FLOOR. THE CENTRE SHOULD
                                                                                                                                                                                                   ACTING AS A SPILLWAY, BEING AT LEAST 150 MM LOWER THAN THE OUTER EDGES.
if the TPS 90-FLT unit Is not present a practical field test that approximates the required 50 NTU level Is to fill a clear plastic or glass 65mm diameter soft drink bottle with the           4. SPACE THE DAMS SO THE TOE OF THE UPSTREAM DAM IS LEVEL WITH THE SPILLWAY OF THE NEXT DOWNSTREAM
water and then hold It up to the light. If seeing clearly through the sample Is not possible, than the sample is probably above the 50 NTU level.                                                   DAM.

METHOD OF DEWATERING
The sediment basin can be dewatered as soon as the water quality criteria met (refer table below). A pump Is to be used to decant the basin with a floating Inlet to prevent the
settled sediments from being removed from the basin. The pumping must cease prior to the settled sediments being drawn into the Intake pipe, it Is essential that materials from
the sediment layer are not discharged In the pumping process.



 STORMWATER DISCHARGE QUALITY CRITERIA
                                                                                                                                                                                                                  1          1,
   ACCEPTABLE TSS              ACCEPTABLE PH            DISSOLVED 0=                                                                                                                                                                                           57/
                                                                                                                                                                                                                                                              7/7

   50mg/L                         6.5 - 8.5                   > 80%
                                                                                                                                                                                                                                    TOPSOIL STOCKPILE
                                                                                                                                                                                                  TOPSOIL STOCKPILE CONSTRUCTION NOTES
 SEDIMENT BASIN FLOCCULENT APPLICATION                                                                                                                                                            1. PLACE STOCKPILES MORE THAN 2 (PREFERABLY 5) METRES FROM EXISTING VEGETATION, CONCENTRATED
                                                                                                                                                                                                     WATER FLOW, ROADS AND HAZARD AREAS.
                                                                                      PRECAUTIONS & CONSTRAINTS                 MIN. READ. ON SITE                                                2. CONSTRUCTION ON THE CONTOUR AS LOW, FLAT, ELONGATED MOUNDS.
 AGENT         INDICATIVE DOSAGE              COMMENTS                                                                                                                                            3. WHERE THERE IS SUFFICIENT AREA TOPSOIL STOCKPILES SHALL BE LESS THAN 2 METRES IN HEIGHT.                               LL
                                                                                                                                                                                                  4. WHERE THEY ARE TO BE IN PLACE FOR MORE THAN 10 DAYS. STABILISE FOLLOWING THE APPROVED
  GYPSUM       32kg/100cub.m                  LITTLE PH CHANGE, SLIGHT INCREASE IN   NEEDS TO BE SPREAD EVENLY ACROSS POND.    260 kgm                                                               ESCP OR SWMP TO REDUCE THE C-FACIRCUROR TO LESS THAN 0.10.                                                             0
                                              SALINITY                               CAN CAUSE SCUM DEPOSITS IN EQUIPMENT.                                                                        5. CONSTRUCTION EARTH BANKS (STANDARD DRAWING 5-5) ON THE UPSLOPE SIDE TO DIVERT WATER AROUND
                                                                                                                                                                                                     STOCKPILES AND SEDIMENT FENCES (STANDARD DRAWING 6-8) 1 TO 2 METRES DOWNSLOPE.