Docstoc

SIPHON TRIAL

Document Sample
SIPHON TRIAL Powered By Docstoc
					CATCHMENT DEMONSTRATION INITIATIVE – PROJECT SHEET



                                          SIPHON TRIAL
                                      ON HILLSIDE SEEP (OB5)

                                          This project demonstrates the use of a siphon
        LOCATION                          technique to recover an area of saline land caused by
                                          a hillside seep. This should reduce further salinity risk
                                          of arable land below. The hillside seep is caused by a
                                          near-surface rock outcrop intercepting sub-surface
                                          water flow from deep sandy duplex soils from the
                                          north east and from the deep gradational sands to the
                                          north.
                                          A backhoe pit dug above the seep showed the water
                                          table to be near the surface and highly saline. The
                                          lower slopes of the seep have relatively fresh water.
                                          This indicates that high groundwater movement
                                          through the soils of the gradational sands is also
                                          contributing separately to this site (i.e. below the
                                          bedrock). It is expected that these soils also
                                          contribute to the seep above where groundwater is
                                          saline. Continuous discharge from the siphon will be
     “IF SIPHONING IS                     through a pipe and into the O’Brien Creek.
SUCCESSFUL THEN THE NEED
                                          In February 2006 a 21 day trial of the proposed
  FOR EXPENSIVE POWER,                    groundwater siphon at the site. The flow rate over the
                                          21 days of the trial was 0.1 litres/second using 19 mm
PUMPING EQUIPMENT AND
                                          polyethylene pipe. Prior to the trial the groundwater
ASSOCIATED MAINTENANCE                    level was 0.775 m above ground level, at the
IS NOT AN ISSUE. THERE MAY                completion of the trial it was 0.11 m below ground
                                          level. 25mm pipe has now been installed and flow rate
 EVEN BE POTENTIAL USES                   is 0.2litres/second.
      FOR THE WATER”




       FURTHER INFORMATION
  Contact: Glenice Batchelor
  Phone: +61 8 9045 4006
  Email: clc@kellerberrin.wa.gov.au
  Website: www.kellerberrin.wa.gov.au     Land owner Colin Wilkins and CDI Project Manager Glenice Batchelor monitoring
                                          siphon yield at project site OB5 during the 21 day testing phase.
                                                 PROJECT SITE INFORMATION

                                                                                        2006


Landholders Involved                 •      Colin and Betty Wilkins and family
Location                             The upper slopes of the O’Brien Catchment.
Threat                               A hill-side seep east of Mission Road affects 12.5 ha
                                     of agricultural land and threatens a further 5 ha. A
                                     200m section of the road is also affected including a
                                     culvert requiring work.
Previous Activities                  Previous management including WISALT banks to
                                     control surface water has not reduced the seep
                                     significantly.
Salinity Risk                        Existing and further risk to land and Shire road.
Groundwater Quality                  2250mS/m
Groundwater pH                       5.41
Site Investigations & Partnerships   1.     Paddock scale geophysical survey using
                                            contractors and interpretation was completed
                                            by CRC LEME/Curtin and Technical Advisory
                                            Group.
                                     2.     Test drilling for siphon and siphon installation
                                            supervised by Department of Agriculture and
                                            Food WA. Groundwater yield testing was
                                            undertaken.
                                     3.     Surface water management structures assessed
                                            with assistance from Department of Agriculture
                                            and Food WA.
Regulatory Issues                    A Notice of Intent to Drain or Pump (NOI) was
                                     submitted and was not objected to. Permission to test
                                     siphon for 21 days was required.
Critical Information                 •      Slope gradient from site to discharge outlet.
                                     •      Geophysics was used to locate the drilling
                                            program.
                                     •      Drilling of monitoring holes confirmed that the
                                            saline area is groundwater derived (there is
                                            near-surface bedrock) and could be siphoned.
                                     •      The water quality from yield testing meant a
                                            detention basin was not required.
Costs                                Pipes, fittings, installation - $1500, Geophysics -
                                     $5000, Drilling program - $5000. No ongoing running
                                     costs. Labour not included in these costs.
                                      NB: A significant amount of Technical Advisory Group
                                     and Partnership time is not accounted for in these
                                     costs.
Expected Benefits of Project         •      Recovery of productive land and reduction in
                                            further salinity risk.
                                     •      Monitoring of bores will indicate impact of the
                                            siphoning. It is anticipated that the water
                                            quality will improve over time. This will be
                                            monitored regularly.

				
DOCUMENT INFO
Shared By:
Categories:
Tags: SIPHON, TRIAL
Stats:
views:4
posted:4/4/2010
language:English
pages:2
Description: SIPHON TRIAL