The contrast between the sandy loams around Mooroopna and the heavy clay flats near the Goulburn River is something you feel the moment you start digging. One site drains fast, the other holds water for weeks. That difference is exactly why our team runs field permeability tests using the Lefranc and Lugeon methods across Shepparton. We measure actual flow rates at the depth of interest rather than guessing from surface textures. For a housing development near Victoria Park Lake we found saturated conductivities ten times lower than the desktop study suggested. That kind of real data changes foundation decisions. Before that stage we often pair the test with a granulometry analysis to understand the particle size distribution driving those flow values, or with laboratory permeability for a controlled bench check on the same samples.
A single Lefranc test on a Shepparton clay site revealed permeability three orders of magnitude lower than assumed, saving a client from over-specified drainage.
Method and coverage
Regional considerations
The risk in Shepparton is not that the soil is uniformly tight — it is that permeability changes abruptly between layers. A three-metre lens of river sand hidden inside a clay sequence can drain a cut excavation overnight and destabilise the slope. Our field permeability test catches those lenses. We isolate each metre of the borehole with inflatable packers and run the test in discrete zones. If we hit a sand seam, the flow rate spikes and we see it immediately. That information lets your geotechnical engineer design dewatering or cutoff walls before the excavator arrives. Without it you gamble on assumed profiles, and in the Goulburn Valley that bet usually loses.
Standards that apply
AS 1726:2017 Geotechnical site investigations, AS 4678:2002 Earth retaining structures (referenced for drainage design), AS 1289.6.7.3 Standard practice for design and installation of groundwater monitoring wells, AS 1289 Standard test method for determining transmissivity and storage coefficient of low-permeability rocks
Complementary services
Lefranc permeability test (variable head)
Preferred for low‑permeability silts and clays common in the Shepparton urban area. We drill a borehole, seal a single packer above the test zone, and measure the rate of water level drop under a falling head. Results give a reliable k value for the specific stratum. Suitable for foundation drainage and settlement analysis.
Lugeon water pressure test
Used when the borehole intersects fractured claystone or cemented sand layers. We apply step‑increasing water pressure through a double‑packer system and record flow at each stage. The Lugeon value (litres per metre per minute) indicates whether the rock mass is tight or requires grouting. Standard on dam and deep excavation sites in Shepparton.
Typical parameters
Top questions
What is the difference between the Lefranc and Lugeon methods?
The Lefranc test uses a constant or falling head at low pressure and works best in soils (silts, clays, sands). The Lugeon test applies step‑increasing water pressure and is designed for rock or stiff claystone to detect fractures and estimate grout take. Both measure hydraulic conductivity but the Lugeon method gives information on joint opening under stress.
How much does a field permeability test cost in Shepparton?
A single test zone typically ranges between AU$950 and AU$1,430 depending on depth, access, and whether you need a Lefranc or Lugeon setup. The price includes mobilisation within Shepparton, on‑site testing, and a certified report. Additional zones or night work may adjust the rate.
Can you run the test on an existing borehole?
Yes, provided the borehole is reasonably clean and the casing (if present) is slotted or removed at the test interval. We inspect the hole with a down‑hole camera first to confirm the zone is intact. The packer seals against the natural wall or temporary casing. Results are valid for that specific depth.
How long does it take to get the results?
We deliver the permeability report within 48 hours of completing the test. The report includes raw pressure‑time data, calculated k values, and a graph of flow versus time. For urgent projects we can provide preliminary numbers by phone on the same day.