The investigations are part of Operation Watershed, West Sussex County Council’s £8.25m initiative to combat problems caused by adverse weather conditions.
The aim is to help residents in Lancing who are still experiencing problems with drainage because of high ground water levels.
Many living near the A27 said their Christmas and New Year were ruined by flooding, which prevented them from using toilets, showering and washing up.
Pieter Montyn, county cabinet member, said: “We are determined to solve the surface water problems in Lancing Manor for the residents affected there.
“Unfortunately, floods happen and one in six properties are at risk of flooding, so people must be prepared.
“By preparing now, you can limit the distress and damage which may be caused further down the line.”
Water is being pumped from the Lancing Brooks into the River Adur at high tide.The outfall, near the Dogs Trust rehoming centre in Brighton Road, Shoreham, drains a large ditch network around Shoreham Airport and north Lancing.
West Sussex Fire and Rescue is using a high velocity pump to help drain the ditch network when the tide is in.
The aim of the trial pumping exercise is to investigate how the drainage of the ditch network could be improved during high tides, when the outfall would normally be tide locked.
While this took place last week, the footpath between Adur Recreation Ground and Brighton Road was temporarily closed.
The Environment Agency replaced the Lancing Brooks outfall two years ago and greatly increased its capacity.
Andrew Gilham, the agency’s flood and coastal risk manager, said: “We support this trial to help investigate the suggestions that pumping may help those residents suffering the devastating effects of flooding.
“We have invested significantly in improving the outfall structure in recent years and it continues to operate effectively.”
In addition to the pumping exercise, the county council has undertaken a programme of vegetation clearance from the ditch network in the area around Shoreham Airport.
These maintenance works have improved the flow of water through the ditches.
The current pumping exercise is being carried out by the county council, in conjunction with Southern Water, the Environment Agency, West Sussex Fire and Rescue and Worthing and Adur councils.
For further details about Operation Watershed, visit www.westsussex.gov.uk/watershed.
For more information about how to prepare for floods, visit www.westsussex.gov.uk and search under “flooding”.