Department senior development officer Tony Portman said the initial scoping study conducted in 2005-06 looked at the potential to capture sufficient surface water run-off to support intensive agricultural production.

"The study area incorporated land from North Bannister to Lake Muir, south-east of Manjimup," he said.

"It was based on broad-scale modelling and on a land-soil capability assessment that found that there was some potential to develop large reliable water supplies to support intensive agriculture.

"The areas around Boddington, Boyup Brook, Bridgetown and Manjimup appeared to have the greatest potential."

Mr Portman said the modelling estimated all the fresh run-off generated in the catchment, but did not take into account evaporation loss, existing storage, flow leakage or environmental flow requirements.

"The results will be used to prioritise catchments with the greatest development potential, target investment in further research and determine if further work is needed," he said.

"If large water supplies are to be developed, extensive investigation and testing of specific sites will also be necessary."

Mr Portman said potential perennial crops, such as citrus, Chinese red date and green tea had been selected for further investigation based on climatic data, crop requirements and future market potential.

"To put it in perspective, a 10ha fruit orchard requires, on average, 57-75 megalitres annually," he said.

"Of catchments, identified on private land, by the study, 152 have annual flow of 75-100 ML, 203 could yield 100-200 ML and three have more than 400 ML of annual flow."

Workshops for interested landowners will be held in October and November to provide more information on the potential to capture freshwater to support new enterprises.

* For more information or to register for a workshop, contact Tony Portman on (08) 9780 6100 or 0427 773 168 or Lauren Johnston 0437 281 491.