Landowners in the catchment had until Tuesday to register their expressions of interest in the upgraded scheme and to say how many hectares they wanted to irrigate. The interest shown by potential irrigators will determine which of the options goes ahead, if any.
''We're not being too hard and fast on the deadline but we do need people to register as soon as possible,'' Manuherikia Catchment Water Strategy Group chairman Allan Kane said.
The expressions of interest were still being collated and he hoped to have an indication soon on which option was favoured.
When the information packs were sent out last month, Mr Kane said it was ''crunch time'' for the irrigation upgrade plans.
The options include increasing the capacity of Falls Dam by raising it 6m or building a new dam directly downstream of Falls Dam, either 15m or 20m higher than the existing dam.
The number of hectares landowners want to irrigate will determine which option is adopted.
When they registered their interest, landowners were asked to give $50 per hectare to fund the next stage of the study.
The funds will be used for further geotechnical work on the proposed dam and to start the resource consent and land access process and establish a new company.
The estimated cost for work on the dam varies between present irrigators, who own the existing asset, and potential new irrigators. It ranges from $1875 to $4000 per ha of irrigated land.
