Farmers in north-west New South Wales say they are outraged at a fine handed to a coal company for unlawfully taking water, saying it amounts to a mere "slap on the wrist". 

Whitehaven Coal has been fined $200,000 in the Land and Environment Court for unlawfully taking 1,000 megalitres of water at its Maules Creek mine between 2016 and 2019.

The company pleaded guilty to the charge earlier this year.

The market value of the water at the time from the Lower Namoi Regulated Water Source could have amounted to as much as $390,000.

Maules Creek resident Ros Druce said local landholders were disappointed at the final amount, which was less than 20 per cent of the maximum penalty.

"I don't think that's going to deter them one little bit from any further offences," she said.

In her judgement, Justice Nicola Pain gave the company a 20 per cent discount for pleading guilty, and ruled the company had shown remorse, having entered into an enforceable undertaking.

"The detail and onerousness of the undertaking is part of the punishment and should operate to reduce the penalty," Justice Pain said.

Ms Druce said she disagreed that the undertaking was a sign of remorse.

"If it's an enforceable undertaking, you have to do it," she said.

Environmental consequences

The court heard evidence from hydrologist Doug Anderson that the unlawful take reduced the downstream flow in the nearby Back Creek, and compromised the recharge of riparian groundwater in the area.

He argued the timing of the offence coincided with "the worst drought in living memory" and that the water had significantly more environmental value than normal.

But Justice Pain said she found it difficult to assess the impact of the take, because the precise timing was unclear.

The judgement also revealed that a joint venture of Whitehaven earned more than $285,000 from two temporary water trades in June 2017 and April 2018, which the prosecutor argued was a direct result of the theft.

But Justice Pain ruled there was "no factual basis" to support that claim.

In a statement to the ASX, Whitehaven Coal said it had previously acknowledged shortcomings in some of its systems.

"[Whitehaven] has made significant progress to implement measures to improve clean water management at the mine," the statement read.