Whitehaven CEO Paul Flynn said the scheduled Narrabri mine longwall move from LW108 to LW109 also curtailed quarterly production.
"This quarter Narrabri's scheduled longwall change out and chock leg cylinder replacement were completed on time, on budget and without injury," he said.
"The December quarter production results reflect the impact of the previously reported labour shortages and dust events at our largest mine, Maules Creek.
"Whitehaven is investing in the people, processes and equipment needed to overcome short-term challenges, to deliver improved operational performance and to execute on its growth strategy."
Whitehaven continues to work with relevant NSW authorities to access and optimise Whitehaven's water sources in the region.
During 2019, Whitehaven took a number of steps to enhance its security of water supply, including acquiring property near Maules Creek with productive groundwater resources; transferring various water access licences across the Whitehaven Group; and purchasing temporary water entitlements.
It has also hauled water between supply points and mines; increased the use of dust suppressants; and implemented enhanced water efficiency measures in coal handling and prep plants.
"Further work on ensuring continuity of water supply for the medium and long term is ongoing, including obtaining regulatory approvals, and we do not currently expect any interruption to FY2020 production in connection with water supply," the company said.
Morgans analyst Tom Sartor said it looked like most of Whitehaven's issues were behind it.
"Key today was feedback that actual weather disruption and Maules equipment utilisation is tracking better than the assumptions built into FY20 guidance," he said.
"We trim our revenue forecasts based on softer 2Q thermal price realisation, although this is also set to revert back toward normality in the 3Q."
Morgans retained an add recommendation and dropped its price target from A$3.67 to $3.46.
"Whitehaven looks far too cheap trading at a circa 25% discount to fair value, with the start of the operational recovery and stable thermal coal pricing offering comfort," Sartor said.
"We think Whitehaven is an accumulate for value investors here, but we think that momentum traders may remain sidelined by tepid seaborne coal/LNG pricing, and by ongoing anti-coal sentiment."
Whitehaven shares were unchanged on Thursday at $2.59. The stock hit a 52-week low of $2.49 just before Christmas.