The move could mean a four-month wait for the joint venture, which is managed by Canada-based Platinum Group Metals (TSX: PTM).
It had been granted an initial 30-year mining right in early February for the planned 45-year mine it believes could be one of the largest and lowest cash cost underground PGM mines globally.
Yesterday the company confirmed it had received a notice, to appeal the decision granting the mining right, on March 5.
"The notice was filed by a group of four individual appellants from a local community," PTM said.
The company said it believed all requirements specified under the Mineral and Petroleum Resources Development Act (MPRDA) were complied with and mines minister Gwede Mantashe's office had correctly issued the notice of granting the mining right.
"According to the MPRDA, an appeal can be considered by the minister for determination within a 130-day timeframe," it said.
It said it had completed "well-documented, extensive and meaningful consultations with recognised representatives in local communities, the DMRE and government".
It intended to continue consultations and said the mining right currently remained active.
"Our definitive feasibility study announced in September 2019, combined with a positive outlook for palladium, highlights that the local Waterberg communities and the broader Limpopo region in particular would benefit from the planned investment," PTM said.
The DFS had estimated Waterberg's initial cost at US$874 million, producing 420,000 4E ounces (palladium, platinum, gold and rhodium) a year at steady state.
It said in January the project value had more than doubled from the DFS post-tax NPV8 of $982 million to more than $1.98 billion using recent spot prices.
PTM has an effective 50.02% interest in Waterberg and manages the joint venture on behalf of Impala Platinum, Japan Oil, Gas and Metals National Corporation (JOGMEC), Hanwa and BEE partner Mnombo Wethu Consultants.
Its shares were worth about C$1.25 a year ago and spiked to $8 in December as it completed a couple of capital raisings.
It teed up another at-the-market offering in February, designed to raise up to US$50 million.
Its shares closed down 3.5% yesterday to C$4.46, valuing it about $329 million (US$260 million).