Regulator guidance and legislation relevant to pit lakes

Open cut mining that develops pit lakes is common internationally, but regulatory guidance specific for pit lake formation and development is sparse in the international context. Instead, approaches toward pit lake development have generally been made by considering every mine site as unique. As a result, current international practice is that development of pit lakes should, and are generally managed on a case-by-case basis. There are a wide range of broad but non-specific forms of regulatory direction and processes such as water quality guidelines to allow for an initial decision-making strategy on whether it is desirable for pit lakes to form and as to what potential end uses may be. However, most of the regulatory guidance focuses heavily on risk as the sole pit lake end point at mine closure. Development of clear social or environmental end use goals in pit lake uses may provide either benefit or to even offset some of the risk.

Once an end use goal is established and comfortably articulated as fitting with broader company sustainabiltiy strategies it will assist in the development of general conceptual plans for a mine pit lake at lease relinquishment. It will also serve to inform regulators of a well-developed concept for going beyond current broad guidelines for it lake formation and management to better achieve corporate goals of sustainability and social licence-to-mine.

The timescale for the evolution of lakes as end uses may be in the order of hundreds of years. In order to be successful, presenting a well-developed pit void closure plan to regulators and stakeholders hould ideally be the conclusion of many years of a well-developed strategy of testing, refinement and stakeholder engagement of an end use development proposal.