Assessments now typically involve an “intense regional planning effort” which takes in the views of many stakeholders in order to maximise the environmental benefits to the watershed (USACE, 2008). Biodiversity offsets that are delivered in 20 or 30 years, for example, are intuitively less valuable to society than if those same biodiversity offsets were already fully functioning today (ICCM and IUCN, 2012). A biodiversity offset is typically defined by the level of ecological functionality that it will have when it reaches ecological maturity. Even if offsets prove to be successful in the future, there is a deficit of biodiversity in the landscape until the offset reaches ecological maturity which, for some ecosystem types, may take decades or more (Table 4.4). Temporary reductions in biodiversity can also increase the risk of unintended, irreversible biodiversity outcomes such as species extinction (Evans et al., Readily colonised by water beetles and dragonflies but fauna restricted to those with limited specialisations.