The approach used for this theme follows that outlined in the Approach report, with some changes required by the nature of inland waters, and the availability of associated data and information. Various challenges were found in applying the general approach, around both the timeframe of the assessment and the individual assessment components. For some components, it is clearly possible to assess changes in the past 5 years, whereas, for other components, changes to data, information and understanding in the past 5 years mean that we may have a different understanding of that component now. Overall, however, the approach used here compares well with that used in the 2011 State of the Environment (SoE) report.
The 4 high-level pressures from 2011 (climate, development, land use and management, and pests and invasive species) are all considered here. In all of these, there have been changes in both the pressure and the information available in the past 5 years.
A new section on groundwater has been added to state and trends reporting, reflecting the dramatic change in national availability of consistent groundwater data and information since 2011, as well as increased national focus on groundwater in aquatic ecological systems. Assessment of the state and trends of water levels and flows also benefits greatly from increased access to national, collated information sources. Water quality, conversely, suffers from a lack of a large and comprehensive national analysis, such as that undertaken as a one-off for 2011. The state and condition of aquatic ecology use a somewhat comparable approach to 2011, albeit, again, without being able to draw on a one-off SoE-focused analysis.
The assessment for effectiveness of management focuses more on water resource development than in 2011, where effects of inland water management were assessed as part of both flows and levels, and with regard to management effectiveness. This more clearly separates the ‘state’ of water, as directly influenced by the ‘pressures’, from the state of water affected by management activities.
The approaches used for resilience and risks are largely comparable with those used in 2011. Consideration of resilience has been somewhat extended to consider the evidence that may exist on, and the characteristics that may be evident in, the resilient behaviour of aquatic ecosystems, because these ecosystems have responded to the highs and lows of recent years and decades.