Legacy effects of historical gold mining on floodplains of an Australian river.

The gold rush at the end of the nineteenth century in south-eastern Australia resulted in the mobilization and re-deposition of vast quantities of tailings that modified the geomorphology of the associated river valleys. Previous studies of contamination risk in these systems have either been performed directly on mine wastes (e.g., battery sand) or at locations close to historical mine sites but have largely ignored the extensive area of riverine alluvial deposits extending downstream from gold mining locations. Here we studied the distribution of contaminant metal(loids) in the Loddon River catchment, one of the most intensively mined areas of the historical gold-rush period in Australia (1851-1914). Floodplain alluvium along the Loddon River was sampled to capture differences in metal and metalloid concentrations between the anthropogenic floodplain deposits and the underlying original floodplain. Elevated levels of arsenic up to 300 mg-As/kg were identified within the anthropogenic alluvial sediment, well above sediment guidelines (ISQG-high trigger value of 70 ppm) and substantially higher than in the pre-mining alluvium. Maximum arsenic concentrations were found at depth within the anthropogenic alluvium (plume-like), close to the contact with the original floodplain. The results obtained here indicate that arsenic may pose a significantly higher risk within this river catchment than previously assessed through analysis of surface floodplain soils. The risks of this submerged arsenic plume will require further investigation of its chemical form (speciation) to determine its mobility and potential bioavailability. Our work shows the long-lasting impact of historical gold mining on riverine landscapes.

Ecological water, a new focus of China's water management.

Water set aside for environmental purposes is now the fastest-growing category of water use in China. Since 2000 this 'ecological water' (EcoW) has grown to make up 5 % of the total water allocation (around 30 billion m3 of water). This paper provides the first substantial review of the history, definition, and policy rationale for EcoW in China, and allows us to compare the Chinese program with elsewhere. As in most countries, the growth in EcoW is a response to the over-allocation of water, and a recognition of the broader values of aquatic systems. In contrast to other countries, most EcoW is still allocated to support human values more than natural values. The earliest, and most celebrated EcoW projects, were directed at reducing dust pollution from arid zone rivers affecting northern China. In other countries, most environmental water is clawed back from other users in a catchment (usually irrigators) and is then delivered as a quasi-natural flow regime from a dam. These sorts of environmental flows from dams do occur in China, represented by the EcoW diversion in the Heihe River Basin and the Yellow River Basin. By contrast, the largest EcoW programs do not replace existing uses. Instead, they augment flows through large interbasin transfers. The largest and fastest-growing EcoW program in China is on the North China Plain (NCP) based on excess water available from the South-North Water Transfer project. To illustrate the complexity of EcoW projects in China, we describe in more detail two case studies, the well-established arid-zone Heihe EcoW program and the newer Jin-Jin-Ji EcoW program on the NCP. Overall, ecological water allocation in China reflects a major development in water management in that country and a growing shift toward more holistic water management.

Wood stock in neotropical streams: Quantifying and comparing instream wood among biomes and regions.

Instream wood plays important chemical, physical and ecological functions in aquatic systems, benefiting biota directly and indirectly. However, human activities along river corridors have disrupted wood recruitment and retention, usually leading to reductions in the amount of instream wood. In the tropics, where wood is believed to be more transient, the expansion of agriculture and infrastructure might be reducing instream wood stock even more than in the better studied temperate streams. However, research is needed to augment the small amount of information about wood in different biomes and ecosystems of neotropical streams. Here we present the first extensive assessment of instream wood loads and size distributions in streams of the wet-tropical Amazon and semi-humid-tropical Cerrado (the Brazilian savanna). We also compare neotropical wood stocks with those in temperate streams, first comparing against data from the literature, and then from a comparable dataset from temperate biomes in the USA. Contrary to our expectations, Amazon and Cerrado streams carried similar wood loads, which were lower than the world literature average, but similar to those found in comparable temperate forest and savanna streams in the USA. Our results indicate that the field survey methods and the wood metric adopted are highly important when comparing different datasets. But when properly compared, we found that most of the wood in temperate streams is made-up of a small number of large pieces, whereas wood in neotropical streams is made up of a larger number of small pieces that produce similar total volumes. The character of wood volumes among biomes is linked more to the delivery, transport and decomposition mechanisms than to the total number of pieces. Future studies should further investigate the potential instream wood drivers in neotropical catchments in order to better understand the differences and similarities here detected between biomes and climatic regions.

Local scale interventions dominate over catchment scale controls to accelerate the recovery of a degraded stream.

A premise of stream restoration theory and practice is that it is often futile to attempt to restore a stream at the reach scale (101-103 metres) until catchment scale problems have been addressed. This study considers reach scale restoration actions undertaken in Bryan Creek, a sand bed river in south east Australia impacted by a sediment pulse, after catchment sediment sources have been addressed. Local scale interventions, which were in-stream sand extraction, fencing to exclude stock and riparian revegetation, were evaluated by quantifying cross-section and thalweg variability, mapping in-stream and riparian vegetation and by classifying the morphology that emerged following each intervention. Following intervention channel reaches moved to one of three distinct states: simple clay bed, eroding reaches dominated by Juncus acutus, and reaches with deep pools and Phragmites australis. Boundaries between the intervention reaches were sharp, suggesting local scale interventions dominate over catchment scale processes. The magnitude and spread of variability metrics were similar between all reaches and differences in variability bore no relation to intervention type, despite the stark difference in post-intervention morphology. These findings suggest that cross-section and thalweg variability metrics are an inadequate proxy for the effectiveness of local scale interventions in accelerating the recovery of sand bed reaches from a bedload pulse. The most important implications for river managers is that local scale interventions can lead to substantial and rapid improvements in condition, and the change in condition of these reaches is almost independent of other reaches. In this case, the key to the pattern of reach scale geomorphic recovery is excluding stock from waterways so that a specific macrophyte can establish, trap sediment and develop pools.

'Sub-Prime' Water, Low-Security Entitlements and Policy Challenges in Over-Allocated River Basins: the Case of the Murray-Darling Basin.

Environmental policy is often implemented using market instruments. In some cases, including carbon taxing, the links between financial products and the environmental objectives, are transparent. In other cases, including water markets, the links are less transparent. In Australia's Murray-Darling Basin (MDB), financial water products are known as 'entitlements', and are similar to traditional financial products, such as shares. The Australian water market includes 'Low Security' entitlements, which are similar to 'sub-prime' mortgage bonds because they are unlikely to yield an amount equal to their financial worth. Nearly half the water purchased under the Murray-Darling Basin Plan for environmental purposes is 'Low Security'. We suggest that the current portfolio of water held by the Australian Government for environmental purposes reflects the mortgage market in the lead-up to the global financial crisis. Banks assumed that the future value of the mortgage market would reflect past trends. Similarly, it is assumed that the future value of water products will reflect past trends, without considering climate change. Historic records of allocations to 'Low Security' entitlements in the MDB suggest that, in the context of climate change, the Basin Plan water portfolio may fall short of the target annual average yield of 2075 GL by 511 GL. We recommend adopting finance sector methods including 'hedging' 'Low Security' entitlements by purchasing an additional 322-2755 GL of 'Low Security', or 160-511 GL of 'High Security' entitlements. Securing reliable environmental water is a global problem. Finance economics present opportunities for increasing the reliability of environmental flows.

Using voluntary agreements to exclude stock from waterways: An evaluation of project success and persistence.

Agriculture is one of the major drivers of ecological degradation in river basins. Excluding stock (cows and sheep) from grazing riverbanks and accessing rivers is one of the most common river restoration activities. To be effective, stock exclusion must be maintained indefinitely. In Australia, and elsewhere, stock exclusion projects are most commonly implemented by establishing voluntary agreements between landholders and government agencies. This study examined the extent to which landholders in 3 catchment management authority (CMA) regions in southeast Australia maintain stock exclusion from waterways, whether vegetation on riverbanks recovered, and the effectiveness of assessment methods. It was found that nearly half of landholders continue to graze stock on the riverbank. There has been some success with improving the condition of riparian vegetation. Sites with full stock exclusion contain the pre-European abundance of juvenile trees, and sites with continued grazing contain significantly lower abundance of juvenile trees. Establishing the effectiveness of management was made more difficult by the inconsistent methods used by the different CMAs. Stock exclusion projects implemented with voluntary agreements have the potential to succeed if oversight is improved between government agencies and CMAs and between CMAs and landholders. Projects will be easier to assess if regional authorities use consistent methods of assessment. Voluntary agreements are only suitable for environmental management if projects are monitored, maintained, and assessed appropriately. Integr Environ Assess Manag 2019;15:237-247. © 2018 SETAC.

The Case for "Environment in All Policies": Lessons from the "Health in All Policies" Approach in Public Health.

BACKGROUND: Both public health, and the health of the natural environment, are affected by policy decisions made across portfolios as diverse as finance, planning, transport, housing, education, and agriculture. A response to the interdependent character of public health has been the "health in all policies" (HiAP) approach. OBJECTIVES: With reference to parallels between health and environment, this paper argues that lessons from HiAP are useful for creating a new integrated environmental management approach termed "environment in all polices" (EiAP). DISCUSSION: This paper covers the theoretical foundations of HiAP, which is based on an understanding that health is strongly socially determined. The paper then highlights how lessons learned from HiAP's implementation in Finland, California, and South Australia might be applied to EiAP. It is too early to learn from evaluations of HiAP, but it is apparent that there is no single tool kit for its application. The properties that are likely to be necessary for an effective EiAP approach include a jurisdiction-specific approach, ongoing and strong leadership from a central agency, independent analysis, and a champion. We then apply these properties to Victoria (Australia) to demonstrate how EiAP might work. CONCLUSIONS: We encourage further exploration of the feasibility of EiAP as an approach that could make explicit the sometimes surprising environmental implications of a whole range of strategic policies. Citation: Browne GR, Rutherfurd ID. 2017. The case for "environment in all policies": lessons from the "health in all policies" approach in public health. Environ Health Perspect 125:149-154; http://dx.doi.org/10.1289/EHP294.