Accounting for ecosystem services in water quality standards compliance.

Abstract

O the past decade, legislation to improve water quality across Europe and the United States has focused on returning surface waters to “reference” conditions, defined as a state in the past or present, corresponding with minimal anthropogenic pressures (i.e., without the effects of industrialization, urbanization or intensive agriculture and, with only minor modification of physico-chemistry, hydromorphology and biology). Much of this legislation is designed to address eutrophication, nuisance algal growth and water-body hypoxia, which are a pervasive source of water quality impairment. Eutrophication has profound implications for environmental and human health, and water security. In the E.U., the Water Framework Directive (WFD, 2000), now mandates that all surface waters (except those subject to specific derogations) must achieve “Good Ecological Status” (GES) by 2015. Good Ecological Status is defined as deviating only slightly from “undisturbed” reference conditions, based on an integrated assessment of water-body ecological condition, including biological, hydromorphological and physicochemical quality elements. Here, we present data which show that large areas of Europe are currently failing to achieve GES (Figure 1). We argue that reference conditions, reflecting an undisturbed nearpristine state, are unlikely to be achievable over WFD time scales, for many watersheds which provide the vital ecosystem services, such as food production and wastewater disposal, and water purification and treatment. These ecosystem services support communities and the economic activity upon which society depends. We propose that accounting for watershed ecosystem services, along with a directional approach based on “gap closure” between present conditions and desired waterquality “reference” end points, offers a way forward for continued improvement in the quality and ecology of surface waters. In 2012, 12 years after the WFD became law, only one river basin district within the EU, in remote and sparsely populated subarctic Finland, achieved GES in more than 90% of its water bodies (Figure 1). Across large areas of the lowlands of central and northwestern Europe, which support large urban centers and productive agricultural regions, less than 30% of water bodies are achieving GES. However, the watersheds of many of these “failing” rivers provide the ecosystem services which underpin European food security and economic activity, and it is unrealistic to expect that these can be returned to nearpristine reference conditions by 2015. For example, rivers in lowland UK drain watersheds where 70% of the land area is used for agriculture, achieving over 60% self-sufficiency in UK food production. While efforts continue apace to reduce water quality impairment from farming and urban/wastewater sources, and major successes have been achieved in improving water quality over the last few decades, only 25% of all English water bodies currently achieve Good Ecological Status or Potential (the standard for water bodies that are artificial or heavily modified). Of these GES failures, 31% were attributed to agricultural and rural land management, 32% to the water industry (wastewater treatment plants); and 14% from other urban sources. Phosphorus (P) was the largest single contributor to GES failures (accounting for c. 60% of agricultural/rural and c. 50% of water industry failures). Indeed, the changes required to achieve GES, as currently defined, could have profound implications for food security, economic activity and livelihoods. It is estimated that a 50% reduction in P from agriculture would be needed across England, with implications for the intensity and scale of agricultural production at a time when food demand is rising to meet the projected growth in population of c. 20% by 2035. Moreover, given the legacy of P stored within these watersheds, it will likely take several decades to achieve these water-quality standards. As the 2015 WFD deadline approaches, “opting out” by derogating vast areas from the requirement to achieve GES by 2015, or delaying compliance until 2021 or 2027, seem to be the only options for many EU states. This risks undermining the whole WFD process, with further challenges ahead for currently failing watersheds in meeting more restrictive standards for the 2021 or 2027 compliance rounds.