Bringing groundwater models to LIFE: a new way to assess water resource management options

Abstract

. Bringing groundwater models to LIFE: a new way to assess water resource management options. Hydrological Sciences Journal, 59 (3-4), 578-593.Abstract If management of water resources is to fully take into account the requirements of the environment, it will benefit from quantitative predictions of the ecological effects of river flow alterations. A significant relationship between flow reductions caused by groundwater abstraction and ecological conditions (as measured by relevant biotic indices) has been shown in streams in the midlands of England. In this article, we combine this relationship with hydrological indices derived from calibrated regional groundwater models to assess river reaches that are likely to be ecologically impacted by abstraction and might consequently be at risk of failing to meet EC Water Framework Directive standards. We demonstrate the application of this method within the framework of the Ecological Limits of Hydrologic Alteration (ELOHA) approach to making water resource decisions. We provide examples of how this approach can be used to assess the implications of different groundwater abstraction scenarios for river water bodies.Key words hydro-ecology; groundwater model; low flows; macro-invertebrates; abstraction Faire VIVRE les modèles hydrogéologiques-une nouvelle façon d'évaluer les options de gestion des ressources en eau Résumé Si la gestion des ressources en eau doit prendre pleinement en compte les besoins de l'environnement, elle bénéficiera des prévisions quantitatives des effets écologiques des altérations des écoulements en rivière. Une relation significative entre les réductions de débit causées par les prélèvements en eau souterraine et les conditions écologiques (telles que mesurées par des indices biotiques pertinents) a été démontrée pour des cours d'eau du centre de l'Angleterre. Dans cet article, nous combinons cette relation avec des indices hydrologiques issus de modèles hydrogéologiques régionaux, calés de manière à déterminer les tronçons de rivière susceptibles d'être impactés écologiquement par les prélèvements et qui, par conséquent, pourraient présenter le risque de ne pas répondre aux normes de la Directive cadre sur l'eau. Nous décrivons l'application de cette méthode dans le cadre de l'approche ELOHA (Ecological Limits Of Hydrologic Alteration-limites écologiques liées aux modifications hydrologiques) pour la prise de décision sur les ressources en eau. Nous fournissons des exemples sur la façon dont cette approche peut être utilisée pour évaluer les conséquences de différents scénarios de prélèvement d'eau souterraine sur les cours d'eau.

The changing role of ecohydrological science in guiding environmental flows

“…Hendriks et al (2014) reported that drainage and groundwater abstraction in sandy catchments in the Netherlands meant that low flows were reduced below the environmental flow criterion, whilst Kennen et al (2014) found that groundwater abstraction led to a 20% reduction in intolerant macro-invertebrates in New Jersey, USA, due to reduced river flow. Streetly et al (2014), working in the midlands of England, also found that flow reductions caused by The changing role of ecohydrological science in guiding environmental flowsgroundwater abstraction altered ecological conditions (as measured by relevant biotic indices).…”

“…The science of environmental flows has also benefited from closer links with other aspects of hydrological science. For example, groundwater modelling assists with understanding groundwater-fed ecosystems (Kennen et al 2014, Streetly et al 2014 including those in permeable sandy substrata (Hendriks et al 2014).…”

“…Wilding et al (2014) reported a strong relationship between flood flows and cottonwood abundance in Colorado, USA. In the UK, Streetly et al (2014) found a relationship between flow reductions caused by groundwater abstraction and ecological conditions. In Japan, Sui et al (2014) identified positive effects of natural flows and the negative effects of dams and weirs on the occurrence probability of most fish species.…”

How much groundwater can we pump and protect environmental flows through time? Presumptive standards for conjunctive management of aquifers and rivers

“…Ecological impacts occurred when the effect of abstraction exceeded 60% of Q75 flows regardless of water quality, habitat or seasonal effects. Streetly et al () combine this ecology–streamflow–groundwater pumping relationship with a calibrated regional groundwater model within an ELOHA framework to assess river reaches that are likely to be ecologically impacted by pumping and might consequently be at risk of failing to meet European Union Water Framework Directive standards.…”

A hydroecological model to assess the relative effects of groundwater abstraction and fine sediment pressures on riverine macro‐invertebrates

“…Although the adoption of simple “rules of thumb” by water managers to make decisions about environmental flows is a pragmatic approach in the short‐term, it represents a risk to the integrity and biodiversity of the world's riverine ecosystems (Arthington et al , ). The need for environment flow assessment methods that quantify links between ecology and water resource pressures to provide accurate local scale assessments is also pressing given the potentially large financial investments required to deliver precautionary environmental flows (Streetly et al, ).…”