Groundwater‐dependent ecosystems in Oregon: an assessment of their distribution and associated threats

Abstract

Effective protection and management of groundwater‐dependent ecosystems (GDEs) are hindered by inadequate information on their locations and the condition of associated groundwater supplies. We addressed this knowledge gap by developing a methodology that uses existing datasets to locate GDEs (including groundwater‐dependent springs, lakes, rivers, wetlands, and species) and assess threats to groundwater quantity and quality. Here we report on the application of this method across the US state of Oregon. Nearly 40% of watersheds in Oregon contain two or more types of GDEs – termed “GDE clusters” – indicating the widespread importance of groundwater to ecosystems. Documented problems may underestimate the threat to ecosystems from altered groundwater supply or quality. Although documented occurrences of water‐table declines are limited, high densities of permitted wells (for irrigation or other commercial purposes) pose a threat to groundwater availability in 18% of GDE clusters. Furthermore, although only 5% of GDE clusters have known groundwater contamination, our assessment indicates that 30% of GDE clusters are threatened with groundwater contamination by nitrates, 30% by industrial chemicals, and 70% by pesticides. This initial assessment of GDEs and threats to their groundwater supply highlights the ecological importance of groundwater and the need to incorporate protection of GDEs in water management policy.

Hydro-ecology of groundwater-dependent ecosystems: applying basic science to groundwater management

“…The last decade has seen significant progress in many of these tasks. There are various methods for identifying and mapping GDEs and understanding their threats (Brown et al 2011, Australian Bureau of Meteorology 2012, and current groundwater assessment frameworks provide broad guidance on identifying GDEs and describing their groundwater requirements (Schutten et al 2011, Sinclair Knight Merz 2011, UK TAG 2012.…”

“…Groundwater-dependent ecosystems (GDEs) include wetlands, lakes, rivers, springs, estuaries and off-shore marine environments, subterranean ecosystems and some terrestrial vegetation such as phreatophytes, as well as the many species that rely on groundwater to meet part or all of their water requirements (Eamus and Froend 2006, Brown et al 2011, Sinclair Knight Merz 2011. In these ecosystems, groundwater may provide water with physical and chemical characteristics that differ from surface water supplies, and this has important consequences for their structure and function.…”

Applying a statewide geospatial leaching tool for assessing soil vulnerability ratings for agrochemicals across the contiguous United States

“…There are some straightforward tools for assessing the leaching potential of pesticides by different input parameters and screening algorithms. Screening Concentration In GROund Water (SCI-GROW; Pereira et al, 2014), Windows Pesticide Screening Tool (WIN-PST; Brown et al, 2011), and statistical regression models of regional and national scales (Stackelberg et al, 2012) are the tools offered at the federal level from the US Environmental Protection Agency (USEPA), Department of Agriculture (USDA), and Geological Survey (USGS), respectively. Attenuation factor (AF), implemented at the State of Hawaii in the US, is a state-level tool used for pesticide evaluation procedure such as pesticide registration and certification (Ki and Ray, 2015;Stenemo et al, 2007).…”

A Review of Advances in the Identification and Characterization of Groundwater Dependent Ecosystems Using Geospatial Technologies

“…These interpolation methods can also provide new surfaces from data that was acquired using remote sensing technologies, such as calculating slope and aspect from a topographic map that was produced by photogrammetric techniques using aerial images [126]. Studies that benefit from this integration have developed a number of indexes that compile major variables that influence groundwater dependence [127,128].…”