Relationships between environmental governance and water quality in a growing metropolitan area of the Pacific Northwest, USA

Abstract

Abstract. We investigate relationships between environmental governance and water quality in two adjacent growing metropolitan areas in the western US. While the Portland, Oregon and Vancouver, Washington metro areas share many common biophysical characteristics, they have different land development histories and water governance structures, providing a unique opportunity for examining how differences in governance might affect environmental quality. We conceptualize possible linkages in which water quality influences governance directly, using monitoring efforts as a metric, and indirectly by using the change in the sale price of single-family residential properties. Governance may then influence water quality directly through riparian restoration resulting from monitoring results and indirectly through land use policy. We investigate evidence to substantiate these linkages. Our results showed that changes in monitoring regimes and land development patterns differed in response to differences in growth management policy and environmental governance systems. Our results also showed similarities in environmental quality responses to varying governance systems. For example, we found that sales prices responded positively to improved water quality (e.g., increases in DO and reductions in bacteria counts) in both cities. Furthermore, riparian restoration efforts improved over time for both cities, indicating the positive effect of governance on this land-based resource that may result in improved water quality. However, as of yet, there were no substantial differences across study areas in water temperature over time, despite an expansion of these urban areas of more than 20 % over 24 years.The mechanisms by which water quality was maintained was similar in the sense that both cities benefited from riparian restoration, but different in the sense that Portland benefited indirectly from land use policy. A combination of long-term legacy effects of land development, and a relatively short history of riparian restoration in both the Portland and Vancouver regions, may have masked any subtle differences between study areas. An alternative explanation is that both cities exhibited combinations of positive indirect and direct water quality governance that resulted in maintenance of water quality in the face of increased urban growth. These findings suggest that a much longer-term water quality monitoring effort is needed to identify the effectiveness of alternative land development and water governance policies.

An alternative approach for socio-hydrology: case study research

“…The number of such models is slowly increasing. The issues modelled include flooding (Di Baldassarre et al, 2013, 2017Viglione et al, 2014;Grames et al, 2016;Yu et al, 2017;Girons Lopez et al, 2017;Barendrecht et al, 2017), water quality management (Chang et al, 2014), reservoir operation (Garcia, 2016); water supply (Srinivasan, 2015;Ali et al, 2017), groundwater abstraction (Noël and Cai, 2017), land degradation (Elshafei et al, 2015), subsistence farming (Pande and Savenije, 2016), the pendulum swing from water resources development and control to protection and restoration (van Emmerik et al, 2014;Elshafei et al, 2014;Chen et al, 2016;Roobavannan et al, 2017), and the collapse of civilizations (Kuil et al, 2016). Society is included in these different models in different ways.…”

Moving sociohydrology forward: a synthesis across studies

“…Several studies explored two-way coupling in specific regions: in Chennai, India (Srinivasan, 2015); Portland, Oregon, in the US (Chang et al, 2014); the Murrumbidgee in eastern Australia (Elshafei et al, 2014;Kandasamy et al, 2014;van Emmerik et al, 2014); the Toolibin catchment in western Australia (Elshafei et al, 2014); and Saskatchewan in Canada (Gober and Wheater, 2014). In the majority of these studies, the focus was on water scarcity generated primarily by human water demands.…”

“…Identifying the complete suite of interactions that constitute the pathways of influence between changes in water and changes in a social metric remains a significant challenge in these studies. For example, Chang et al (2014) explored the feedback between water quality and house prices, and land use policy and water quality. Although there is likely to be a relationship between home prices and land use policy as well, which would allow the feedback loop to be "closed", this relationship was not identified by the researchers, making it difficult to determine the complete set of relationships between land use, house prices and water quality.…”

“…The study finds that community norms and therefore how communities invest in infrastructure are shaped by water resource availability. Chang et al (2014) take an economic approach (hedonic value estimation) using property sales as a proxy to estimate how people value water quality improvements and consequently enforcement of water quality regulations.…”

Stakeholder Involvement

“…Total Maximum Daily Loads (TMDLs) are in place or in development for several water quality indicators [33]. LULC plays a major role in determining water quality indicator values and stream health within both urbanizing and agricultural catchments in the study area [34,35]. …”