Risks and opportunities for a Swiss hydropower company in a changing climate

Abstract. Anticipating and adapting to climate change impacts on water resources requires a detailed understanding of future hydroclimatic changes and of stakeholders' vulnerability to these changes. However, climate change impact studies are often conducted at a spatial scale that is too coarse to capture the specificity of individual catchments, and more importantly, the changes they focus on are not necessarily the changes most critical to stakeholders. While recent studies have combined hydrological and electricity market modeling, they tend to aggregate all climate impacts by focusing solely on reservoir profitability, and thereby provide limited insights into climate change adaptation. Here, we collaborated with Groupe E, a hydropower company operating several reservoirs in the Swiss pre-Alps and worked with them to produce hydroclimatic projections tailored to support their upcoming water concession negotiations. We started by identifying the vulnerabilities of their activities to climate change and then together chose streamflow and energy indices to characterize the associated risks. We provided Groupe E with figures showing the projected climate change impacts, which were refined over several meetings. The selected indices enabled us to simultaneously assess a variety of impacts induced by changes on i) the seasonal water volume distribution, ii) low flows, iii) high flows, and iv) energy demand. We were hence able to identify key opportunities (e.g., the future increase of reservoir inflow in winter, when electricity prices are historically high) and risks (e.g., the expected increase of consecutive days of low flows in summer and fall, which is likely to make it more difficult to meet residual flow requirements). This study highlights that the hydrological opportunities and risks associated with reservoir management in a changing climate depend on a range of factors beyond those covered by traditional impact studies. We also illustrate the importance of identifying stakeholder needs and using them to inform the production of climate impact projections. Our user-centered approach is transferable to other impact modeling studies, in the field of water resources and beyond.

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Risks and opportunities for a Swiss hydroelectricity company in a changing climate

Hydrology and Earth System Sciences ◽

10.5194/hess-24-3815-2020 ◽

2020 ◽

Vol 24 (7) ◽

pp. 3815-3833

Author(s):

Kirsti Hakala ◽

Nans Addor ◽

Thibault Gobbe ◽

Johann Ruffieux ◽

Jan Seibert

Keyword(s):

Climate Change ◽

Water Resources ◽

Electricity Market ◽

Electricity Demand ◽

Climate Impacts ◽

Water Volume ◽

Volume Distribution ◽

Impact Studies ◽

Changing Climate ◽

Low Flows

Abstract. Anticipating and adapting to climate change impacts on water resources requires a detailed understanding of future hydroclimatic changes and of stakeholders' vulnerability to these changes. However, impact studies are often conducted at a spatial scale that is too coarse to capture the specificity of individual catchments, and, importantly, the changes they focus on are not necessarily the changes most critical to stakeholders. While recent studies have combined hydrological and electricity market modeling, they tend to aggregate all climate impacts by focusing solely on reservoir profitability. Here, we collaborated with Groupe E, a hydroelectricity company operating several reservoirs in the Swiss pre-Alps, and we co-produced hydroclimatic projections tailored to support the upcoming negotiations of their water concession renewal. We started by identifying the vulnerabilities of their activities to climate change; together, we then selected streamflow and electricity demand indices to characterize the associated risks and opportunities. We provided Groupe E with figures showing the projected impacts, which were refined over several meetings. The selected indices enabled us to assess a variety of impacts induced by changes in (i) the seasonal water volume distribution, (ii) low flows, (iii) high flows, and (iv) electricity demand. This enabled us to identify key opportunities (e.g., the future increase in reservoir inflow in winter, when electricity prices have historically been high) and risks (e.g., the expected increase in consecutive days of low flows in summer and fall which is likely to make it more difficult to meet residual flow requirements). We highlight that the hydrological opportunities and risks associated with reservoir management in a changing climate depend on a range of factors beyond those covered by traditional impact studies. This stakeholder-centered approach, which relies on identifying stakeholder's needs and using them to inform the production and visualization of impact projections, is transferable to other climate impact studies, in the field of water resources and beyond.

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A Simplified Water Accounting Procedure to Assess Climate Change Impact on Water Resources for Agriculture across Different European River Basins

Water ◽

10.3390/w11101976 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1976 ◽

Cited By ~ 4

Author(s):

Johannes Hunink ◽

Gijs Simons ◽

Sara Suárez-Almiñana ◽

Abel Solera ◽

Joaquín Andreu ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

Expert Knowledge ◽

Climate Change Impacts ◽

River Basins ◽

Climate Impacts ◽

Green Water ◽

Local Context ◽

Water Fluxes ◽

Water Accounting

European agriculture and water policies require accurate information on climate change impacts on available water resources. Water accounting, that is a standardized documentation of data on water resources, is a useful tool to provide this information. Pan-European data on climate impacts do not recognize local anthropogenic interventions in the water cycle. Most European river basins have a specific toolset that is understood and used by local experts and stakeholders. However, these local tools are not versatile. Thus, there is a need for a common approach that can be understood by multi-fold users to quantify impact indicators based on local data and that can be used to synthesize information at the European level. Then, policies can be designed with the confidence that underlying data are backed-up by local context and expert knowledge. This work presents a simplified water accounting framework that allows for a standardized examination of climate impacts on water resource availability and use across multiple basins. The framework is applied to five different river basins across Europe. Several indicators are extracted that explicitly describe green water fluxes versus blue water fluxes and impacts on agriculture. The examples show that a simplified water accounting framework can be used to synthesize basin-level information on climate change impacts which can support policymaking on climate adaptation, water resources and agriculture.

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Quantifying the impact of climate change on water resources at the basin scale on five continents – a unified approach

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-7-7485-2010 ◽

2010 ◽

Vol 7 (5) ◽

pp. 7485-7519 ◽

Cited By ~ 18

Author(s):

M. C. Todd ◽

R. G. Taylor ◽

T. Osborne ◽

D. Kingston ◽

N. W. Arnell ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

River Flow ◽

Climate Change Impacts ◽

Global Scale ◽

Climate Impacts ◽

Catchment Scale ◽

Considerable Uncertainty ◽

Basin Scale ◽

The Impact

Abstract. This paper presents an overview of the methods and results of an assessment of climate change impacts on catchment scale water resources, conducted under the QUEST-GSI (Global Scale Impacts) programme. The project method involved running simulations of catchment-scale hydrology using a unified set of past and future climate scenarios, to enable a consistent analysis of the climate impacts around the globe. The results from individual basins are presented in other papers in 2010. Overall, the studies indicate that in most basins the models project substantial changes to river flow, beyond that observed in the historical record, but that in many cases there is considerable uncertainty in the magnitude and sign of the projected changes. The implications of this for adaptation activities are discussed.

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Amplified Impact of Climate Change on Fine-Sediment Delivery to a Subsiding Coast, Humboldt Bay, California

Estuaries and Coasts ◽

10.1007/s12237-021-00938-x ◽

2021 ◽

Author(s):

Jennifer A. Curtis ◽

Lorraine E. Flint ◽

Michelle A. Stern ◽

Jack Lewis ◽

Randy D. Klein

Keyword(s):

Climate Change ◽

Climate Change Impacts ◽

Baseline Period ◽

Climate Impacts ◽

Sediment Supply ◽

Balance Model ◽

Climate Projections ◽

Sediment Delivery ◽

Beneficial Reuse ◽

Coastal Margin

AbstractIn Humboldt Bay, tectonic subsidence exacerbates sea-level rise (SLR). To build surface elevations and to keep pace with SLR, the sediment demand created by subsidence and SLR must be balanced by an adequate sediment supply. This study used an ensemble of plausible future scenarios to predict potential climate change impacts on suspended-sediment discharge (Qss) from fluvial sources. Streamflow was simulated using a deterministic water-balance model, and Qss was computed using statistical sediment-transport models. Changes relative to a baseline period (1981–2010) were used to assess climate impacts. For local basins that discharge directly to the bay, the ensemble means projected increases in Qss of 27% for the mid-century (2040–2069) and 58% for the end-of-century (2070–2099). For the Eel River, a regional sediment source that discharges sediment-laden plumes to the coastal margin, the ensemble means projected increases in Qss of 53% for the mid-century and 99% for the end-of-century. Climate projections of increased precipitation and streamflow produced amplified increases in the regional sediment supply that may partially or wholly mitigate sediment demand caused by the combined effects of subsidence and SLR. This finding has important implications for coastal resiliency. Coastal regions with an increasing sediment supply may be more resilient to SLR. In a broader context, an increasing sediment supply from fluvial sources has global relevance for communities threatened by SLR that are increasingly building resiliency to SLR using sediment-based solutions that include regional sediment management, beneficial reuse strategies, and marsh restoration.

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