The objectives of this climate risk assessment for the Li River in China is to assess current flood risk and future flood risk in the Li river basin in China. With an average of 1800 mm annual total rainfall, floods are severe and frequent in the region. Additionally to rainfall, severe floods in are often related to discharges from upstream reservoirs

Given the fact that this area is data scarce, global datasets with climatic data (ERA5-Land), soil parameters (HiHydroSoil) and land cover (Copernicus) were used to feed a hydrological HEC-HMS model to calculate the discharge for the extreme event of June 2020. Based on measured water levels and discharge, it was possible to develop rating curves and with these rating curves, it was possible to estimate water levels in the river for current (validation) and future conditions. This analysis served as input for the full climate risk assessment,  in which possible interventions were proposed to reduce flood risk in the future.

The goal of the Asian Development Bank project ‘Renewable Energy for Climate Resilience’ in Bhutan is to diversify Bhutan’s energy portfolio. Bhutan’s power sector almost exclusively relies on hydropower generation. Hydropower, however, is vulnerable to climate change and natural disasters caused by climate change. The first deployment of non-hydro renewables at utility scale in Bhutan will be the first step to diversify the power generation portfolio, increase the resilience against severe weather events such as droughts, and complement the hydropower generation profile during the dry season. Other renewable energy resources such as solar photovoltaic (PV) and wind can complement hydropower in forming a more diversified electricity generation portfolio, which is, in healthy mix, resilient to changes in seasonal weather patterns and weather extremes that can adversely affect power supply.

Within this project ADB develops two solar and one wind plant. FutureWater has undertaken a Climate Risk and Adaptation assessment (CRA) for these power plants, with a two-fold objective:

  1. Validate the underlying rationale for diversification of Bhutan’s energy generation portfolio. The rationale is that more unreliable flows under climate change adversely affect the hydropower generation, in particular in the low flow season outside the monsoon season. This are the seasons with high potential for solar and wind energy, under the current climate conditions. The diversification of Bhutan’s energy generation portfolio is considered as type 2 adaptation, related to system change and resilience building in the climate change context.
  2. Assess the vulnerability of the project components to future climate change and recommend adaptation options for climate-proofing of the design. This is considered as type 1 adaptation, related to climate proofing.

The rationale for diversification is related to the expectation that climate change impacts on the cryosphere and hydrology in Bhutan will lead to less reliable flows, in particular outside the monsoon season. This will make hydropower a less reliable source of energy, which may not be sufficient during the dry season. During these periods outside the monsoon season, the climate in Bhutan is characterized by clear skies and daily patterns of wind. This intuitively makes solar and wind suitable energy sources to complement hydropower.

The CRA concludes that this rationale holds when validated with future scenarios of climate change and hydrological changes. These project more erratic flows, meaning on one hand more extremes on the high end (floods), in itself posing risks for hydropower infrastructure, but also through increasing sediment loads and risks of exposure to landslides and glacier lake outburst floods. On the other hand, a small increase in frequency and length of hydrological droughts is projected. Furthermore, projections of wind speed and incoming solar radiation indicate more or less stable conditions compared to the present day climate, further substantiating the rationale for portfolio diversification.

For adaptation and climate proofing the main recommendation is to verify that the proposed drainage systems at the sites are sized for extreme flows that are 20-30% larger in magnitude than current extremes. This is valid across return periods. The second high priority recommendation is to design foundations of solar, wind, and transmission infrastructure to withstand increased erosion rates and substantially increased risk of landslides in landslide prone areas. A third recommendation is to take into account lower production for solar panels at increased frequency of heat stress, as well as in the sizing of capacity of transmission infrastructure, which may have reduced capacity during periods of high heat stress.

Nature-based Solutions (NbS) can help ensure the long-term reliability of water resources. Research has shown they can – depending on circumstance – be more cost-effective and longer-lasting than grey infrastructure, while generating multiple co-benefits for carbon, biodiversity and human health. Despite the promise of NbS, however, water sector actors and their financiers usually prioritize investments in traditional grey infrastructure because they are more familiar with its costs, benefits and returns. Most of them are unfamiliar with how to develop and assess the value of NbS projects, though research shows they’re interested in tapping into their multi-faceted benefits.

The Financing Nature for Water Security project of The Nature Conservancy (TNC) aims to produce and disseminate guidance that enables water sector actors (government agencies, water utilities, grass-root NGOs) and their funders (donors, development banks and private investors) to invest in NbS-WS, at scale, by mobilizing sustainable funding and repayable financing. The project comprises of technical modules, guidance documents, supporting databases and training materials.

FutureWater has been contracted by TNC to support the development of one of the content modules assembled under the project. The module “Technical Options” will help the reader understand the water security challenge(s) they are confronted with and identify the types of NbS that could help address those challenges. In particular, Futurewater works on the creation of 12 technical factsheets to be included in an annex to the main documentation, with each factsheet highlighting the key technical aspects, benefits and risks, and economic dimensions of an NbS. In addition, an inventory of relevant NbS databases, platforms, and references is delivered.

The purpose of these calculations was to provide a definite answer about the usefulness and necessity of the proposed storm water retention areas that were seen as necessary in 2009. Various scenario calculations were performed using a Sobek model in which water levels and discharges were compared under the current and future climate and with and without integration of the storm water retention areas.

The activities in this project included:

  • Testing of discharge and water levels at critical locations for the climate scenario at different recurrence times (flood risk assessment using climate scenario),
  • Comparison to the results of the flood risk assessment using historical climate data,
  • Integration of storm water retention areas in the Sobek model and analysis of their impact on water levels, discharge  at critical locations (usefulness and necessity for storm water retention areas, answer to LBW),
  • An initial estimate of critical locations along specific flood defense barriers for the different scenarios (high resolution comparison of water levels and defenses barrier heights) and
  • A comparison of the results with a number of previously conducted studies.

During the project, the flood risk assessment method, which was developed by Arcadis in 2020, was (further) automated, so that the method can be applied more quickly and for other comparable projects within Vechtstromen Water Board. Based on the results of the calculations, clear advice could be given on the usefulness and necessity of the proposed storm water retention areas as they were proposed in 2009.

More information about the method for standardizing regional flooding that is used by the Vechtstromen Water Board can be found on the following website (in Dutch): https://www.vechtstromen.nl/over/klimaat/wateroverlast/normering/werkt-normering/

This glacio-hydrological assessment delivered river flow estimates for three intake locations of hydropower plants in Nakra, Georgia. The assessment included the calibration of a hydrological model, daily river discharge simulation for an extended period of record (1980-2015), and the derived flow duration curves and statistics to evaluate the flow operation of hydropower turbines. The daily flow calculations for the three sites (HPP1, HPP2 and HPP3) can be used in the hydropower calculations, and to assess the overall profitability of the planned investment, considering energy prices, demand, etc.

In the Nakra basin, glacier and snow model parameters were tuned to obtain accurate river flow predictions. Also, the latest technology of remote sensing data on precipitation and temperature (product ERA5) was used to reduce potential errors in flow estimates. Even though these flow estimates are useful for short-medium term evaluations on profitability of the planned investment, climate change pose a challenge for long-term evaluations. Glacier-fed and snow-fed systems, such as the Nakra basin, are driven by a complex combination of temperature and precipitation. Due to future increasing temperature, and changing rainfall patterns, glacier and snow cover dynamics change under climate warming. This can lead to shifts in the flows, like a reduction in lowest flows, and higher discharge peaks when the hydrological system shifts towards a more rainfall-runoff influenced system (Lutz et al. 2016). This can jeopardize the sustainability of the project on the long-term. To provide a better understanding of future river flows, it is recommended to develop a climate change impact assessment.

Asian Development Bank (ADB) is supporting the Government of Kazakhstan in it’s “Wastewater Treatment Plants Reconstruction and Construction Program”. The overall aim is to improve the wastewater treatment facilities in the 53 cities across Kazakhstan. The Program will be implemented through a phased approach. During the first phase five Wastewater Treatment Plants in Stepnogorsk, Zhezkazgan, Satpayev, Balkhash and Zhanatas are to be financed by ADB.

FutureWater has undertaken a climate risk and adaptation analysis for those facilities. FutureWater has extended and updated a previous climate risk assessment (CRA). The original CRA was based on the CMIP3 projections and only some selected climate models were used. FutureWater has updated the original CRA by using downscaled CMIP5 projections (NASA-NEX) for RCP4.5 and RCP8.5 and the full range of climate models. Also adaptation strategies were refined.

Results show that the key climate risks includes a projected increase in mean annual temperature for all five waste water treatment plants and hottest day temperature are in the same range. Those higher temperatures might negatively affect operations and efficiencies of the plants. Mean annual precipitation is projected to increase for all five treatment plants. Potential risk of flooding of the infrastructure or large influx of storm water is determined by wettest day precipitation. An increase in wettest day precipitation is projected to be between 6% to 14%. Zhanatas and Stepnogorsk waste water treatment plants are most vulnerable regarding the risk of increased severity and frequency of floods.

Adaptation interventions to those projected climate changes are explored in the initial environmental examination (IEE) and will be further developed during the detailed design phase. The following broad adaptation options are foreseen:

  • selection of sites less prone to flooding for the two new WWTP,
  • flood protection of the three WWTP to be rehabilitated,
  • selection of sewerage technology that will function under higher temperatures,
  • awareness raising of staff, and
  • monitoring to avoid sewer overflows during storm events.

The Asian Development Bank is supporting the Government of Indonesia in developing its water infrastructure. Impact of climate change and potential adaptation to those changes are evaluated. One component of the project is to assess water availability for all Indonesian catchments currently and under changing climate. FutureWater has supported the program by developing a climate risk screening approach to rapidly assess current water resource availability and the impact of climate change on this.

Various rapid assessment assessments have been tested and the Turc implementation of the Budyko framework has been proven to be effective for basins in Indonesia. ERA5 past climate and NASA-NEX GDDP climate projections have been applied for all basins in Indonesia. Results show that all Indonesian basins are likely to see an increase in runoff over the coming century. However, variability in runoff will increase, with more extreme dry and wet periods. This will have implications for water management planning and climate related hazards such as more prolonged droughts and higher risks of flooding.

Recently, the Central Asia Regional Economic Cooperation (CAREC) Program introduced agriculture and water as a new cluster in its strategic framework. Recognizing the complexities of the water sector and the existing landscape of cooperation activities, the strategic framework proposes a complementary approach that uses the strengths of CAREC to further promote dialogue on water issues. A scoping study was commissioned, supported by the Asian Development Bank (ADB), to develop a framework for the Water Pillar for further consideration by the governing bodies of CAREC. It was agreed that the initial focus of the Water Pillar should be on the five Central Asian states with consideration given to expanding to other CAREC member countries over time.

The objective of the study is to develop the scope of a Water Pillar Framework that includes a roadmap of national development interventions for each of the five Central Asian Republics that responds to the prevailing challenges and opportunities in water resources management.

The framework will be derived from three specific outputs:

  • Output 1: Projection of future availability and demand for water resources for the Central Asia region up to 2050 including implications of climate change.
  • Output 2: Identification of future water resources development and management opportunities in the form of a sector specific framework for water resources infrastructure taking into consideration sustainability issues through a comparative assessment of cost recovery mechanisms and operation and maintenance (O&M) practices.
  • Output 3: Preparation of a framework for policy and institutional strengthening that addresses common themes and issues related to national water resources legislation and the capacity and knowledge development needs of water resources agencies with an emphasis on economic aspects and sustainable financing.

For this work, several consultants were recruited. FutureWater provides key inputs on the climate change and water resources aspects, including desk review, stakeholder consultations across the five regions and across all sectors, and analysis of climate change risks and identification of adaptation options that have a regional dimension and can be taken up through regional or bilateral cooperation.

Several catchment plans have been already developed through the Dutch-funded Water for Growth programme. FutureWater played a paramount role in this programme by developing the water allocation models (WEAP) at national level and for several priority catchments. Moreover, FutureWater provided capacity building to local experts and staff on using and further developing and fine-tuning those WEAP models.

The current project aims at developing two catchment plans, for:

  1. Mukungwa catchment
  2. Akagera Lower catchment

These catchments were included in a previous national-level water resources allocation study performed by FutureWater. Four catchments were selected from this national level assessment to make catchment-level WEAP models to inform the catchment plans. A next step for the Rwanda Water Resources Board (RWB), is to prepare catchment plans for the above two catchments, for which this project will be instrumental.

For the two catchments, this study aims at (1) providing detailed information on available and renewable water resources, both surface and groundwater, and their spatial and temporal variations; and (2) to map and quantify water uses and water demands, to develop water allocation models that can be used as tools to manage operationally and plan the catchments in a sustainable way. The scenarios (options) assessed can also be essential input into the catchment management plan. This study will produce water allocation models based on current and potential uses in a time-horizon of 30 years.

The project is carried out in collaboration with a team of local experts and one of our partners Dr. Kaan Tuncok as a team leader.

Mukungwa and Akagera Lower catchments

This hydrological assessment delivered river flow estimates for an intake location of a potential hydropower plant in the Lukhra river, Georgia. The assessment included a tuning of a hydrological model based on knowledge of neighboring basins, daily river discharge simulation for an extended period of record (1989-2019), and the derived flow duration curves and statistics to evaluate the flow operation of hydropower turbines. The daily flow calculations for the site can be used in the hydropower calculations, and to assess the overall profitability of the planned investment, considering energy prices, demand, etc.

In the Lukhra basin, snow model parameters were tuned to obtain accurate river flow predictions. Also, the latest technology of remote sensing data on precipitation and temperature (product ERA5-Land) was used to reduce potential errors in flow estimates. Even though these flow estimates are useful for short-medium term evaluations on profitability of the planned investment, climate change pose a challenge for long-term evaluations. Snow-fed systems, such as the Lukhra basin, are driven by a complex combination of temperature and precipitation. Due to future increasing temperature, and changing rainfall patterns, snow cover dynamics change under climate warming. This can lead to shifts in the flows, like a reduction in lowest flows, and higher discharge peaks when the hydrological system shifts towards a more rainfall-runoff influenced system (Lutz et al. 2016). This can jeopardize the sustainability of the project on the long-term. To provide a better understanding of future river flows, it is recommended to develop a climate change impact assessment.