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.