Urban Water Supply and Sanitation Sector Project (RRP SOL 51271-001) CLIMATE CHANGE ASSESSMENT I. BASIC PROJECT INFORMATION Project Title: Solomon Islands: Urban Water Supply and Sanitation Sector Project (UWSSSP) Project Cost ($ million): 92.82 Location: Honiara and other cities Sector: Water and other urban infrastructure and services Theme: Inclusive economic growth, environmentally sustainable growth Brief Description: UWSSSP will improve access to safe water and improved sanitation in urban and peri-urban areas of Solomon Islands. About 152,000 (24%) of the Solomon Islands population live in urban and peri-urban areas, the largest of which is greater Honiara, with an estimated population of about 105,000. Based on medium growth projections, Solomon Islands urban population may grow to 430,000 by 2050 while the population of greater Honiara is expected to surpass 300,000. Specifically, the four Outputs are: Output 1 - Secure and safe urban water supplies. New and rehabilitated infrastructure for water supply, treatment, distribution and storage infrastructure for Honiara, and potentially in the urban areas of Auki, Noro, Gizo, Munda and Tulagi. This may include infrastructure in flooding and rainfall affected zones. Water supply is from springs, rivers and wells. Output 2 - Effective, efficient and safe urban sanitation services. New and rehabilitated infrastructure for waste water collection, treatment and dispersal for Honiara. This may include infrastructure in flooding and rainfall and coastal incursion affected zones Output 3 - Enhanced awareness of hygiene and water issues and sustained improved hygiene behavior. Output 4 – Improved financial and technical sustainability of water management utility (Solomon Water, SW). Source: Asian Development Bank (Feasibility Study) II. SUMMARY OF CLIMATE CHANGE FINANCE Project Financing Climate Finance Amount Adaptation* Mitigation Source ($ million) ($ million) ($ million) Asian Development Bank Sovereign Project Grant (Asian Development Fund, 9 0.962 0 ADF) Sovereign Sector (concessional loan): Ordinary 28 2.994 0 capital resources Cofinancing European Union (ADB administered grant) 20.35 2.176 0 World Bank (Concessional Loan) 15 1.604 0 Counterpart Solomon Water 9 0 0 Solomon Islands Government 11.47 0 0 Totals 92.81 7.735 0 ADF = Asian Development Fund. Source: Asian Development Bank (RRP Document). Climate Risk Assessment (Appendix 1) *Note on allocation of climate finance across financing agencies: The total project climate costs are estimated to be $7.735 million. These are related to many project outputs, sub-outputs and activities. The three participating international financing agencies (ADB, EU and WB) contribute to all these activities, however the precise details of which agency finances which activity have not been determined. Hence the climate costs are allocated to the agencies in the same proportion as the overall budget supported by that agency. As ADB is administering all funds, for international reporting purposes, the figure of $6.312 should be reported under ADB climate finance. III. SUMMARY OF CLIMATE RISK SCREENING AND ASSESSMENT Solomon Islands is highly vulnerable to natural hazards, including severe tropical storms and sea surges. Climate change projections indicate that climate related risks will increase. The ADB Concept Paper (October 2017) determined that the climate change impacts on the project would be high. Hence, no AWARE report was prepared, but a full climate risk assessment was directly undertaken (see Appendix for details of the methodology, data used and findings). A. Sensitivity of Project Component(s) to Climate or Weather Conditions and the Sea Level Initially, all potential climate related risks were considered for the two project Outputs that have infrastructure components (i.e. Outputs 1 and 2). The following table summarizes the climate related risks for which it was determined that additional investigation was necessary (and the pertinent project Outputs). Climate related risk with potential impacts UWSSSP Output Sensitivity 1: Water 2: Supply Sanitation Reduced precipitation levels can decrease the availability of both surface water and X groundwater. High-intensity precipitation may increase erosion. X X Larger sediment loads may result in more rapid sedimentation of storage reservoirs, X reducing storage capacity. Changes in the amount of rainfall may affect the performance and operation of water X systems. Increases in precipitation may put pressure on urban drainage systems while sewerage X X systems may become more difficult to operate and maintain if precipitation levels and discharge decline. In other instances (particularly in warm areas), the efficiency of these processes may X be reduced if critical thresholds are exceeded. Temperature increases may result in a reduction of surface water availability by X decreasing runoff and increasing evaporation from lakes and reservoirs. Higher temperatures may increase agricultural water demand due to decreasing. X Increases in periods of intense heat may result in higher water demands for domestic X and industrial uses. Service disruptions may increase due to breakdowns in water distribution pipelines X from extreme events, such as unseasonal precipitation patterns and flash floods. The structural integrity of basic water infrastructure may deteriorate due to floods and X X periods of intense heat and cold. Increases in the intensity of floods may result in the contamination of water sources X and may increase the incidence of waterborne and water-related diseases Saline intrusion in low-lying coastal areas may contaminate aquifers and force currently X secure water sources out of use. Coastal storms in combination with sea-level rise can damage coastal water supply X X and wastewater treatment facilities. Ocean discharge from treated wastewater outfalls can be impaired by sea-level rise, X particularly during high tides or storm surges. B. Climate Risk Screening Using the table from Section A above, the level of risk for each climate factor for each project component and each project sub-component was determined. Risk level was determined as a function of (i) the likelihood of the hazard happening and (ii) the consequences of the hazard happening. Taking into account projected climate change, the following project sub-components were determined to face either high or extreme climate risks: Water supply for Honiara Extreme precipitation leading to increased floods that may directly or indirectly (through erosion) physically undermine the newly constructed infrastructure, this risk applies to: o the new source (Lungga river: intake, water treatment plant, storage, pumping stations and uphill transportation, associated channels to transport water to the network); and o the rehabilitated and expanded storage, transportation and distribution reticulated network (Honiara trunk mains, storage tanks and distribution pipes); Extreme precipitation events may cause turbidity that undermine performance of Kongulai spring; Reduced short-term precipitation may decrease water volume available from Kongulai spring; Coastal storms in combination with sea-level rise can damage coastal water supply facilities (distribution pipes); Larger sediment loads may result in more rapid sedimentation of storage reservoirs, reducing storage capacity, and; Climate change (through increased consumer demand) may lead to need for larger sizing of storage tanks, to act as buffer to increase rainfall variability. Sanitation in Honiara Ocean discharge from treated wastewater outfalls can be impaired by sea-level rise, particularly during high tides or storm surges; Increased precipitation and floods may directly or indirectly (through erosion) physically undermine the new sanitation infrastructure (pumps, pipes and outfalls); Increased precipitation and floods may directly or indirectly (through erosion) physically undermine the newly created septage facilities; Increases in the intensity of floods may result in the contamination of water sources and may increase the incidence of waterborne and water-related diseases. Water supply to Gizo Climate change leads to water supply from the upland lake unable to meet the growing demand; and Climate change leading to damage to the infrastructure. Water supply to Auki, Munda, Noro and Tulagi (through application of precautionary principle, given uncertainties and unknowns) Increased storms and/or floods may directly or indirectly (through erosion) physically undermine any newly constructed water supply infrastructure (i.e. abstraction and withdrawal equipment, treatment plants, storage facilities, main trunks and distribution pipes); Increased sediment loads may result in more rapid sedimentation of storage reservoirs, reducing storage capacity; Climate change may lead to need for larger sizing of storage tanks, to act as buffer to increase rainfall variability; and, Coastal storms in combination with sea-level rise can damage coastal water supply facilities. C. Climate Risk Classification: See Appendix, notably Annex 1 in the Appendix D. Climate Risk and Adaptation Assessment For each project sub-component determined to be at high or extreme risk to climate or climate change, the project design was assessed and the measures taken to adapt and to ensure resilience were assessed. A gap analysis was undertaken and recommendations provided. As appropriate, further additional adaptation measures were recommended. The costs of measures already taken and