Crida For Drought Adaptation In The Limar¨ª Watershed, Chile
The project in the Limar¨ª watershed, Chile, was implemented by UNESCO to improve drought and water resource management. It is a textbook example of the implementation of the CRIDA methodology. The case, with high potential risk but also high uncertainty under possible future climate scenarios, proves the utility of CRIDA to find suitable solutions for complex cases in cooperation with stakeholders.
Contexto
The Limar¨ª watershed in Chile results from the confluence of two Andean rivers. In the recent decades the continuous reduction in water supply and low reservoir levels have led to droughts and put pressure on the agricultural sector, enhanced by the impacts of population growth and climate change.
The unusual long drought that started in 2009 led to low reservoir water levels and continued reductions in water supply. As a result, large agricultural areas were abandoned.
Acciones
In response to the mega drought UNESCO initiated the project back in 2014. First a stress test to analyze the impact of climate change on water security was developed. This was the implementation of CRIDA step 1 and 2 in which the decision context was established in cooperation with stakeholders to carry out a bottom-up vulnerability assessment.
The Limar¨ª case has a high level of concern since climate change poses a high risk on the water security, but the analytical uncertainty is also high. In this case a combination of robust and flexible actions is usually recommended. During the implementation of CRIDA step 3, the possible adaptation actions were listed and evaluated with input from the stakeholders. Subsequently, some actions were combined into adaptation pathways to increase the robustness and/or flexibility.
Next, the four possible pathways were evaluated in terms of total cost through the Discounted Cash Flow methodology for three different possible climate scenarios. Similarly, the total benefit was calculated for all scenarios through the reduction in unmet water demand so increase in yield thanks to the adoption pathways. One adaptation pathway came out as the overall winner after CRIDA Step 4.
Lastly, CRIDA step 5 examined how the adaptation pathway can be institutionalized and formed recommendations. This is a key part of the CRIDA methodology since the implementation can only be successful if it is integrated into management and policy documents and the necessary budgets, including maintenance costs for example, are allocated.
Outcomes
Stationarity is no longer a baseline assumption because of climate change, making planning for the future more complex. The bottom-up vulnerability assessment is useful because it combines historical data and climate models to determine the future risk level. This case proves that even though the uncertainty remains high, the CRIDA framework facilitates informed decision making.
The CRIDA application resulted in 4 possible adaptation pathways that would secure water to watershed under different possible climate scenarios. After the net benefit analysis, one pathway came out as the ¡°winner¡± under all climate scenarios. To facilitate the implementation the key institutional, budgetary and legal barriers, the actors and solutions were identified.
In 2024, the President of the Republic of Chile, Gabriel Boric, announced the call for tender to design desalinization plants for the region, in line with the recommendation of the CRIDA Analysis. The Chamber of Deputies approved the project, allowing work to start in the last quarter of 2024.
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