Assessing the risks tied to agricultural crop production in watersheds impacted by climate change presents a considerable challenge for effective water resource management. In response to this pressing issue, our study introduces a new metric called the Crop Cultivation Risk Index (CCRI). This index is formulated to quantify the risks of crop failure from the water resources management point of view by considering various critical factors, including evaporation rates, minimum water requirements for plant growth (MRW), and the agricultural standardized precipitation index (aSPI). The analysis of the Tashk watershed revealed significant numerical insights. Over 50% of the catchment area exhibited CCRI values ranging from 0.5 to 1.3, indicating a moderate to low risk of wheat crop failure in these regions. This trend was particularly pronounced in the central sections of the watershed, where conditions are less favorable for crop growth. These findings suggest that stakeholders in these areas can adopt more resilient agricultural practices, knowing that the risk of failure is relatively manageable. Conversely, regions displaying CCRI values above 1.3, reaching a maximum of 2.3, signify optimal conditions for wheat cultivation. Specifically, the highest CCRI values, which were recorded at 2.31, are predominantly found in the northwestern and southeastern sections of the catchment. These areas demonstrate a strong capacity for supporting wheat production, encouraging farmers to focus on these regions for potential agricultural expansion. Such numerical insights can facilitate informed decision-making, ultimately contributing to more effective resource management strategies and sustainable agricultural practices in the face of climate variability.