Introduction: The Sistan region faces serious challenges in irrigation water management due to its geographical and climatic conditions. Water scarcity, drought, and reduced surface flows of the Hirmand River have made the existing water wells the primary source of water supply in the region. Effective planning for the optimal use of these well water resources is therefore essential. This study aimed to investigate the environmental factors influencing water consumption management policies in the Sistan region. A secondary objective was to identify appropriate strategies for the optimal and sustainable allocation of Nimruz well (Chah-e Nimeh) water resources. Methods: A descriptive-analytical approach was applied, using the Strengths, Weaknesses, Opportunities, and Threats (SWOT) matrix and the Quantitative Strategic Planning Matrix (QSPM) to assess environmental factors and select appropriate water allocation strategies. Subsequently, Positive Mathematical Programming (PMP) combined with the Constant Elasticity of Substitution (CES) production function was used to optimize agricultural activities based on well water use under drought conditions. Data from 2022–2023 were collected through questionnaires and consultations with relevant organizations in Sistan and analyzed using GAMS software. Findings: The SWOT analysis revealed that internal factors (strengths and weaknesses) scored 2.286 and external factors (threats and opportunities) scored 2.436. These values indicate the need for defensive (WT) strategies to improve water allocation and exploitation policies in the region. Under mild to severe drought conditions, well water resources are projected to decline by 9.57% to 49.23% compared to the base year. In response, farmers are expected to reduce the cultivation area of onions, melons, watermelons, and alfalfa, and shift toward wheat and barley. Total gross farm profit is estimated to decrease by 0.53% to 3.67%, while the economic value of water rises from 1,184 to 2,377 rials per cubic meter. Conclusion: Based on the findings, the following measures are recommended: reforming water pricing policy and establishing compensation mechanisms under conditions of increasing water scarcity; removing crops with low economic and physical productivity from cultivation patterns during drought; and implementing defensive strategies for the proper management of well water allocation policy in the Sistan region.