One of the major challenges facing most irrigation and drainage projects—particularly large-scale downstream dam networks—is their incomplete implementation, structural deficiencies, and the slow pace of construction activities in recent years. The Sahand Irrigation Network in Hashtrud County, comprising 8,500 hectares of newly developed land and 600 hectares of rehabilitated land, began construction in 2005. However, by 2024, only 2,800 hectares of the network had been fully completed and commissioned. This study employed a qualitative approach (grounded theory) to explore strategies for completing the irrigation network. Data were collected through in-depth semi-structured interviews. Participants were selected purposively, and theoretical saturation was achieved after interviewing 29 participants. The collected data were coded through three stages: open, axial, and selective coding. Open coding resulted in 91 concepts, which were categorized into 29 subcategories during axial coding. Selective coding led to the identification of 13 overarching categories: “improving the project’s technical conditions,” “enhancing land acquisition procedures,” “utilizing local potential,” “ensuring investment security,” “awareness-raising, trust-building, and cultural development among farmers,” “ensuring commitment fulfillment,” “the project’s inherent (natural–economic) capacities,” “bottom-up planning,” “leveraging operational capacities,” “governmental support,” “facilitating investment conditions,” “attracting investors through land-lease mechanisms,” and “completing the network through intersectoral coordination.” The framework proposed in this study can serve as a practical and policy-relevant foundation for accelerating the completion, development, and sustainable operation of similar irrigation networks across the country.