Multi-purpose reservoirs support socioeconomic development by providing irrigation, domestic water supply, hydropower, and other services. However, impoundment of water impacts instream aquatic ecosystems. Thus, the concept of minimum environmental flows (MEFs) was established to restore the benefits of naturally flowing rivers by specifying minimum flow rates to be maintained downstream of dams. But varying legislative contexts under which multi-purpose reservoirs operate may not always necessitate MEF releases. To what extent the release of MEF affects other sectoral benefits remains an open-ended and possibly a site-specific inquiry. A related issue is − how does the order in which releases are prioritized influences sectoral performances? We analyse these issues for the Nagarjuna Sagar reservoir, one of the largest multipurpose reservoirs in southern India. We formulate two versions of a multi-objective decision problem. PF_MEF formulation prioritizes MEF releases over releases for water demand satisfaction, followed by hydropower releases. PF_nMEF formulation follows the regional legislative rule releasing first for demand satisfaction, followed by hydropower and MEF releases. The objectives include: annual demand deficits (minimize), hydropower production (maximize), reliability of maintaining MEF (maximize), and reliability of non-exceedance of high flows downstream (maximize). A dynamic rule using radial basis functions (RBFs) specifies releases as a function of reservoir storage and the Borg multi-objective evolutionary algorithm is used to identify the Pareto approximate solutions. The reliability of MEF satisfaction, annual demand deficits, and hydropower production attained across the Pareto-optimal strategies obtained for PF_MEF (PF_nMEF) formulation is 86–99 % (63–80%), 47–1063 (17.6–340) Mm3, and 3452–3703 (3408–3650) GWh, respectively. Results thus indicate that prioritizing MEF releases improves can meet MEF requirements without significant compromises in other objectives. We hypothesize that similar investigations may reveal how simple modification of release order may improve ability of other reservoirs to meet environmental goals.