Improving the quality of residual water and increasing agricultural production is necessary to achieve food sovereignty in water deficit conditions. The research was carried out to evaluate the operation of the precision lagoon for agricultural irrigation purposes by determining the geometric and hydraulic parameters, kinetic coefficients and dissolved Oxygen using the Streeter & Phelps model. The main results indicate the presence of a facultative lagoon with a hydraulic retention time of 6.7 days, flow rate of 1 641,6 m3 day-1 contributed by 41 312 inhabitants, solar penetration of 0.20 m, presence of green algae, 0,36 day-1 deoxygenation coefficient, 0,60 day-1 reaeration coefficient, 0,09 day-1 sedimentation coefficient, 0,45 day-1 total removal coefficient, dissolved Oxygen of the effluent of 2 mg L-1, initial dissolved oxygen deficit of the influent and effluent of 8,4 mg L-1 and 2,43 mg L-1 respectively. These indicate that the effluents can be used as wastewater reuse for irrigation of cooked food crops according to the recommendations of the World Health Organization. Keywords: wastewater, kinetic coefficients, dissolved Oxygen, hydraulic parameters, reuse.