The Devoll River, one of the sources of Seman River, joins Osum River in the proximity of KuÇova. The above are both used for irrigation purposes. The studies performed (over a period of four years 2003-2006) were aimed at determining the water quality of the Devoll and Osum rivers together with their impact in agriculture. The maximal sodium values recorded in the Devoll and Osum rivers were 1 mg/L (2003) and 0.66 mg/L (2006) respectively. Magnesium levels ranged from 2.67 mg/L (2003) to 2.96 mg/L (2006) with a 4 year average of 2.79 for the Devoll river and 2.02 mg/L (2006) to 3.55 mg/L (2005) with a 4 year average value of 2.57 mg/L for the Osum river. The nutritious elements levels were generally low. The average value of N - NO3- recorded in the Devoll waters reached 2.02 mg/L, with a maximal value of 5.88 mg/L (2006). The average value of N - NH4+ was calculated to be 1.12 mg/L, while the maximal value reached 2.1 mg/L (2006). PO43- and K+ had a maximal value of 0.1 mg/L (2005) and 11 mg/L (2006) respectively. The last value was 5.5 times bigger than the allowed one. For the Osum River the maximal values of N - NO3- and N - NH4+ were 9.02 mg/L (2006) and 3.22 mg/L (2006) respectively. The maximal values of PO43- and K+ were recorded to be 0.228 mg/L (2004) and 12 mg/L (2006). This maximal value is six times bigger than the allowed value. On average nutrient concentrations were higher in 2006 compared to previously recorded values. These concentration levels, with the exception of K+, were however within the FAO standard levels.