Modeling of Hydro Level and Hydroelectric Power in Kothmale Reservoir, Sri Lanka

The Kotmale Reservoir, located in the Kotmale area of the Nuwara Eliya District, Central Province, Sri Lanka (7°03′39″ N, 80°35′50″ E), supplies water to the Kotmale Hydropower Station (7°07′41″ N, 80°34′42″ E). The power station has three 67 MW turbines with a total installed capacity of 201 MW, making it the second-largest hydroelectric power station in Sri Lanka.

This study aimed to examine the relationship between daily water releases for hydropower generation and daily energy production. Daily operational data were obtained from the Mahaweli Authority of Sri Lanka. The main variables analyzed were daily release volume (million cubic meters, MCM) and daily energy generation (GWh).

Regression analysis was employed to investigate the relationship between these variables. The results indicated a strong positive correlation between release volume and energy generation, showing that higher water releases result in greater electricity production. The fitted regression model is  log₁₀? ENERGY = 0.075 + [0.918×log_10? RELEASES].

The regression coefficient (0.918) demonstrates a strong positive association between water releases and energy generation. The findings confirm that daily water releases for hydropower generation are a significant predictor of daily energy output at the Kotmale Hydropower Station, highlighting the importance of reservoir operation in optimizing hydroelectric power production.