Health Quality Assessment of the Beeralla Stream in Ella with Respect to the Selected Physico-Chemical and Biological Factors in Water: An Assessment of the Effects of Unsustainable Tourism Practices

Beeralla stream is a tributary of Kirindioya flowing through Ella, an enchanting town and well-known tourism destination. The stream is particularly vulnerable to pollution from tourism-related activities. The present study intends to assess the spatio-temporal water quality and levels of organic pollution in the surface water of the stream. After considering different land use patterns, parameters such as pH, Conductivity, Temperature, Total Suspended Solids (TSS), Turbidity, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Nitrate and Total Phosphate (TP) were measured in surface water samples in selected locations from March to November 2021. Aquatic macroinvertebrates and dragonflies were identified at the family level at the time of water sample collection. All measured surface water quality parameters were significantly different among sampling locations (p < 0.05). The mean values for Nitrate, TP, BOD5, and COD in mid segment of the stream were significantly higher than those of other segments (p < 0.05). This area is influenced by uncontrolled wastewater discharges of riverine-encroached hotels and restaurants. Nitrate, TP, TSS, BOD5, and COD content were significantly higher in January and March than in other months (p < 0.05). Collectively, TSS, turbidity, DO, phosphate, COD, and BOD5 levels in the stream exceeded the Sri Lankan ambient water quality standards. A total of 15 species of macroinvertebrates were identified and the water quality of Beeralla stream acts as an organic pollution spot with poor water quality based on the values of Shannon Wiener Diversity Index (1.31–1.94) and Family Biotic Index (5.56–8.24). Stream subjected to this study enhances recreational value by encouraging the tourism industry in Ella. The results of this study highlight the urgent need to adopt effective pollution management with the active involvement of all the stakeholders in Ella. This is the first study to be conducted in a freshwater ecosystem in Ella aimed at examining the detrimental consequences of tourism activities on water pollution.