Plant Archives Journal home page: www.plantarchives.org The present study was carried out to evaluate the water quality of the Biodiversity Heritage Site i.e., Ameenpur Lake (Telangana, India) using Water Quality Index (WQI) and spatial distribution technique. The water samples were collected during Pre-Monsoon, Monsoon and Post-Monsoon seasons of the year 2019-20 and analysed for physico-chemical parameters as per the American Public Health Association (APHA) standard methods for water and wastewater treatment. The WQI were calculated by using the standard method of Weighted Arithmetic Water Quality Index (WAWQI) and National Sanitation Foundation Water Quality Index (NSFWQI). The WAWQI and NSFWQI methods indicated that overall water quality of the lake was found to be poor in all the seasons. According to the WAWQI map, majority of the samples were found be in the poor water quality in all the three seasons and according to the NSFWQI map, all the samples were found to be bad in condition in all the seasons. The same is represented in the spatial distribution maps. The decline in the quality of lake water is due to various anthropogenic activities like enrichment through surface and agricultural runof and also due to discharge of untreated sewage and industrial efuents. Keywords: Ameenpur Lake, Biodiversity Heritage Site, Water Quality Index, Geo-spatial tools, Spatial Distribution. EVALUATION OF WATER QUALITY STATUS OF AMEENPUR LAKE, HYDERABAD, TELANGANA, INDIA USING WATER QUALITY INDEX (WQI) AND GEO-SPATIAL TECHNOLOGY N.S.Srinidhi 1* , P. Madhusudhana Reddy 2 , and M. Anji Reddy 3 1Department of Forest Ecology and Climate Science, Forest College and Research Institute, Mulugu, Siddipet, Telangana, India 2Department of Geology, BRAOU, Hyderabad, Telangana, India 3Centre for Environment, JNTUH, Hyderabad, Telangana, India Email: srinidhifcri@gmail.com (Date of Receiving-12-01-2021; Date of Acceptance-31-03-2021) ABSTRACT e-ISSN:2581-6063 (online), ISSN:0972-5210 Plant Archives Volume 21, No 1, 2021 pp. 1917-1923 DOI Url: https://doi.org/10.51470/PLANTARCHIVES.2021.v21.no1.267 INTRODUCTION Surface waters play a crucial role both in social and economic development, especially when it comes to Freshwater lakes and rivers. They are the most benefcial resources to the society in many ways such as agriculture; fshing, as a drinking water source, for industrialization and most importantly support rich biodiversity. A lake is a watershed area in which its quality depends upon every component of that ecosystem (Indra 2006). Its quality depends on the Topography of the surrounding area, soil type, geology and vegetation as it determines the kind of materials entering into lake (Dong et al., 2010). In the last few decades, the haphazard population increase, urbanization and industrial development are the major reasons for deteriorating both the rural and urban water quality and ultimately afecting the aquatic ecosystem. Under this pressure with worldwide environmental concerns most of the urban and rural lakes have vanished (Iscen et al., 2008; Prasanna et al., 2010). Once the groundwater and surface water quality is contaminated, its quality can’t be restored by stopping the pollutants from the source (Ouyang, Y et al., 2006). According to the WHO, CPCB, BIS and ICMR about 70% of the India’s water quality is polluted due to discharge of industrial efuents and sewage wastewater making the natural stream unft for consumption (Nida Rizvi 2016). Evaluating the water quality is crucial before its use for various purposes such as drinking, agricultural, fshing, recreational and industrial use. Hence monitoring of surface water quality has become indispensable (Sashikkumar M.C. 2013). It therefore becomes imperative to regularly monitor quality of surface water resources and to device ways and mean to protect it. Water quality index (WQI) is considered one of the best tools to provide information on the quality of water to the concerned citizens and policy makers. This method also gives an idea about the overall quality of water to the concern policy makers (Asadi et al., 2007). For both assessment and management of surface water it thus becomes an important tool as assessment of water quality helps in knowing the water suitability for various purposes. In 1970’s the WQI was developed to monitor water quality changes which was proposed by Horton (1965) and Brown et al., (1970). Later Bhargava (1983 a,b,c) introduced the water quality index concept in India and gave an index scale ranging from 0 to 100 for highly polluted to unpolluted water. The prime objective of the index is to turn the diferent water quality parameters into information, which is comprehensible and usable by the layman (Brown et al., 1970 and Boyacioglu H. 2007). Using the biological, chemical and physical properties, the WQI is usually illustrated and based on these properties; the quality of water can be expressed via a numerical index (i.e. Water Quality Index, WQI) by combining measurements of selected water quality variables (Horton 1965). The index is important in evaluating the water quality of diferent