Adyar River Research Articles

Seasonal Dynamics and Avian Diversity along the Adyar Riverbank: Insights from a Year-Long Survey

The avian survey conducted along the Adyar Riverbank (Manapakkam) from January 2023 to December 2023 documented a total of 3120 individual birds across 75 species from 16 avian orders, highlighting the significant biodiversity within this urban ecosystem. This study aimed to assess seasonal variations in bird diversity and abundance, emphasizing the river’s role as an important habitat. The highest diversity was observed during winter, specifically in February 2023, with a diversity index of 296.80 and a Simpson’s index of 0.22. A total of 36 species and 636 individuals were recorded. In contrast, the lowest diversity was observed in summer, particularly in July 2023, with a diversity index of 29.29 and a Simpson’s index of 0.05, corresponding to 18 species and 114 individuals. The monsoon and post-monsoon periods exhibited a prominent increase in diversity due to the arrival of migratory species and improved habitat conditions. Important species recorded throughout the year included the Paddy Field Pipit, House Crow, and Rufous Treepie, while conservation-significant species such as the Black-headed Ibis and Spot-billed Pelican were also observed. Thus, the present study underscores the Adyar River’s ecological importance and highlights the need for continuous monitoring and targeted conservation efforts to maintain avian biodiversity in urban river ecosystems.

Occurrence of forever chemicals in Chennai waters, India

BackgroundPer- and polyfluoroalkyl substances (PFAS) are considered ‘contaminants of emerging concern’ due to their environmental persistence, bio-accumulative potential, and adverse effects on human health. They are widely employed in producing various goods used in daily life, such as non-stick cookware, cleaning agents, and many industrial applications in aerospace, automotive, construction, electronics, and military, all of which ultimately end up in different environmental matrices. India’s rapid economic growth necessitates a comprehensive understanding of its PFAS contamination levels and potential human and ecological exposure.ResultsThe present study reports the quantification of one long-chain and two short-chain perfluoroalkyl acids and three long-chain and two short-chain perfluorosulfonic acids and qualitative analysis using suspect screening in the waters of Chennai, Tamil Nadu, India. Samples were collected from surface and groundwater sources, including the Adyar river, Buckingham canal, Chembarambakkam lake, and the water treatment plant. The concentrations analyzed in all the samples ranged from 0.10 ng/L to 136.27 ng/L. Groundwater had some of the highest concentrations of PFAS. L-PFBS (up to 136.27 ng/L) and PFOA (up to 77.61 ng/L) are present in all the samples. The concentrations of all the target PFAS increased in the 5 to 103% range in the final treated water compared to the raw water of the water treatment plant. This treated water is distributed as a source of drinking water for the residents of Chennai. Additionally, the dominance of short-chain compounds (4–7 carbons) over long-chain compounds (> 7 carbons) was observed. Suspect screening revealed numerous precursors and other fluorinated compounds abundantly present in the samples.ConclusionsOur study revealed PFAS levels up to 136.27 ng/L in both surface and groundwater samples from Chennai. These findings raise concerns about potential risks to ecosystems and human well-being. The dominance of short-chain PFAS coupled with abundant precursors and unidentified fluorinated compounds indicates an ongoing shift toward alternatives. Conventional water treatment is ineffective in eliminating these chemicals from the water system; rather, increasing the PFAS concentrations from raw water to treated water necessitates advanced polishing steps. Industrial emissions, untreated domestic wastewater discharge, and open dump sites have been suspected as the significant sources of contamination, highlighting the need for further investigation to fully assess the extent of PFAS contamination in Chennai.Graphical

Integrated Riverside Development Along Adyar River, Chennai

Integrated Riverside Development (IRD) is a planning approach that aims to achieve sustainable development of urban areas located along riverbanks. To implement this IRD with controlled regulations, the study is focused on developing a comprehensive riverside development and river zoning regulatory framework that integrates all five main elements, with particular emphasis on economic, ecological, and social factors, in order to reduce encroachment and pollution in the study area. The objectives of the study include analyzing the current land use, recreational parks, encroachments, pollution levels, sewage disposal patterns, and solid waste dumping zones in the study area, as well as studying the socio-economic and eco-environmental aspects of the area. Additionally, identifying and analyzing the major threats to the river and developing a river zoning regulatory framework using the land use matrix technique is also included in the study objectives. The study area (Adyar River) was chosen based on social, ecological, and economic factors, and data was collected through surveys and from government offices. Using the land use matrix method, proposals for riverside development were made, and the zones were classified into development-prohibited, development-restricted, and development-optimized zones. The zones were classified based on the calculated values of Eco sensitivity for each of the three zones. Proposals were then given based on these classified zones, and the levels of development potential were determined. The proposed zoning regulatory framework is expected to have a significant impact in reducing further encroachments and improving connectivity between the city and the river. By considering socio-economic, ecological, and environmental aspects, the study recommends appropriate zoning regulations for riverfront developments that promote sustainable growth.

Assessing the Effects of Tannery Pollutants in Tamilnadu: Special Reference to Chennai City

A study was carried out to assess the chromium content of groundwater in the vicinity of tanneries in a district of Chennai, southern India. The common effluent treatment plant (CETP) treats the sewage from these tanneries before releasing it into open drains that connect to the neighbouring Adyar River. Tanneries are one of the industries that significantly contribute to pollution in the Chennai district. Chennai, the study region famous for having an airport in the district, is a rapidly urbanising area. There are many tanneries in the vicinity, and their effluents frequently impact the nearby land and water since they are not treated. The chemicals that lead to the area’s degradation have been identified by chemical analysis of the collected water samples.

“Flood inundation mapping of upstream region in the Adyar River basin: Integrating hydrologic engineering centre's river analysis system (HEC-RAS) approach with groundwater considerations”

Chennai, the capital of Tamil Nadu, has grappled with recurrent devastating floods, notably in 2015 and 2021, originating from the upstream of the Adyar River basin. These events have profoundly impacted the city's growth sectors. The regions both upstream and downstream of the Adyar basin, covering Chennai and Chengalpattu districts, face increased vulnerability to severe riverine flooding due to rapid urbanization. The interplay of extensive urban development and river overflow during monsoon seasons has created conditions conducive to substantial flooding, necessitating the development of an effective flood model. This study utilizes digital elevation data and unit hydrograph analysis to estimate flood return probability water levels for various recurrence intervals, including the 10-year and 100-year events. Moreover, it investigates flood inundation, specifically in the Somangalam area, providing insights into the extent of water spread. To comprehensively address the flood dynamics, the study incorporates considerations for groundwater interactions. The overarching objective remains to identify the most vulnerable zones within the Adyar River region prone to flooding. Accurate identification of these vulnerable areas is crucial for policymakers and stakeholders to devise proactive planning and early warning measures, enhancing disaster preparedness and resilience in the face of potential flood disasters. This approach aims to safeguard the well-being of Chennai's residents and promote sustainable development in the region.

Air-water exchange and risk assessment of phthalic acid esters during the early phase of COVID-19 pandemic in tropical riverine catchments of India

Given the increased load of waste plastic in the solid waste stream after the outbreak of the COVID-19 pandemic, we investigated the fate of selected plastic additives along open burning dumps, industrial and residential transects in tropical riverine catchments of India. Polyurethane foam disk passive air samples, surface water and community stored water (CSW) samples were collected along the Adyar River (AR), Cooum River (CR) and canals in Chennai and Daman Ganga River (DG) in Vapi. Among the quantified phthalic acid esters (PAEs), a widely used plastic additive, di(2-ethylhexyl) phthalate (DEHP), was ubiquitous across all the transects. More open drains and leaching of littered single-use plastic items can be the reason for significantly higher (p < 0.05) levels of PAEs in CR over other rivers with a dominance of di-n-butyl phthalate (DnBP). Prevalence of open burning of dumped plastic waste was the possible primary emission source of PAEs in these riverine catchments. Excluding highly soluble dimethyl phthalate (DMP), air-water exchange processes reflected the secondary emission of all the PAEs from the surface water along the open burning sites. Despite the cleansing effect of the oceanic air mass from the Bay of Bengal and the Indian Ocean, the average atmospheric PAE level was two-fold higher in Chennai than Vapi. Even though Vapi is a coastal city along the Arabian Sea, it was impacted by inland air masses during the sampling event. Open burning dumpsites showed a five-fold increase in atmospheric priority PAEs in Chennai city after the outbreak of the COVID-19 pandemic. DnBP was the major contributor to estrogenicity in CSW and DG, and also posed maximum risk for fishes in the open burning transect of these tropical rivers.

Bioaccumulation of Titanium in diatom Cyclotella atomus Hust.

Diatomaceous earth or diatomite is a fossil rock deposit of diatoms made up of silica and other minerals. A distinguishing feature of diatoms that placed them in the single class of microalgae Bacillariophyceae, is the frustule, a transparent, hard-shelled cell wall. It's interesting to note that the diatom has specific proteins and enzymes for heavy metal detoxification and can intake and store more heavy metals in its frustule. Consequently, an attempt has been made in this study to determine the bioaccumulation of metals in the frustules of the diatom. Hence, a centric diatom was isolated from the freshwater sample collected from the Adyar River, Chennai, Tamil Nadu. The diameter of the cell was 5-7.5µm and 20-23 striations with radial arrangement. A single, dark off-center fultoportula and marginal fultoportula on the striae are found in the diatom. Additionally, one rimoportula between two marginal fultoportula distributed on the striae between the costa was also seen. As a result, the isolated diatom was morphologically identified as Cyclotella atomus Hust. Simultaneously, the bioaccumulation study reveals that the Titanium (Ti) was found accumulated in the frustules of the diatom incubated in the Ti-supplemented culture medium based on the scanning electron microscope-energy-dispersive X-ray analysis (SEM-EDAX). Therefore, the biogenic accumulation and fabrication of Titanium frustules in diatom have advantages in enhancing the efficiency of solar cells.

Mapping and assessing spatial extent of floods from multitemporal synthetic aperture radar images: a case study over Adyar watershed, India.

Urban floods are more concerned in recent days due to their substantial effect in loss of human lives and properties. Due to climate change, urban floods are frequently observed in many parts of the world. Flood events in Chennai city are a frequent scenario due to rapid increase in the density of population. Adyar river watershed and surrounding urban cover are focused in the present study. The present study aims at mapping flooded region using Sentinel 1A datasets over Adyar watershed. Series of Sentinel 1A image is collected before, during and after floods for mapping the extent of flood and mapping risk zones in Adyar watershed. Methodologies such as ISODATA Technique, Multi-Temporal Analysis, Thresholding Method, PCA and ICA Analysis and Grey Level Co-Occurrence Matrix are adopted for the extraction of flooded extent from the SAR datasets. Analysis performed over the Adyar watershed provided promising results in the extraction of flooded extent with Thresholding Method and Grey Level Co-Occurrence Matrix being the dominant of all the methods. Though higher accuracy is obtained in the extraction of flooded extent, limitation of layover, foreshortening and shadow is experienced in the built up region for the extraction of flooded pixels.

Legacy and new chlorinated persistent organic pollutants in the rivers of south India: Occurrences, sources, variations before and after the outbreak of the COVID-19 pandemic

During pre-pandemic time, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the surface water of Periyar River (PR) and Bharathappuzha River (BR) in Ernakulam and Malappuram districts of Kerala, respectively and Adyar River (AR) and Cooum River (CR) in Chennai district of Tamil Nadu. After the outbreak of COVID-19 pandemic, variation in OCPs and PCBs were evaluated for AR and CR. Dominance of β-HCH and γ-HCH in south Indian rivers indicate historical use of technical HCH and ongoing use of Lindane, respectively. In > 90 % sites, p,p′-DDT/ p,p′-DDE ratio was < 1, indicating past DDT usage. However during the outbreak of the COVID-19 pandemic, elevated p,p′-DDT in AR and CR reflects localized use of DDT possibly for vector control. Similarly, during the first wave of pandemic, over a 100-fold increase in PCB−52 in these rivers of Chennai mostly via surface run-off and atmospheric deposition can be reasoned with open burning of dumped waste including added waste plastic in the solid waste stream. On contrary, a significant (p < 0.05) decline of dioxin-like PCBs level, suggests lesser combustion related activities by the formal and informal industrial sectors after the lockdown phase in Tamil Nadu. Eco-toxicological risk assessment indicated a higher risk for edible fish in PR due to endosulfan.

A mathematical approach to groundwater quality and pollution of Adyar sub-basin, Tamil Nadu, India

The quality of drinking water sources in the Adyar river sub-basin of northern Tamil Nadu is assessed in this study. This research uses a combined water quality index (WQI) and pollution index (PI) to assess and characterise groundwater quality. Water samples will be collected from nine locations in the study area for the assessment. The water quality index was calculated based on Total Dissolved Substances (TDS), Nitrogen oxides (NOx), Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), Chloride (Cl), Sulphate (SO4), Bicarbonate (HCO3), Fluoride (F), Power of Hydrogen (pH) and Electrical Conductivity (EC). These twelve parameters were analysed and characterised according to standard methods and the Indian standard, which were then used in calculating the water quality index. Groundwater quality and pollution status of the Adyar river basin were assessed using the Groundwater quality index and comprehensive pollution index for the years 1990, 2005, and 2020. A result reveals that the groundwater quality has decreased from 1990 to 2020. Around seven parameters exceeded the permissible limits in 1990, nine parameters exceeded the permissible limits in 2005, and around eight parameters exceeded the allowable limits in 2020. The pollution status of the groundwater has considerably reduced from 1990 to 2020. Eastern parts of the study area were highly polluted and had low groundwater quality.

Baseline Study on Microplastics in Indian Rivers under Different Anthropogenic Influences

Microplastic particles are found in environmental compartments all over the world and receive a great deal of attention, especially in the aquatic environment. Currently, a particularly high input of microplastics via Asian rivers is assumed, but so far, there are hardly any data through field measurements. Three rivers in South India were considered for this purpose to focus on their microplastic load. The emphasis was on the comparison of microplastic concentrations in urban and rural rivers. While two rivers in the megacity Chennai (Tamil Nadu) were found to have an average microplastic concentration of 0.4 microplastic particles/L, a rural river near Munnar (Kerala) had an average concentration of 0.2 microplastic particles/L. Rough estimates of annual microplastic discharge from the Adyar River (Chennai) into the Bay of Bengal are found to be as high as 11.6 trillion microplastic particles. This study should be one of the first baseline studies for microplastic loads in South Indian streams and should be complemented with further environmental sampling before, during and after the monsoon season to get more detailed information on the storage and transportation of fluvial microplastics under different weather conditions.

Analysis of shoreline change between inlets along the coast of Chennai, India

Chennai is a major metropolitan city along the southeast coast of India and is popular for its world’s second longest sandy beach called as Marina beach the shoreline of which has been gradually advancing towards the Bay of Bengal over a century. The advance of the shoreline is due to the construction of breakwaters for the formation of the harbor of Chennai port, one of the 12 major ports of India. The study area is the stretch of the shoreline between two zones, viz., Zone I: Cooum (13° 4′ N and 80° 17′ 20″ E) and Zone II: Adyar (13° 0′ 49″ N and 80° 16′ 38″ E). The rate of shoreline change over the period 2000 to 2019 is analysed through statistical parameters using geographical information system and DSAS (digital shoreline analysis system) in the form of erosion and accretion. The LRR results elucidate that the Chennai coast has experienced an extremely dynamic feature with an average erosion rate of −1.67 m/year. The accretion due to the littoral drift with an average rate of +1.31 m/year is driven by the net alongshore current towards the north of the Adyar River.

Quality assessment of ground water along the banks of Adyar river using GIS

Ground water is a vital natural resource essential for human-health, socioeconomic development and functioning of ecosystem.The pollution of river bodies is a major problem in India, because of inadequacy / non -existence of ground water quality protection measures. Adyar river contributes to the demands of this big Chennai city's primary supply. The quality check of groundwater becomes important to adopt various preventionalactions.This work was taken out to compute the effect of impact of Adyar river water in the ground water quality. pH in groundwater of the study area were incarcerated the acme healthy limits of WHO standards. The values of Electrical conductivity was more than permissible limit and show high impact near the coast and were not permissible for drinking. Due to the discharge of effluents from industry and residentials, the ionic concentration of ground water towards the eastern part is high. Intrusion of seawater is the cause for the chloride dominant groundwater near the coast. Using ArcGis 9.4 version, the distribution of parameters and water quality indexwere mapped spatially for the study area.

Architecting neonicotinoid-scavenging nanocomposite hydrogels for environmental remediation

The ubiquitous presence of neonicotinoid insecticides in the environment poses potential health concerns across all biomes, aquatic systems, and food chains. This global environmental challenge requires robust, advanced materials to efficiently scavenge and remove these harmful neonicotinoids. In this work, we engineered nanocomposite hydrogels based on sustainable cellulose acetate for water treatment. The nanocomposite hydrogels were incorporated with small quantities of polymers of intrinsic microporosity (PIM-1) and graphene oxide (GO). We prepared the hydrogels using green solvents such as Cyrene and MeTHF via simple dropwise phase inversion. High adsorption capacity and fast kinetic behavior toward acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam were observed. We also developed a rapid and sustainable ultrasound-assisted regeneration method for the hydrogels. Molecular dynamics of the complex quaternary system revealed the synergistic effects of the components, and the presence of PIM-1 was found to increase the GO surface area available for neonicotinoid scavenging. We demonstrated the robustness and practicality of the nanocomposites in continuous environmental remediation by using the hydrogels to treat contaminated groundwater from the Adyar river in India. The presented methodology is adaptable to other contaminants in both aqueous environments and organic media.

Investigation of Role of Retention Storage in Tanks (Small Water Bodies) on Future Urban Flooding: A Case Study of Chennai City, India

The Adyar River flowing through Chennai Metropolitan Area (CMA) in Southern India functions as a surplus course of upstream water bodies that are locally known as tanks. During northeast monsoons, the river frequently floods the adjoining city areas. In this study, the impact of dredging and disappearance of tanks on flooding in CMA is analyzed under historical, urbanization, and extreme rainfall scenarios utilizing an urbanization-hydrologic-hydraulic modelling framework. The simulated scenarios highlight the importance of the tanks as a flood control measure for CMA. The major conclusions are (a) dredging the tanks uniformly by 2 m can compensate the increase in flooding due to urbanization by 2050 for 1 in 50-year rainfalls and, (b) for disappearance of tanks, 1 in 50-year rainfall can inundate the city akin to 1 in 100-year rainfalls. The study can be useful for making informed decisions on dredging the tanks, land use planning, and flood control measures for the CMA.

RETRACTED ARTICLE: Comparative analysis of spatial interpolation with climatic changes using inverse distance method

An ecological change on the planet the most flighty parameter is precipitation. It causes minor and real changes in the climatic changes. The time and space analyzed on the data and the spatial and temporal patterns are introduced in the required manner. For the unpredictable data to be predicted by using the spatial interpolation techniques. The major spatial interpolation methods are categorized based on the simple and complex mathematical modeling. Those studies involve interpolation techniques such as ordinary Krigging, inverse distance weighted (IDW), Spline, etc., Most of the techniques studied the hydrological modeling and deliver hydro mapping (Younghun Jung and Venkatesh Merwade 2015). Various techniques are used for the hydrological mapping. This study involved comparing the statistical interpolation with precipitation and temperature. The cumulative values in the dataset taken from the year 2001 to the year 2013 used in the study. The monthly and the yearly mean square value calculated using the spatial interpolation techniques (Dhamodarn and Shruthi 2016). The main objective of the study is to find the topographical features and provides high-resolution climate maps using mathematical modeling. In the result of comparing the above interpolation methods in the result will produce the high-resolution climate maps and generate the geographical patterns. Based on the study will produce climate change in the environment like disaster, flood, landslide. The comparative study of interpolation methods and mean variation can be resulted and used for the further implementation of spatial climatic condition and decision support system to the society. The area has undergone the study is Adyar river, situated in latitude 13.0012° N, Longitude 80.2565° E. Inverse Distance Weighted interpolation methods are analyzed by using the Geostatistical tool ArcGIS.

Evaluation of potable groundwater zones identification based on WQI and GIS techniques in Adyar River basin, Chennai, Tamilnadu, India

The main objective of this study is to identify the potable groundwater zones in Adyar River Basin (ARB) that forms the major river of Chennai metropolitan and significantly contributes to the demands of this big city's water supply. Twenty eight groundwater samples were collected during postmonsoon and premonsoon seasons in 2016 from the wells of ARB which is downstream of Chembarambakkam Lake, which supplies drinking water to Chennai metropolitan city. All the water samples were analyzed using Portable meter and Ion Chromatography for physico-chemical parameters and major ions such as pH, TDS, Ca, Mg, Na, K, Cl, HCO3, SO4 and NO3. The analytical results were compared with the WHO, USEPA & BIS guideline values and reported that some of the samples exceeds these guideline values for drinking water quality. Spatial distribution maps were prepared to identify the potable groundwater available regions based on these water quality parameters. Piper and Gibbs plots are generated to identify the nature and type of groundwater with processes controls the groundwater chemistry. Principal component analysis was done to interpret the possible sources of chemical compounds present in the groundwater. To precisely delineate the potable groundwater region in ARB, Water Quality Index (WQI) approach is employed with the basic water quality parameters and spatial distribution maps were prepared using GIS for the obtained indexes. It is found that only 10.71% and 17.86% of the study area groundwater is within the excellent water quality for drinking during postmonsoon and premonsoon respectively, whereas 42.86% in postmonsoon and 14.29% in premonsoon is found as poor quality groundwater for drinking. The groundwater of the northwestern and western part of ARB is under very poor and unsuitable category for drinking in both the seasons. This region of ARB is recommended for implementation of artificial groundwater recharging to improve the groundwater quality and make it suitable for drinking.

Hydrological Simulation for Predicting the Future Water Quality of Adyar River, Chennai, India.

Just a few decades ago, Adyar River in India’s city of Chennai was an important source of water for various uses. Due to local and global changes (e.g., population growth and climate change), its ecosystem and overall water quality, including its aesthetic value, has deteriorated, and the water has become unsuitable for commercial uses. Adverse impacts of excessive population and changing climate are expected to continue in the future. Thus, this study focused on predicting the future water quality of the Adyar river under “business as usual” (BAU) and “suitable with measures” scenarios. The water evaluation and planning (WEAP) simulation tool was used for this study. Water quality simulation along a 19 km stretch of the Adyar River, from downstream of the Chembarambakkam to Adyar (Bay of Bengal) was carried out. In this analysis, clear indication of further deterioration of Adyar water quality by 2030 under the BAU scenario was evidenced. This would be rendering the river unsuitable for many aquatic species. Due to both climate change (i.e., increased temperature and precipitation) and population growth, the WEAP model results indicated that by 2030, biochemical oxygen demand (BOD) and Escherichia coli concentrations will increase by 26.7% and 8.3%, respectively. On the other hand, under the scenario with measures being taken, which assumes that “all wastewater generated locally will be collected and treated in WWTP with a capacity of 886 million liter per day (MLD),” the river water quality is expected to significantly improve by 2030. Specifically, the model results showed largely reduced concentrations of BOD and E. coli, respectively, to the tune of 74.2% and 98.4% compared to the BAU scenario. However, even under the scenario with measures being taken, water quality remains a concern, especially in the downstream area, when compared with class B (fishable surface water quality desirable by the national government). These results indicate that the current management policies and near future water resources management plan (i.e., the scenario including mitigating measures) are not adequate to check pollution levels to within the desirable limits. Thus, there is a need for transdisciplinary research into how the water quality can be further improved (e.g., through ecosystem restoration or river rehabilitation).

Numerical Modelling of Adyar River

Many parts of our country are subjected to frequent flooding every year during the annual monsoon rains from June to September. South India is especially affected by the north east monsoon. November month of 2015 has been the wettest month in the history over a century. First December 2015 has experienced a maximum rainfall of 490mm which is the highest value in the last century. This flood as served as a wakeup call for India to grow. This study is to do the numerical modelling of Adyar River with the help of HEC-RAS software by analysing the statistical data of rainfall for the past 40 years and to find the monsoonal and yearly variations of rainfall and also to analyse the cross section of Adyar river. Gumbel distribution is used for computing the extreme values of rainfall for a given period of time. The water surface profile of Adyar River from the Nandambakkam to Adyar Creek is then modelled and conclusions were drawn.

Environmental impact assessment of surface water and groundwater quality due to flood hazard in Adyar River Bank

A study was conducted in Metro cities in Chennai handling Water quality problems due to increasing population and improper disposal of solid and liquid wastes. The research work carried out in Adyar River Basin (ARB) this river adjoining from both Chennai and Kanchipuram district, Tamilnadu. The main objective of the present study is to identify the processes controlling the geochemistry of surface water and groundwater due to impact of flood in Adyar River. Surface water and groundwater samples collected from either side of the river were analyzed during post-monsoon and pre-monsoon (2016) adopting the standard methods of (WHO). Dominance of cations are in the following order Ca > Na > Mg > K and anions Cl > HCO3 > SO4 during the study period. The analytical results shows higher concentration of TDS, EC, Na, Cl, which indicate signs of deterioration but in the values of pH, Ca and Mg, are within permissible limit as per standards. To understand the geochemical processes piper and gibbs plot has used for the study. Rock water interaction and anthropogenic processes were the major processes controlling groundwater chemistry in this area.