Change in water supply and drainage patterns of surface and subsurface moisture zones are greatly enhanced due to anthropogenic activities. Monitoring changing wetland ecosystems helps to determine their tolerance to such anthropogenic activities. Sultanpur National Park, a wetland ecosystem located in Gurgaon district of Haryana state is such an ecosystem, harbouring plant and animal biodiversity. Increase in agriculture and builtup area in the surrounding region along with artificial deepening of the lake area for rainwater accumulation has led to the degradation of the central lake both in terms of quantity and quality. The anthropogenic influence was validated by landuse landcover mapping (through K-means unsupervised classification) of LANDSAT data within the wetland catchment for year 2000 and 2015 having an overall accuracy of 89.45% for 2000 and 80.48% for 2015. A declining trend in the total area under water cover in postmonsoon with a final area reduction of ~66% was observed from the year 1995–2015. Rampant agriculture and builtup land adjacent to the lake as well as artificial pumping of groundwater are major reasons for the deterioration of the lake water quality further posing major threats to the wetland ecosystem. Siltation from erosion and surface runoff due to mining and agriculture have led to the input of ionic components resulting in lake water quality deterioration as well as reduction in the depth of the lake available for rainwater accumulation. It has been inferred that high concentrations of nitrate (50% of samples above permissible limit (> 45 ppm)) and phosphate (50% of samples above permissible limit (> 0.1 ppm)) ions within the lake water is due to input from surface run off from the surrounding agricultural cropland within the lake catchment further leading to lake eutrophication and habitat loss suitable for plant and animal biodiversity.