Wetlands are crucial for the environment and offer numerous ecosystem services. These enhance living conditions in urban and periurban areas by sequestering carbon, providing wildlife habitats and mitigating urban heat islands. Urban wetlands face significant challenges like hydrological functions, wastewater contamination, habitat loss from land-use changes, biodiversity loss from invasive species, habitat alteration, and changes in water quality, among other reasons. In most urban wetlands there has been a notable lack of long-term biodiversity monitoring data. Bangalore, one of India’s most rapidly developing cities, faces significant threats to its wetlands, with few systematic studies on the status of biodiversity in and around these ecosystems. This study aims to understand the status of systematic biodiversity documentation in wetlands of urban and periurban Bangalore. Further, I systematically documented the biodiversity at Maralawadi Dam, one of the periurban wetlands within the Ramanagara district. Using this baseline data, I created a comprehensive field guide wetland fauna of the Maralwadi dam which will help in future conservation efforts and understanding of biodiversity in these areas. This study emphasizes the need for detailed documentation and long-term follow-up to preserve urban and periurban wetland ecosystems.