Urbanization is a major global development. At present, more than half of the world population lives in urban areas, i.e., cities. One of the fundamental requirements of citizens is safe and sufficient drinking water. The premises for water security are adequate water management and governance. In this study, we determine priorities for Integrated Water Resources Management (IWRM) and assess the governance capacities of different organizations to address IWRM in Ulaanbaatar, the capital of the landlocked Asian country Mongolia. We apply the City Blueprint Approach (CBA), a diagnosis tool, to assess IWRM in Ulaanbaatar city, Mongolia. The overall score, the Blue City Index (BCI), is 2.3 points for Ulaanbaatar, which categorizes the city as wasteful. Flood risk and economic pressure have a great impact on the water sector in Ulaanbaatar city. In particular, Ulaanbaatar’s waste water treatment (WWT) can be improved. Often, only primary and a small portion of secondary WWT is applied, leading to large-scale pollution. Water consumption and infrastructure leakages are high due to the lack of environmental awareness and infrastructure maintenance. Operation cost recovery is not sufficient to sustain urban water services in Ulaanbaatar. Water governance and more specifically monitoring, evaluation and statutory compliance are among the factors that need to be addressed.

This is the first seasonal observation study on nutrient dynamics undertaken in a small freshwater lake with eutrophication in Mongolia. The vertical profile and seasonal fluctuation of nutrients are crucial to understanding the biogeochemical cycles in aquatic systems. In this study, field research was carried out at a small and shallow lake, Lake Bulan, in the lower Kharaa River basin. The area has been receiving increased nutrient loads from the water catchment area for the last 20 years. Water samples were collected seasonally from the lake from 2019–2022 and analyzed for nutrients, major cations, trace metals, and dissolved organic carbon. The average concentration of dissolved inorganic nitrogen (DIN) in the surface lake water had a wide seasonal variation from 0.26 ± 0.11 mg N/L in August to 1.44 ± 0.08 mg N/L in January. Seasonal differences were also observed in the vertical profiles. Concentrations were relatively similar at the various water depths in April and September at turnover time. Thermal stratification was observed when the lake was covered in ice, with the maximum concentrations being observed in the bottom layer in the months of January and August. The phosphate concentration showed a similar variation trend. These results indicate that both the summer and winter stratifications are important for regeneration of nutrients in the bottom layer, biochemical cycling, and mitigating impacts of global warming on small and shallow lakes in Mongolia.