B Banjarmasin city is known as the “city of a thousand rivers” due to its numerous rivers, which constitute an integral part of the community’s life and serve important functions as transportation routes, flood control infrastructure, and an element of the city’s identity. however, buildings are still found within river setback areas, resulting in the impairment of the function of river setbacks as buffer zones and protected areas for maintaining river functions. in response to these conditions, the government of banjarmasin city enacted regional regulation of banjarmasin city number 15 of 2016 concerning efforts to improve river management. the department of public works and spatial planning of banjarmasin city, as a regional apparatus responsible for administering governmental affairs in the fields of public works and spatial planning, has authority in the implementation of river management. this research examines the authority of the department of public works and spatial planning in river management, as well as the obstacles encountered and the efforts undertaken in its implementation. this research constitutes normative legal research with a descriptive-analytical approach, utilizing secondary data as the primary source and primary data as supporting data. the data were analyzed qualitatively, and conclusions were drawn using a deductive method. the results of the research indicate that the implementation of river management, encompassing planning, development, utilization, and maintenance, has not been carried out optimally due to limitations in human resources and budgetary resources, inadequate coordination among regional government agencies, and low levels of public awareness. therefore, improved inter-agency coordination, law enforcement, and active community participation are necessary to optimize river management in banjarmasin city.