Flowing through the City: Urban Streams and Green infrastructure networks

Context and Background Urban streams play a significant role in sustaining ecosystem services vital to city dwellers’ life. However, there is a notable lack of comprehensive understanding of their characteristics, spatial connectivity to other urban green infrastructure elements, status of water flow, and their uses in Sub-Saharan African cities.  In filling this gap, this paper examined urban streams and their connection to other urban green infrastructure elements. Goal and objectives The overall objective of this study is to examine the nature, connectivity, uses and ecosystem disservices of urban streams in relation to other urban green infrastructure in Dodoma City. Specific objectives are: To examine the nature of urban streams in the study area; To assess connectivity of urban streams with other green infrastructure; To explore uses of urban streams; and To determine ecosystem disservices emanating from urban streams before presenting conclusion and recommendations. Methodology A mixed research approach was used to collect both quantitative and qualitative data whereby a random sample of 423 households were interviewed. Data collection methods involved household interview, Focus Group Discussions, observation and document review. Statistical Package for Social Science and Microsoft excel were employed to perform descriptive analysis whereby thematic analysis was used to analyse qualitative data from key informants while Arc GIS Software was employed to spatially determine the extent of encroachment into urban streams. However, the urban landscape ecological theory through the patch-corridor-matrix model provided the necessary lens to analyse how urban streams are connected to other urban green infrastructure. Results Originating from nearby hills, built up areas and wetlands urban streams exhibit intermittent, ephemeral and few year round water flow. Moreover, urban streams are connected to other urban green infrastructures resulting into spatial, hydrographic and social connectivity. Dams along the course of the stream play significant role in storing large volumes of water, and improve peak flow reduction during heavy rains. Urban streams are useful in providing water for various uses, but also helps to convey storm water away from residential areas. The study further revealed that despite uses, urban streams are characterized by ecosystem disservices. The study underscores the need to enhance governance of urban streams so as to improve city resilience against ecosystem disservices but also to continue providing useful ecosystem services.