Ramani Huria began mapping Tabata ward on 7th October and completed mapping on 6th November 2015. Tabata is an administrative ward in Ilala district in western Dar Es Salaam and according to the 2012 census has a population of 46,228.
apping was launched in the ward with an opening community forum, taking place at the ward office, and attendance included: Tabata Ward Executive Officer (WEO); eight Mtaa Executive Officers (MEOs), five Mtaa chairmen; eight community members; and representatives from the Ramani Huria team.
Active mapping started on 12th October with data collection and relevant information for the mapping process was collected from the field using GPS units and attribute tables. Data collected including information relating to buildings, roads, waterways, and points of interest, and this was digitalized using JOSM software.
In the process of mapping, the mappers observed a number of issues relating to the effects of flooding. One of the goals of Ramani Huria is that data we collect can be used to improve flood resilience at a local level.
Observing Flooding in Tabata
The city of Dar es Salaam is affected by seasonal flooding, with some wards being more severely hit and for a variety of reasons. Our mappers include community members who are able to provide first-hand information about the features of the ward, and how each ward is specifically affected by flooding.
In Tabata, housing construction has a severe impact on the scale of flooding. In sub-wards Tabata Muslim and Tabata Aroma, there are buildings constructed across a stream that collects water from the road’s drains. Due to this, only a small amount of water can flow, and in the rainy season the large volumes of water cannot flow sufficiently. As a result, flooding occurs, specifically affecting the residential buildings.
Small scale sand mining activities take place in the Msimbazi River valley, bordering the east and southern parts of the ward, and have resulted in the widening of the river valley. As a result of this, the effects of flooding has increased, specifically affecting residents and properties in Magharibi sub-ward.
We observed the buildup of waste in the streams, drains, and ditches of the ward. Poor organisation of waste disposal and maintenance of drains are therefore additional factors that increase the severity of floods. As waste builds up in the streams, drains, and ditches, the flow of water is restricted and cannot flow out of the ward and causes flooding during the rainy season.
The effect of flooding in Tabata
Due to annual flooding, soil deposits build up around buildings, resulting in the appearance of their height being reduced. The buildup of deposits also increases the ease of water to enter the building and so causing them to be more severely affected each year.
During flooding, many residents and businesses move property out from within buildings, in the hope of avoiding further water damage if the building is already flooded or at risk of flooding. This is extremely inconvenient and can be costly, both due to transportation and interruption to work and daily life. The sub-wards of Msimbazi Magharibi, Msimbazi Mashariki, Tenge and Matumbi, are especially affected in this way.
In severe cases, properties may be completely destroyed as a result of flooding. We observed this occurring in Msimbazi Magharibi and Mashariki sub-wards, along the Msimbazi River valley. Due to flooding buildings may be abandoned, as they also become dangerous to occupy, and over time may become even more worn down, resulting in demolition being the only option.
Actions taking place to reduce the effects of flooding in Tabata
Changes are being made in construction, with many buildings now being raised with the aim of reducing the effects of flooding. Residential buildings, kitchens, and toilets are also being elevated to raise them above flood lines of previous years.
Presenting maps to Tabata community
Closing community forums were held in Tabata ward on 27th of November, with maps being presented to the Ward Officer and ward community. The experiences of mapping were discussed among those in attendance, specifically how these resources can help improve flood resilience within the ward. Additionally, certificates were presented to students and community members who assisted in the mapping process.
[osm_map_v3 map_center=”-6.815,39.222″ zoom=”16″ width=”100%” height=”450″ ]
Current map of Tabata ward, following mapping by Ramani Huria
All data collected through Ramani Huria is freely available online and through OpenStreetMap. In addition to a general map, we have also created a drainage map. You can read more about how we are mapping drainage on our blog.