Blocked culverts may have caused flood

BLOCKED culverts in Pionierspark Extension 1 may have contributed to the flooding of the Arebbusch River near the Acacia area last Friday, causing damage to a number of properties.

Ongoing hydrological surveys by the Department of Water Affairs this week have revealed that the water in a channel running from Pionierspark Extension 1 to Tauben Glen, where it meets the Arebbusch River, was obstructed and this might have caused water to dam up along the way and flood the river. The Namibian yesterday followed the course of the water flow with Deputy Director of Hydrology Guido van Langenhove and saw that culverts under Scheppmann Road near the Windhoek International School prohibited the free flow of water overflowing from the Van Rhijn Dam.The Van Rhijn Dam lies in a channel running between houses in Pionierspark.Here the overflow caused damage to property in the Eagle Rock complex on one side of the channel.As the water flowed down the channel towards Scheppmann Street, it appears that water and debris dammed up at the three blocked culverts beneath the road, all of which had grates in front of them.Eventually the water did manage to break through the grates and cut a path through the large mound of sand that blocked one of the culverts on one end.The watermarks where the blockages were breached are still visible at this point.It is unclear why these culverts had grates in front of them – presumably to prevent public access to the Van Rhijn Dam.Further down the channel near Concordia College, the wave of water met another obstacle – a huge sand embankment and a fence.This swell of water met an already raging Arebbusch River in Hochland Park.According to Van Langenhove, depending on the exact timing, this might have contributed to the flood further downriver in Acacia.In Acacia, the river passed by houses it flooded two years ago, just making its way under the bridge entering the development where concrete walls protect the houses.But as the river narrowed around a bend lower down, it burst its banks, knocking down pre-cast walls and entering more than 30 properties.In more than half of these cases, the water went right through people’s homes.The hydrology department is still working on estimated values for the flows after measuring the flood lines in certain areas yesterday.However, Van Langenhove stands by his observations earlier this week, that Friday’s flood was less severe than that of 2004.Flood marks at the bridge in Moses Garoeb Street just downstream from Acacia have already proven to be lower than those of two years ago.It is yet to be determined whether these findings are consistent with those of the Windhoek Municipality.City Spokesperson Liz Sibindi said yesterday the City would only complete its assessment of the floods and the damages next week, when all staff are back in office.The Namibian yesterday followed the course of the water flow with Deputy Director of Hydrology Guido van Langenhove and saw that culverts under Scheppmann Road near the Windhoek International School prohibited the free flow of water overflowing from the Van Rhijn Dam.The Van Rhijn Dam lies in a channel running between houses in Pionierspark.Here the overflow caused damage to property in the Eagle Rock complex on one side of the channel.As the water flowed down the channel towards Scheppmann Street, it appears that water and debris dammed up at the three blocked culverts beneath the road, all of which had grates in front of them.Eventually the water did manage to break through the grates and cut a path through the large mound of sand that blocked one of the culverts on one end.The watermarks where the blockages were breached are still visible at this point.It is unclear why these culverts had grates in front of them – presumably to prevent public access to the Van Rhijn Dam.Further down the channel near Concordia College, the wave of water met another obstacle – a huge sand embankment and a fence.This swell of water met an already raging Arebbusch River in Hochland Park.According to Van Langenhove, depending on the exact timing, this might have contributed to the flood further downriver in Acacia.In Acacia, the river passed by houses it flooded two years ago, just making its way under the bridge entering the development where concrete walls protect the houses.But as the river narrowed around a bend lower down, it burst its banks, knocking down pre-cast walls and entering more than 30 properties.In more than half of these cases, the water went right through people’s homes.The hydrology department is still working on estimated values for the flows after measuring the flood lines in certain areas yesterday.However, Van Langenhove stands by his observations earlier this week, that Friday’s flood was less severe than that of 2004.Flood marks at the bridge in Moses Garoeb Street just downstream from Acacia have already proven to be lower than those of two years ago.It is yet to be determined whether these findings are consistent with those of the Windhoek Municipality.City Spokesperson Liz Sibindi said yesterday the City would only complete its assessment of the floods and the damages next week, when all staff are back in office.