Friday, 22 July 2011

Winter rains soak wetland park

Scenes like this dominate the Western Shores landscape in the iSimangaliso Wetland Park after heavy rains last week

Four days of pelting rain last week turned iSimangaliso Wetland Park streams into torrents and have significantly raised the level of Lake St Lucia. In what has been described as the best downpours in many years, there is standing water as far as the eye can see. iSimangaliso CEO, Andrew Zaloumis reported the following rainfall figures for the 72 hours ending 8am on Sunday:
•Manzengwenya - 89mm
•False Bay - 53mm
•Charters Creek - 103mm
•St Lucia - 135mm
•Mission Rocks - 168mm
•uMkhuze - 2mm

‘Eye-balling Catalina Bay, I would estimate the lake has risen 150mm,’ said Zaloumis. ‘At St Lucia a total of 1430.6mm of rain was measured in the nine months from the start of October 2010 to the end of June 2011. ‘The overcast weather and frequent rainy days reduced evaporation losses over this period. ‘Lake St Lucia can lose about a billion litres of fresh water across its 30 000ha surface to evaporation on a hot windy day,’ said Zaloumis. ‘About 100 000 cubic metres of fresh water from the Mfolozi is now flowing into the St Lucia estuary each day. ‘This water enters the Narrows of the estuary via a channel excavated many years ago and through which relatively silt-free water flows when the Umfolozi mouth is closed. ‘This inflow of fresh water has lessened the impact of the ongoing drought conditions.’ As a result of the good rains, the salinity (or salt content of water) has been significantly lowered in the lake. For example, at Charter’s Creek in January the salinity of lake water dropped from 55ppt to10 ppt and has remained reasonably low since then.

Not the coldest Winter
Southern Zululand did not receive much rain last week, with Mandeni recording 15mm, Mthunzini 19mm and Richards Bay 9mm. Ulundi has received no rain over the last 10 day period but last month there were good winter rains along the southern coast with Gingindlovu measuring 58.8mm and Empangeni 31.8mm. eShowe recorded 29.2mm while only 20km inland, 43.4mm was measured at Entumeni. Many residents are reporting this Winter as the coldest in years. The Durban weather office says that residents are feeling the cold, mainly due to the rain and unseasonal biting winds which has dropped the ambient temperature with cold ‘chill factors’. The temperature has however not dropped to the low levels of the mid 80s, when large indigenous trees in the Dukuduku Forest died of frost.