Heavy falls of rain are expected in the Overberberg, southern parts of the Cape Winelands and western parts of the Eden District on Friday, spreading into the eastern parts of the Eden District on Saturday.
Heavy rainfall raises the water level. When the water level is higher than the river banks or the dams, water comes out from the river and flooding occurs.
Preventive measures:
- Construct proper drainage system – Shallow drains due to silts must be cleaned constantly as they ensure proper water irrigation.
- Increased evaporative losses, mechanical land treatment of slopes, such as contour ploughing or terracing, to reduce the runoff coefficient.
- Construction of small water and sediment holding areas.
- The construction of floodways (man-made channels to divert floodwater).
- Terrace hillsides to slow flow downhill.
What to do when heavy rainfall is forecast:
- Avoid cutting grass in the rainy season (nutrient depletion).
- Avoid applying fungicides and pesticide (plants and animals).
- Avoid applying N fertiliser (burning of plants) (Nitrogen loss is higher during heavy rain), immediately follows a surface application of fertilizer, especially on sloped areas.
- Dumping fertilizer in one spot can cause the roots below the fertilizer to be burned and die).
- Avoid irrigating (waterlogging can occur, nutrient depletion).
- Cover Urea licks to prevent them from becoming toxic.
- Provide shelter for animals (young ones die easily).
- Leave cultivated areas coarse.
- Relocate/ Move animals to a safe place.
The following are a number of concerns and recommendations:
- Be extra cautious and look for pests and diseases after rain has fallen, as high moisture content and the high temperatures may trigger these.
- Assume that flood water contains sewage and might be harmful for human and livestock consumption.
- Before leading livestock across a river, check whether the water level is rising. This is especially necessary if it is already raining, but remembers that there could be a storm further upstream and floodwaters could be on the way.
A comprehensive list of strategies can be found in the monthly NAC Advisory. It can be accessed from the www.daff.gov.za, www.agis.agric.za and www.elsenburg.com websites.
