Berg River study points to importance of monitoring in managing catchments

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The Water Wheel July/August 2018 33
Berg River study points to importance of monitoring in
managing catchments
DROUGHT AND AGRICULTURE
Low water levels in the Berg River Catchment have resulted in
increased pollution in places, triggering the need for farmers
to consider adapting their farming practices to ensure future
protability. The Berg River that rises in the Groot Drakenstein
Mountains, near Franschhoek, and discharges in the Atlantic
Ocean at Velddrift, supports land uses such as agriculture,
forestry, urban development and conservation. It is an important
producer of table and wine grapes in South Africa, with more
than a fth of the country’s wine cellars located here.
Agricultural experts already expressed concerns in 2008 that
deteriorating water quality might aect the ability of the region
to export grapes and other fruit. This would have a signicant
impact not only on the regional economy of the Western Cape,
but also the national economy. The area is a major contributor
to foreign currency earnings, and is important for the welfare of
thousands of people who are dependent for their livelihoods on
the agricultural sector in the region.
The current drought conditions in the Western Cape, combined
with the possibility that these might be the signs of climate
change, the poor state of some treatment plants and the
continued rapid rate of urban developments in the Berg River
Catchment have further highlighted these risks.
How these conditions might impact on the future water quality
risks in the Berg River and the associated options for farmers
to adapt to changing water quality risks were the subject of a
Feature
A recently completed research project has investigated ways to adapt farming in the Berg
River Catchment to drought conditions and urbanisation with increased monitoring and
economic modelling. Article by Annabel Horn, Leanne Seeliger, Marlé Kunneke, Willem
Homan, James Cullis, Nico Rossouw, Lloyd Fisher-Jees and Wilna Kloppers.
All images supplied by Western Cape Government

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34
Drought and agriculture
recent study initiated by the Western Cape Government as part
of the Berg River Improvement Project (BRIP).
The study modelled three typical economic whole farm
scenarios in dierent regions in the Berg River Catchment to
evaluate the likely impacts and associated cost of dierent
on-farm adaptation scenarios. These could then be contrasted
against alternative solutions aimed at addressing the root causes
of the problems in the catchment, which might be harder to
achieve.
In the baseline scenario, farms were modelled to have good
quality river water for irrigation and continue to place about
70% of the produce into higher priced export markets. In
scenario two, farmers found it dicult to reach the irrigation
water quality standards for fruit export and placed the fruit into
the domestic market with lower prices and moved from table
grape production to wine production. In scenario three, farmers
were compelled to put a water treatment system into place for
the cleansing of river water prior to irrigation. This signicantly
aected the capital outlay of farmers.
“The area is a major contributor
to foreign currency earnings, and is
important for the welfare of thousands
of people who are dependent for their
livelihoods on the agricultural sector in
the region.”
For scenario 2, the modelling showed that while selected
red wine cultivars might fetch a better market price here due
to lower yields, overall there would be a signicant loss in
productivity. Moreover, it was predicted that if farmers switched
to wine farming to remain protable there would be an added
infrastructure cost of cellars that would need to be built.
The analyses showed that protability fell in scenario two, where
the modelled farm had to adjust to the lower domestic prices as
compared with export prices. In scenario three, where farmers
had found a solution to manage the water quality themselves
Inflow into the Berg River Dam was affected severely by the recent drought.
The Berg River Catchment.

The Water Wheel July/August 2018 35
with a private water treatment facility, protability was better
than scenario two.
A number of recommendations were suggested to address the
situation. These included:
• The continuous monitoring and analysis of water quality in
the Berg River, both over time and along the length of the
river.
• The inclusion of stormwater management, stormwater
quality and timely wastewater treatment work upgrades
into municipal services development plans.
• The monitoring and analysis of population and building
trends that impact on water quality.
• The recording of water user association data with regular
updates and collated information for each section of the
river being made accessible to relevant authorities. During
times of drought this will enable individual farms to put the
required curtailments in place to avert a crisis in both water
allocation and water quality in the river caused by reduced
dilution.
• The conveying of real-time water quality data to farmers.
This could be in the form of bulk short message services
via cell phones. This information would be useful for an
emergency, like a spill, as monitoring and laboratory
analysis takes time and so cannot be completed in real
time.
• The possible establishment of water treatment systems for
river irrigation water of sensitive crops on farms.
Researchers believe this study has relevance for decision-making
in the whole of South Africa and other areas in the world
that face challenges like declining water quality, increasing
urbanisation and climate change. It pointed to the importance
of monitoring water quality and quantity to successfully manage
water catchment areas.
Drought and agriculture
Wetlands below the Berg River Dam.
Marle Kunneke, DEA&DP, Western Cape Government , monitoring
in the Berg River
Acknowledgement: Department of Environmental Aairs and
Development Planning (DEA & DP), Western Cape Government,
provided funding for this research.