ProEcoServ. Water, energy and food security in the grasslands. Jeanne Nel

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1 ProEcoServ Water, energy and food security in the grasslands Jeanne Nel

2 Acknowledgements WATER QUALITY Paul Oberholster, James Dabrowski, Klaudia Schachtschneider WATER & HUMAN HEALTH Bettina Genthe ECOSYSTEM SERVICES Belinda Reyers, Christine Colvin, David Le Maitre

3 Outline Water, energy and food security in SA Built and ecological infrastructure Journey into a heavily used grassland catchment Problems, linkages, science, suggestions 3 take-home messages

4 Water, energy and food security are linked Inextricably linked Actions in one impacts on the others Often through water A nexus approach integrates management and governance across all sectors and scales Water quality and quantity is key Up until recently, water has been the least considered in the nexus debate

5 Put water at the centre of the nexus debate 1: Our catchments are already stressed Water Availability(Mm3/yr) Demand outstrips supply 98% of usable surface water already allocated 32% projected increase in water demand by 2030

6 Put water at the centre of the nexus debate 1: Our catchments are already stressed Water Availability(Mm3/yr) U = Urban / industrial effluent pathogens + organics T = Acidic atmospheric deposits G = Groundwater contamination - fluoride and/or nitrate A = Agricultural chemicals E = Excessive sediment M = Metals (mining) R = Radioactivity E S S = Salinity G E U G R A A M A U M R U A E U E G A E U A M A S U U A M M A U T M A A U A U E A A E E U S A U A S S U S U Dr Pete Ashton Demand outstrips supply 98% of usable surface water already allocated 32% projected increase in water demand by 2030 Water quality problems growing 65% dams eutrophic or borderline eutrophic

7 Put water at the centre of the nexus debate 2: Spatial overlap creates competing interests Water supply 50% water from 12% of our land Coal Deposits Overlap with best agricultural land & all sources of major inland rivers Agriculture & Forestry 13% of land arable; only 3% high potential

8 Put water at the centre of the nexus debate 3: Water infrastructure can t keep up with demand Households with no access to piped water has decreased 15% in % in 2011 But barely keeping pace with population growth Rural areas still an infrastructural challenge 2011 census

9 Rural communities often rely on natural water sources for drinking water They are highly vulnerable to health hazards associated with agricultural and mining effluent

10 Ecological infrastructure Built infrastructure cannot keep pace Healthy ecosystems provide infrastructure that we seldom recognise River or filter strips absorb pollutants and also provide habitat for our biodiversity Healthy rivers have a powerful way of fixing themselves by absorbing pollutants

11 Blended ecological and built infrastructure Not either-or Ecological infrastructure can help built infrastructure play a better role in providing a secure water future Ecological infrastructure usually has a lower maintenance and cost

12 A journey through the Olifants catchment Transboundary zone KRUGER NATIONAL PARK Four zones

13 Extreme example of multiple pressures Mining SA 5 th largest coal producer in the world 90% from the Witbank coal fields Sewage 55% in drastic need of improvement Crop Production 2 nd largest irrigation scheme in SA R1 billion export market Grows 65% of vegetables of a major food company Livestock Production Intensive feedlots 4 x more animals than humans Lots of animal waste

14 Mining outflows: Acid Mine Drainage Acidifying of groundwater and rivers Open cast mines increase soil permeability Rainwater mixes with the mineral & becomes acidified Enters groundwater easily 100 year legacy of abandoned mines To date focus has been on abandoned gold mines Open cast coal mines have widespread impacts Not only about ph Acid water carries toxic heavy metals which need removing Klipspruit Brugspruit Discharges into rivers MINE STATUS Abandoned Current

15 Impacts of mining outflows Exposure for informal settlements Pollutants in air DNA studies show increased genetic damage Dose-response studies for arsenic show increased cancer risk 3 x higher at our study sites 100 x higher in areas with raw or ph neutralised AMD Higher reporting of a range of medical symptoms in mining areas Treatment of water for drinking and power generation is VERY expensive Mining outflows in water Bioaccumulation in fish Bioaccumulation in crops

16 Agricultural & urban outflows: Eutrophication Algal blooms caused by high nutrient loads Sources of high nutrients Point source: Sewage Non-point source: Fertilizers 65% dams eutrophic or borderline eutrophic 90% of blooms associated with toxic cyanobacteria Regime shifts to eutrophic state Loskop Dam in this state since 2008

17 Impacts of eutrophication Cyanobacteria toxins accumulate in crops Colorectal and liver cancer Chokes irrigation canals Decreases lifespan of irrigation equipment Causes crop infertility Decreased property value Fish kills Treatment very expensive Normal sand filters don t extract toxins 78 types of liver and neurotoxins

18 How can science help? Impacts made explicit Water, food, energy conservation, transboundary agreements Enables informed trade-offs But how can science help with solutions?

19 Maintain existing ecological infrastructure Mohlapitse Healthy tributaries dilute pollutants of downstream hard-working rivers Freshwater Ecosystem Priority Areas (FEPAs) River FEPA & sub-catchment Wetland FEPA Nel et al Atlas of FEPAs. Water Research Commission Report TT 500/11

20 Understand drivers of phosphate loading at a catchment scale + Soil + Land Use Slope + Sub-catchment + Weather data SWAT Model Dabrowski et al Water Research Commission Report K5/1984

21 Develop phosphate reduction strategies 97% phosphate in Middelburg Dam is nonpoint; Witbank and Loskop dams are point source Steenkoolspruit exports far higher phosphate loads than Wilge Wilge Loskop dam Middleburg dam Witbank dam PRELIM Phosphate reduction scenarios: Steenkoolspruit A 1 mg/l national standard at sewage works can reduce loads by ~40% in Witbank and Loskop Dams Average phosphate export (kg/ha/yr) The 0.1 mg/l international standard does not give substantially lower reductions masked by non-point Dabrowski et al Water Research Commission Report K5/1984

22 Reduce phosphate loads of sensitive river stretches first Phosphorus sensitivity index shows: Cobble and bedrock streams are particularly sensitive Sand or mud bottomed rivers less sensitive Restore most sensitive areas first Sewage works that discharge into cobble or bedrock streams Cattle drinking points and feedlot location Oberholster et al modified phosphorus sensitivity index.. Journal of Applied Limnology

23 Switch from fertilizer to microbes Some prominent farmers in the Olifants have already made the switch Can utilize natural organic phosphorus in the soil; no need for added fertilizer Compost tea stimulates microbial action which stimulates root and plant growth Bill Collect

24 Restore wetland functions Wetlands filter out sediment and pollutants green kidneys Some wetland plants take up metals Zaalklapspruit restoration with CoalTech Research Association Can we make a difference to the quality of the water flowing through the wetland? ph and metals Dr Klaudia Schachtschneider

25 Make better use of artificial wetlands Wetlands = less expensive Only require periodic maintenance Reuse/recycle water Provide habitat for plants and animals Green jobs Paul Oberholster Mokolo catchment, Waterberg

26 Performance of artificial wetlands Need big area, low flow for best performance Country Area (m2) Flow (m3/day) Average Performance* (%) UK USA Czech Republic Italy Jamaica * For removal of total phosphates and faecal coliforms

27 Evaporation ponds for sewage works Tubatse, Limpopo Middle Olifants Effective & low maintenance How well do the plants contribute to good performance? Fortuitous; should we replicate this elsewhere?

28 3 take-home messages

29 1: Incorporate ecological infrastructure in development planning Presidential Infrastructural Development Plan R4 trillion R573 billion for water infrastructure R30 billion to rehab abandoned mines

30 2: Be smarter with the water we have Economic growth more water Putting water at centre of decisions will make trade-offs explicit e.g. mining in areas of high natural run-off

31 3: Mobilise shared action & partnerships At national, catchment and local scale Business will be affected by this debate and need to be involved No silver bullet implement diverse options Economic, technological, regulatory, educational AND ecological Place water at the centre of all sectors National Water Resources Strategy recognizes this as one of their Core Strategies Requires involvement of the nontraditional water sector

32 Thank you!