SCENARIOS TO MANAGEMENT CLASSES ECOSYSTEM SERVICES DEMONSTRATION

Socio Economics Looking at the value of water and measure impact of scenarios. Although they are integrated there are two fundamental pieces of work applied. Look at value of water abstracted and express the return on utilisation. This can be expressed in Rands and in terms of jobs Look at value of water that remains in the system and what this means for utilization of associated goods and services. This is expressed as an order of magnitude impact of scenarios against a status quo reference point.

What is Ecosystem Services? Ecosystem Services are the goods and services provided by the river (and associated ecological systems) that result in a value being produced for consumers. Provisioning services are the most familiar category of benefit, often referred to as ecosystem ‘goods’, such as foods, fuels, fibres, medicine, etc., that are in many cases directly consumed. Other services include cultural services (ritual use of rivers, aesthetic or historical importance) regulating services (e.g. water quality inputs), and supporting services (e.g. nutrient formation)

Ecosystem services approach The following methods were used to generate a picture of the most important Ecosystem Services that are associated with the riverine system and may be subject to change under a potential range of operational scenarios. –Literature survey –Census information –Analysis of maps and Google Earth images –Interviews in the catchment where priorities are identified.

The importance of the Ecosystem Services per SQ is described Links are made to determine the Ecosystem Services that are important and the types of communities that make use of, or are dependent, on types of Ecosystem Services. Each SQ attracts a score based on a weighted rating of each of the aspects that make up the Ecosystem Services. Scale is 0-5 “Hotspots” and key features that may influence management decisions are identified. Ecosystem services approach

SQ Cultural Services (0-5) Weight Provisioning Services (0-5) Weight Regulating Services Use (0-5) Weight Supporting services Weight Score T40A T40A Ecosystem services approach

Process Evaluate changes to Ecosystem Services against scenarios in expert workshop format. The specialists (biophysical) identify the potential change that each of the key Services may undergo. The potential change is used as a factor in later calculations.Eg, no change = 1, a 50% increase = 1.5, and a 20% decrease = 0.8. Eg: Each river reach and each scenario are analysed to determine how Services may react.

Rural Urban Irrigation Rural Small Dams SFRs Industrial Nature Reserve Estuary TYPICAL WATER RESOURCE SYSTEM – STATUS QUO Trout farming, recreation. Commercial agric. Limited livelihood ecosystems services use but high intrinsic values. Rural: Subsistence, settlements high ecosystems services use, livelihoods NB Gorge, protected area. Little access low ecosystem use Coastal belt, some ecosystems use associated with estuary

DRIVERS SCENARIOS Dam raisingIncreased irrigation Increased waste water EWR release A Release down river  B  Re-use C ; enlarge pipe & canal Sea outfall -10% droughts D ; Release down river with some EWR seasonality -30%, Existing canal -10% droughts

Rural Urban Irrigation Rural Small Dams SFRs Industrial Nature Reserve Estuary SCENARIO CONSEQUENCES Commercial Farming – Impact small SC A, B, C, D remain = to status quo No impact from scenario Some impact but little access low ecosystem use so significance limited. SC A –ve, B+ve, C, D small +ve/neutral Coastal belt, Recreation in estuary disturbed. SC A – ve, B+ve, C, D small +ve/neutral No impact from scenario

Scenario consequences Define in terms of – Services, e.g. provisioning services – Subsets of services, e.g. fish used for subsistence purposes – Species, were applicable. Assess magnitude of impact per scenario and rate based on factor of 1. NB – we would only be interested in those applicable to the site

Example of Scenario consequences SC ASC B SC C+D SedgesSedgeCyprus Sp PhragmitiesReeds Phragmities mauritianus Spanish ReedArunda donax0.911

Integrated Scenario Impact Combine the various subsets and rate each of the “services categories” i.e each of provisioning services, cultural services, regulating services, supporting services would have a summarised rate relative to “1”. Weight with significance of impact – driver is intensity of utilisation/importance of service - and score overall. Each EWR will have a score per scenario.

Scenario B = 1.10 Scenario D = 1.02 Current state = 1, Scenario C = 1 Scenario A = 0.92 Ecosystem services consequences