Environmental Flow Requirements of the Fish River and the Orange-Senqu River Mouth

Background

The Orange-Senqu River riparian States (Botswana, Lesotho, Namibia and South Africa) are committed to jointly addressing threats to the shared water resources of the Basin. This is reflected in bilateral and basin-wide agreements between the riparian states and led to the formation of the Orange-Senqu River Commission (ORASECOM) in 2000.

The ‘Orange-Senqu Strategic Action Programme’ Project supports ORASECOM in developing a basin-wide plan for the management and development of water resources, based on Integrated Water Resources Management (IWRM) principles.

The water resources of the Orange-Senqu River are heavily utilised and the system is highly regulated with 23 major dams within its Basin. It is also connected to other river systems for water import and export via six inter-basin water transfer schemes.

The project presented here addresses Environmental Flow Requirements (EFR) of the ephemeral but nevertheless significant Fish River, and the Orange-Senqu River, from its confluence with the Fish River downstream to the Orange-Senqu River mouth.

This section of the basin has not been covered in any detail by the earlier studies carried out during 2009-2010. The need for establishing the Environmental Flow Requirements is becoming increasingly` urgent due to the fact that two large dams, one in the Lower Orange (Vioolsdrift Dam) and one in the Lower Fish (Neckartal Dam), are at an advanced state of planning.

Project's on-line map

Project's on-line map presents all spatial data generated during the project. The map is hosted on the WIS geoserver system. The map provides interactive access to spatial data and attribute data associated with spatial features.

View map

Documents

EFR Database Manual


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TR10_Crerar, S, et al 2011b Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Scoping paper and terms of reference


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TR19_Louw , D, et al 2011 Research Project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Inception report


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TR22_Louw, D, et al 2012 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Delineation of management resource units


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TR26_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Consequences of flow scenarios on ecosystem services


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TR27_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River EFR Assessment, Volume 1, Determination of Fish River EFR


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TR28_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River Mouth: River EFR Assessment, Volume 2, Fish River EFR supporting information


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TR29_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River EFR Assessment, Volume 1, Determination of the lower Orange River EFR


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TR30_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River EFR Assessment, Volume 2, Lower Orange River EFR supporting information


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TR31_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: River and Estuary EFR Assessment, Hydrology and river hydraulics


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TR32_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Estuary and Marine EFR Assessment, Volume 1, Determination of Orange estuary EFR


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TR33_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Estuary and Marine EFR Assessment, Volume 2, Orange estuary EFR supporting information


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TR34_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Estuary and Marine EFR Assessment, Volume 3, assessment of the role of freshwater inflows in the coastal marine ecosy


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TR35_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: EFR monitoring programme


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TR36_Louw, D, et al 2013 Research project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Database


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TR37_Louw, D, et al 2013 Research Project on environmental flow requirements of the Fish River and the Orange–Senqu River mouth: Summary report


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TR45_Brown, C, 2013 Basin-wide Environmental Flow Regime in the Orange-Senqu River Basin


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A prototype methodology for Environmental Water


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Avenant, MF, 2010 Challenges in using fish communities for assessing ecological integrity of non-perennial rivers


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Rossouw, L, et al 2005 Environmental water requirements in non-perennial systems


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CSIR, 2011 Orange River Estuary Management Plan: Situation assessment Report submitted to Eco-Pulse


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Macfarlane, DM 2013 Strategic Management Plan for the Orange River Mouth Ramsar site


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Presentation_Towards_a_Management_Plan_for_Orange_River_Estuary_24_March_2011


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Data

Below are all data sets generated within the project. GIS data asociated with these datasets can be accessed either through the on-line map or through the "map" link under each dataset

Ecostatus Assessment Indices


Ecological Importance and Sensitivity

Results of assessment of Ecological Importance and Sensitivity according to methodology by Dr CJ Kleynhans (DWAF, 1999, updated in 2010). Results based on 2012 surveys.
data files   map

EcoStatus Level 4

Results of the EcoStatus model that integrates assessments for individual biophysical components of the system, as per Kleynhans & Louw (2007). Results based on 2012 surveys.
data files   map

Fish Response Assessment Index

Fish Response Assessment Index (FRAI) according to Kleynhans (2007). Index determined based on 2012 surveys.
data files   map

Geomorphological Driver Assessment Index

Geomorphological Driver Assessment Index (GAI) according to Rountree and du Preez (in prep). Index determined based on 2012 surveys.
data files   map

Index of Habitat Integrity

Index of Habitat Integrity (IHI) assessed for the instream and riparian components, according to Kleynhans et al. (2009a). Index determined based on 2012 surveys.
graphs   data files   map

Macroinvertebrate Ecological Traits

Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map

Macroinvertebrate Response Assessment Index

Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map

Physico-chemical Driver Assessment Index

Physico-chemical Drivers Assessment Index (PAI) according to Kleynhans et al.(2005) and DWAF (2008b). Index values based on 2012 surveys.
data files   map

Riparian Vegetation Response Assessment Index

Riparian Vegetation Assessment Index (VEGRAI) according to Kleynhans et al. (2007). Index determined based on 2012 surveys.
data files   map

Scenario Ecostatus Assessment


EcoStatus Level 4

Results of the EcoStatus model that integrates assessments for individual biophysical components of the system, as per Kleynhans & Louw (2007). Results based on 2012 surveys.
data files   map

Fish Response Assessment Index

Fish Response Assessment Index (FRAI) according to Kleynhans (2007). Index determined based on 2012 surveys.
data files   map

Geomorphological Driver Assessment Index

Geomorphological Driver Assessment Index (GAI) according to Rountree and du Preez (in prep). Index determined based on 2012 surveys.
data files   map

Macroinvertebrate Ecological Traits

Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map

Macroinvertebrate Response Assessment Index

Results of assessment of river health with a method developed for this study, which was based on a number of key ecological traits that were rated and weighted in terms of their importance in defining the Present Ecological State of benthic macro-invertebrates.
data files   map

Physico-chemical Driver Assessment Index

Physico-chemical Drivers Assessment Index (PAI) according to Kleynhans et al.(2005) and DWAF (2008b). Index values based on 2012 surveys.
data files   map

Riparian Vegetation Response Assessment Index

Riparian Vegetation Assessment Index (VEGRAI) according to Kleynhans et al. (2007). Index determined based on 2012 surveys.
data files   map

Riverine Fauna

Results of assessment of riverine fauna conditions under the flow scenarios based on a process developed especially for this project. The main components of this process that are considered comprise the expected riverine fauna species to the area, their probability of occurrence and quality of habitat present. Assessment done on the basis of survey performed in June 2012.
data files   map

Raw Ecological Data


Diatoms

Diatom abundances at projects sites surveyed in 2012, and at other sites in the basin surveyed between 2008 and 2012.
data files   map

Estuary Birds

Bird species abundances surveyed in November 2012 at 4 locations within the Orange River Estuary
data files   map

Estuary Fish

Fish catches in the Orange River Estuary.
data files   map

Estuary Macroinvertebrates

Macroinvertebrate counts at a number of sites in the Orange River Estuary in Sept 2014, but also in 2004 and 2005
data files   map

Estuary Macrophytes

Macrophytes present in the Orange River Estuary.
data files   map

Estuary Microalgae

Microalgae counts at a number of locations within the Orange River Estuary
data files   map

Fish

Fish counts at projects sites surveyed in 2012.
data files   map

Macroinvertebrates

Macroinvertebrate counts at projects sites surveyed in 2012, and between 2008 and 2012.
data files   map

Hydrological Data


HEC-RAS hydrodynamic model

Model configuration and results of modelling of Fish River hydrodynamics in the Neckertal-Ais-Ais reach. Data stored in the native HEC-RAS format.
data files   map

monthly rainfall input to model

These are monthly rainfall amounts for each of the subcatchments simulated in the Pitman model. The data were derived from observations at individual stations, which were interpolated and converted to subcatchment-area monthly totals. Data cover the period of Oct 1930-Sep 1995.
graphs   data files   map

Pitman model parameters

These are parameters of Pitman model obtained during model calibration.
data files   map

present day disaggregated daily flows

These are river discharges at a number of 'nodes', or outlets of subcatchments, simulated with a calibrated Pitman hydrological model for current conditions in the basin. The simulations cover the period of Oct 1930-Sep 1995. Sata presented here are disaggregated using statistical methods from monthly output of the Pitman model.
graphs   data files   map

present day monthly flows

These are river discharges at a number of 'nodes', or outlets of subcatchments, simulated with a calibrated Pitman hydrological model for current conditions. Current conditions - cover the period of Oct 1930-Sep 1995. Pitman model is run at monthly time step, and data presented here are monthly. Files contain either 'incremental' flow, i.e. flow generated within subcatchment corresponding to a node, or total flow, i.e. flow generated upstream from a node, or, in case of dams, spill flow.
graphs   data files   map

scenario disaggregated daily flows

These are river discharges at a number of 'nodes', or outlets of subcatchments, simulated with a calibrated Pitman hydrological model for prescribed water management and development scenarios. The simulations cover the span of 66 years. Data presented here are disaggregated using statistical methods from monthly output of the Pitman model.
graphs   data files   map

scenario monthly flows

These are river discharges at a number of 'nodes', or outlets of subcatchments, simulated with a calibrated Pitman hydrological model for prescribed water management and development scenarios. The simulations cover the span of 66 years. Data presented here are monthly.
graphs   data files   map

stage-discharge relationship

These are results of measurements topographic transect, water level and flow discharge at cross-sections at core sites.
data files   map

WReMP Fish River Water Management Model

Model configuration and results of modelling of Fish River with water management model WReMP. Data stored in the native WReMP format.
data files   map

WRYM Integrated Vaal River System Model

Model configuration and results of modelling of Orange River basin with water management model WRPM. Data stored in the native WRPM format.
data files   map

Water Quality and Sediment Data


Estuary Sediment

Results of granulometric analyses of sediment samples from a number of locations within the Orange River Estuary. Locations of sampling sites not georeferenced.
data files   map

Estuary Water Quality

Results of water quality measurements from a number of locations within the Orange River Estuary.
data files   map

Metadata


Shapefiles metadata

Shape files presented in this website contain attribute tables that store refrences to data files pertaining to each of the georaphical feagures. The shapefile metatdata contains description of column names of these attribute tables. It is a Comma Separated Value file that can be read with a text editor or opened in MS Excel.
data files   

Maps

These are project maps included in the project reports. All are in jpg format. GIS data underlying them are shown elsewhere in this page

basemap

Basemap of the project. Shows location of the study site, subdivision of the rivers into Management Resource Units, gauges etc.
Low resolution   High resolution

diatom

Map shows location of diatom sampling sites
Low resolution   High resolution

nodes

Location of outlets of subcatchments represented in the Pitman hydrological model run for the project
Low resolution   High resolution

raingauges

Location of rain gauges used in the study
Low resolution   High resolution

waterquality

Map shows location of water quality monitoring and sammpling sites
Low resolution   High resolution