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Fish Water Flats Waste Water Treatment Works: Biogas Facility

WETLAND IMPACT REPORT

Prepared for:

Royal Haskoning DHV (Pty) Ltd

Prepared by:

EOH Coastal & Environmental Services

GRAHAMSTOWN 67 African Street

Grahamstown, 6140 046 622 2364

Also in East London, Port Elizabeth, Johannesburg, Cape Town & Maputo

April 2016

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law and practices of South Africa.

Fish Water Flats WWTW Biogas Facility – Wetland Impact Assessment

EOH Coastal & Environmental Services i RHDHV (Pty) Ltd.

THE PROJECT TEAM

Ms Caroline Evans, Wetland and Ecological Specialist, is an Environmental Consultant at Coastal and Environmental Services (CES) and holds a BSc degree in Environmental Science and Zoology (distinction) and a BSc Honours degree in Environmental Science (distinction) both from Rhodes University (RU). Caroline‟s undergraduate degree included both commerce and natural sciences. Caroline's honours dissertation evaluated the economic impacts of degradation of the xeric subtropical thicket through farming practices, focusing on the rehabilitation potential of the affected areas in terms of carbon tax. She has a broad academic background including statistics, economics, management, climate change, wetland ecology, GIS, rehabilitation ecology, ecological modelling and zoology. Dr Cherie-Lynn Mack, holds PhD and MSc (with distinction) degrees in Environmental Biotechnology, with a BSc degree in Microbiology and Biochemistry. She has postgraduate research experience in industrial and domestic wastewater treatment technologies, with particular emphasis on the coal and platinum mining industries. Her interests lie in the water sector, with experience in ecological reserve determination and water quality monitoring and analysis. She has experience in water quality analysis and industrial wastewater treatment research. She is currently employed in the East London office of CES as a senior environmental consultant. Dr Alan Carter, Director of the East London Office, has extensive training and experience in both financial accounting and environmental science disciplines with international accounting firms in South Africa and the USA. He is a member of the American Institute of Certified Public Accountants and holds a PhD in Plant Sciences. He is also a certified ISO14001 EMS auditor with the American National Standards Institute and the British Standards Institute.


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LIST OF ACRONYMS CES Coastal and Environmental Services

DWA Department of Water Affairs

DWAF Department of Water Affairs and Forestry

DWS Department of Water & Sanitation

ECO Environmental Control Officer

EIA Environmental Impact Assessment

FEPA Freshwater Ecosystem Priority Areas

HGM Hydro-Geomorphic Method

IUCN International Union for Conservation of

Nature

NEFEPA National Freshwater Ecosystem Priority

Areas

NEMBA National Environmental Management

Biodiversity Act

NWCS The National Wetland Classification System

PES Present Ecological State

RU Rhodes University

SANBI South African National Biodiversity Institute

WEF Wind Energy Facility

WRC Water Research Commission


EOH Coastal & Environmental Services iii RHDHV (Pty) Ltd.

TABLE OF CONTENTS

1 INTRODUCTION ..................................................................................................................... 1 1.1 Project Description and Locality ....................................................................................... 1 1.2 Approach ......................................................................................................................... 2

2 TOOLS AVAILABLE FOR WETLAND ASSESSMENT .......................................................... 3 2.1 Wetland definition ............................................................................................................ 3 2.2 Wetland Importance ........................................................................................................ 3 2.3 Tools available to define wetlands and watercourses ...................................................... 4

2.3.1 National Freshwater Ecosystem Priority Areas ............................................................ 4 2.3.2 WET-Health and Present Ecological State ................................................................... 5

3 DESKTOP DESCRIPTION OF AQUATIC ENVIRONMENT .................................................... 9 3.1 Wetlands ......................................................................................................................... 9

4 PHYSICAL DESCRIPTION OF AQUATIC ENVIRONMENT ................................................. 11 4.1 Collection of site data .................................................................................................... 11 4.2 Wetlands identified surrounding the Fish Water Flats WWTW site. ............................... 11

The following wetlands were identified within 500m of the proposed biogas facility on the Fish Water Flats WWTW site. ....................................................................................................... 11 4.2.1 Wetland 1 .................................................................................................................. 12 4.2.2 Wetland 2 .................................................................................................................. 12 4.2.3 Photographs of Wetland 1 & 2 ................................................................................... 13

4.3 Present Ecological State (PES) ..................................................................................... 14 4.3.1 Hydrology .................................................................................................................. 14 4.3.2 Geomorphology ......................................................................................................... 15 4.3.3 Vegetation ................................................................................................................. 15

5 IDENTIFIED IMPACTS OF THE FISH WATER FLATS WWTW BIOGAS FACILITY ........... 17 5.1 Identification of potential impacts ................................................................................... 17

5.1.1 Sedimentation ............................................................................................................ 17 5.1.2 Alteration of the environment beyond the development footprint ................................ 18 5.1.3 Pollution of Wetland Systems .................................................................................... 19

6 CONCLUSIONS AND RECOMMENDATIONS ..................................................................... 20 7 REFERENCES...................................................................................................................... 21

LIST OF FIGURES

Figure 1.1. Location of the Fish Water Flats WWTW: Port Elizabeth, Nelson Mandela Bay Metropolitan Municipality. ............................................................................................................................................... 1

Figure 2.1: The HGM types for South African Inland wetlands (SANBI, 2009). ................................................ 6 Figure 2.2: The steps involved in the WET-Health Level 1 rapid assessment (MacFarlane et al. 2007). ........ 7 Figure 3.1. NPEFA Classification of the water systems surrounding the existing Fish Water Flats WWTW

where the biogas facility will be constructed .............................................................................................. 9 Figure 3.2. 100 Year Floodline of Estuary indicating that the estuary does not reach the existing

infrastructure or the proposed biogas facility location within the Fish Water Flats WWTW .................... 10 Figure 4.1. Wetlands identified within the proximity of the construction activities for the proposed Biogas

Facility within the footprint of the Fish Water Flats WWTW .................................................................... 11 Figure 5.1. Wetlands identified within the proximity of the construction activities for the proposed Biogas

Facility within the footprint of the Fish Water Flats WWTW .................................................................... 17

LIST OF TABLES

Table 2.1: Description of A – F ecological categories based on Kleynhans (1996, 1999). ............................... 8


EOH Coastal & Environmental Services 1 RHDHV (Pty) Ltd.

1 INTRODUCTION

1.1 Project Description and Locality The Fishwater Flats Wastewater treatment works (FWF WWTW) is a conventional activated sludge treatment works originally commissioned in 1976 to treat 80 Ml/day of domestic sewage and 32 Ml/day of industrial wastewater. In 1997, construction increased treatment capacity of the industrial stream to 52 Ml/d. The original activated sludge reactors were upgraded to include biological nitrate removal in 2001. It is planned to increase the capacity of FWF WWTW to 170 Ml/d. The Nelson Mandela Bay Metropolitan Municipality (NMBMM) has proposed the upgrading and modernisation of the 30-year old Fishwater Flats Wastewater Treatment Works (WWTW). The proposed development is subject to the NMBM Sewer Master Plan (SSI Engineers and Environmental Consultants, September 2009) and will be located entirely within the boundaries of the existing works. As part of a separate development geared towards a renewable energy scheme, it is the intension of the NMBMM to design and construct a Biogas (Cogeneration) Plant for the stabilisation and beneficiation of sludge that is generated from the FWF WWTW. The sludge beneficiation process will produce heat and electricity through the production of methane from the anaerobic digestion of sludge. The WWTW is situated within the outskirts of the Swartkop‟s River Estuary and a number of wetlands associated with the estuary may be impacted by the upgrading of the facility. This report outlines the impacts and associated mitigation measures based on the technical information available.

Figure 1.1. Location of the Fish Water Flats WWTW: Port Elizabeth, Nelson Mandela Bay Metropolitan Municipality.



1.2 Approach The study site and surrounding areas were described using a two-phased approach. Firstly, a desktop assessment of the project area was conducted in terms of GIS data available. This included the consideration of:

» 1:50 000 vector maps of wetlands

» The National Wetland Classification System (NWCS) Further to the above, a site visit was conducted on the 11th April 2016 in order to:

» Delineate any wetlands found onsite;

» Assess the wetland health; and

» Assess the current land-use. The findings of the site visit served to inform the impact identification process of the proposed development and assist in determining how significant these impacts would be for the surrounding watercourses and wetlands.



2 TOOLS AVAILABLE FOR WETLAND ASSESSMENT

2.1 Wetland definition “Wetland” is a name given to a variety of ecosystems ranging from rivers, springs, seeps and mires in upper catchments, to midland marshes, pans and floodplains, coastal lakes, mangrove swamps and estuaries at the bottom of a catchment. These ecosystems all share the common primary driver of water and its prolonged presence is a fundamental determinant of soil characteristics, vegetation and animal life (DWAF, 2005). The National Water Act (Act No. 36, 1998) defines wetlands as: “Land which is transitional between terrestrial and aquatic systems where the water table is usually at or near the surface, or the land is periodically covered with shallow water, and which land in normal circumstances supports or would support vegetation typically adapted to life in saturated soil.” Thus wetlands must have one or more of the following characteristics:

» Hydromorphic soils: characteristic soils of prolonged saturation;

» Hydrophytes, at least occasionally: highly saturated plants; and

» High water table: A high water table that results in saturation at or near the surface, leading to anaerobic conditions developing in the top 50cm of the soil.

Wetlands are formed from a combination of geology, hydrology and topography. These landforms form in parts of a catchment where the movement of water is slowed down or obstructed, causing soil to become temporarily, seasonally or permanently waterlogged.

2.2 Wetland Importance South Africa is a Contracting Party to the Ramsar Convention on Wetlands and has thus committed itself to the intergovernmental treaty, which provides the framework for the national protection of wetlands and the resources they could provide. The Ramsar Convention is the only global environmental treaty that deals with a particular ecosystem. The treaty was adopted in the Iranian city of Ramsar in 1971 and the Convention's member countries cover all geographic regions of the planet. Wetland conservation in South Africa is now driven by SANBI under the requirements of the National Environmental Management Biodiversity Act (NEMBA, 10, 2004). In natural capital terms, wetlands may be seen as a significant economic investment. This monetary value is rooted to the fact that the primary tasks of a wetland are to process water and regulate runoff. This is important as the South African economy is heavily dependent on water and yet the climatic variability of the country has meant that for the most part rainfall occurs as intermittent, high intensity storms. The inherent value of wetlands is that they protect and regulate this water source by acting like sponges, soaking up water during flood events and releasing it during dry periods (DWAF, 2005). By regulating water flows during floods, wetlands may reduce flood damage and help prevent soil erosion. As natural filters wetlands help to purify water by trapping pollutants, heavy metals and disease causing organisms. The most common ecosystem services provided by wetlands are:

» Improved water quality

» Flood attenuation

» Sediment trapping

» Reduce number of water borne diseases

» Herbal medicine

» Water storage



These ecosystem services are provided at very little cost but with significant payback for the South African economy. Despite being classified as the third most significant life support system on earth (IUCN, 1980), wetlands are some of the most threatened habitats in the world today. Breen & Begg (1989) reported that more than 50% of the wetland inventory in South Africa had disappeared. The main issues have been draining wetlands for crops and pastures, poorly managed burning and grazing resulting in headcut and donga erosion, planting alien invasive vegetation, mining, pollution and urban development. These have been significant as they alter the natural flow of water in wetlands and as water is the driver of wetland formation it follows that any changes would be damaging. A buffer around a wetland is usually recommended in order to protect the wetland from development in the vicinity. Aside from the negative impacts of construction in the vicinity of a watercourse or wetland, a major impact that needs to be considered should be the geotechnical competence of soil which is often waterlogged and prone to flooding. Wetland soils are usually high in clay and prone to wet and dry periods, allowing for expansion and contraction of soils. The wetland and watercourse buffers are therefore also important with regards to the demarcation of areas that are not good to build on/in due to the high soil moisture content and unstable soils. Developing solutions to these problems would be expensive and may not be sustainable in the long term.

2.3 Tools available to define wetlands and watercourses 2.3.1 National Freshwater Ecosystem Priority Areas After several years of development and testing, a National Wetland Classification System (NWCS) was completed in 2013. The South African National Biodiversity Institute (SANBI), through its National Wetland Inventory project, initiated a collaborative process to develop a classification by which wetland habitat types with shared natural attributes can be grouped together. The classification system is intended to be used throughout the country for a number of different applications, with a view to provide wetland specialists, academics, government and other role players with a common language when distinguishing different types of wetlands for management and conservation purposes. The National Wetland Inventory maps are provided by SANBI through National Freshwater Ecosystem Priority Area (NFEPA) wetland maps, which classify the major wetlands and waterbodies in the country at a coarse spatial scale. The classification was applied to the wetlands included in the inventory‟s National Wetland Map after extensive field testing throughout the country and through the National Freshwater Ecosystem Priority Areas (NFEPA) project. The system comprises a hierarchical classification process of defining a wetland based on the principles of the hydro-geomorphic (HGM) approach at higher levels, with structural features being included at the finer levels (SANBI, 2009). For the purposes of this study Version 4 of the NWCS was used as baseline information, as per SANBI‟s BGIS interactive tool. The NWCS uses hydrological and geomorphological traits to distinguish the direct factors that influence wetland function. This is presented as a 6 tiered structure with four spatially nested primary levels that are applied in a hierarchical manner between different wetland types on the basis of these direct factors (SANBI, 2009).

» Level 1: distinguishes between marine, estuarine and inland ecosystems based on the degree of connectivity the systems have with the ocean.

» Level 2: categorises the regional wetland setting using a combination of biophysical attributes at the landscape level.

» Level 3: assesses the topographical position of inland wetlands. Level 4 concerns the hydrogeomorphic (HGM) units as defined as follows:

Landform- considering the shape and localised setting of the wetland;

Hydrological characteristics- nature of water movement into, through and out of the wetland; and

Hydrodynamics- the direction and strength of flow through the wetland.



The HGM unit is considered the focal point for NWCS as the upper levels mean to classify the broad bio-geographical context for grouping functional wetland units at the HGM level, whilst the lower levels provide more descriptive detail. Important rivers are also classified according to the NFEPA rivers maps. These rivers are considered Freshwater Ecosystem Priority Areas (FEPAs). FEPAs are strategic spatial priorities for conserving freshwater ecosystems and supporting sustainable use of water resources. FEPAs are an essential part of an equitable and sustainable water resource strategy meaning that they need to stay in a good condition to manage and conserve freshwater ecosystems, and to protect water resources for human use. This means that the areas should be supported by good planning, decision-making and management to ensure that human use does not impact on the aquatic ecosystem. 2.3.2 WET-Health and Present Ecological State Incorporation of the HGM approach in this system is significant as it has been adopted throughout aquatic assessment with regard to Present Ecological State and WET-Health assessments. These systems can then be easily integrated using the HGM approach in-line with Eco-classification process of river and wetland reserve determinations used by the Department of Water and Sanitation (DWS). The Ecological Reserve of a river or wetland is used by DWS to assess the water resource allocations when assessing water use licence applications (WULAs). The WET- range of tools were developed to assist those wishing to undertake wetland rehabilitation, in terms of current and future human activities in Environmental Impact Assessments (EIA) or the Present Ecological State (PES) of a wetland in an Ecological Reserve Determination (ERD). These tools were developed as part of a nine-year research programme on wetland management which was initiated in 2003 by the Water Research Commission (WRC) and a range of partners that examines wetland rehabilitation, wetland health and integrity and the sustainable use of wetlands (WRC Project No. K5/1408). As wetlands are formed under the influence of geology, hydrology and topography it is necessary to note these features when delineating a wetland.

» Geology: geology influences the formation of a wetland by geological obstructions such as erosion resistant rock or impervious material close to the surface forcing groundwater to move close to or onto the soil surface.

» Hydrology: the water transfer mechanisms such as source, movement and exit are important features of a wetland.

» Topography: the topography of the landscape influences the likelihood of whether a wetland will form. For instance, under the right conditions wetlands may form in floodplains, valley bottoms, hillslopes, depressions and coastal flats.



A range of „hydro-geomorphic‟ types can be defined by considering the above features. Six HGM units are defined for South African inland wetlands (SANBI, 2009):

Figure 2.1: The HGM types for South African Inland wetlands (SANBI, 2009). The materials and methods of WET-Health Wetland Management Series (Macfarlane et al., 2007) establish the current ecological health of a wetland. This assessment defines wetland health “as a measure of the deviation of wetlands structure and function from the wetland‟s natural reference condition” (Macfarlane et al., 2007). A Level 1 Rapid Assessment would involve evaluating specific indicators pertaining to three categories of hydrological, geomorphological and vegetation health (Figure 3.2). The purposes of WET-Health are to aid users to understand the ecological condition of the wetland and identify the causes of degradation. The assessment criteria and information are specific to South Africa. The three categories (hydrological, geomorphological and vegetation) are assessed by taking into account the extent, intensity and magnitude of an impact which then produces a health score. Evaluation scores within each category are then combined to produce an overall impact of activities on the wetland system which corresponds to a Present State health category that provides an impact score scale of 1-6 and associated health category (ecological state) from A-F (Table 3.1), based on Kleynhans (1996, 1999). Such categories represent natural, largely natural, moderately modified, largely modified, extensively modified, and critically modified. The WET-Health Assessment also considers the likely trajectory of change based on the threats to or vulnerability of a wetland. Five categories of the Trajectory of Change include: large improvement, slight improvement, remains the same, slight decline and rapid decline. Overall health of the wetland is then presented by the calculated Present Ecological State scores and the most likely Trajectory of Change.



Figure 2.2: The steps involved in the WET-Health Level 1 rapid assessment (MacFarlane et al. 2007).

Step 1: Divide the Wetland into HGM units

Step 2: Assess Hydrological Health of the Wetland

» Step 2A: Evaluate changes to water input characteristics from the

catchment

» Step 2B: Evaluate changes to water distribution & retention within

wetland

» Step 2C: Determine the hydrological impact score of the HGM unit based

on integrating the assessments from Steps 2A & 2B

» Step 2D: Determine the overall Present Hydrological State of the

wetland based on integrating scores from individual HGM units

» Step 2E: Assess the anticipated Trajectory Of Change of the Wetland

Hydrology

Step 3: Assess Geomorphological Health

» Step 3A: Determine the Present Geomorphic State of the individual HGM

units

» Step 3B: Determine the overall Present Geomorphic State of the

wetland based on integrating scores from individual HGM units

» Step 3C: Assess the anticipated Trajectory Of Change of the geomorphology of the wetland

Step 4: Assess Vegetation Health of the wetland

» Step 4A: Familiarisation with the general structure and composition of

wetland vegetation in the area

» Step 4B: Identify and estimate the extent of disturbance classes

» Step 4C: Assess the changes to vegetation composition in each class

and integrate these for the overall HGM unit

» Step 4D: Determine the Present Vegetation State based on integrating

scores from individual HGM units

» Step 4E: Assess the anticipated Trajectory of Change of wetland

vegetation

Step 5: Represent the health scores for the overall wetland



Table 2.1: Description of A – F ecological categories based on Kleynhans (1996, 1999).

PES Description Combined impact score

PES Category Level of disturbance

Unmodified, natural. 0-0.9 A

Protected systems; relatively untouched by human hands; no discharges or impoundments allowed

Largely natural with few modifications. A slight change in ecosystem processes is discernable and a small loss of natural habitats and biota may have taken place.

1-1.9 B

Some human-related disturbance, but mostly of low impact potential

Moderately modified. A moderate change in ecosystem processes and loss of natural habitats has taken place but the natural habitat remains predominantly intact

2-3.9 C

Multiple disturbances associated with need for socio-economic development, e.g. impoundment, habitat modification and water quality degradation Largely modified. A large

change in ecosystem processes and loss of natural habitat and biota and has occurred.

4-5.9 D

The change in ecosystem processes and loss of natural habitat and biota is great but some remaining natural habitat features are still recognizable.

6-7.9 E

Often characterized by high human densities or extensive resource exploitation. Management intervention is needed to improve health, e.g. to restore flow patterns, river habitats or water quality

Modifications have reached a critical level and the ecosystem processes have been modified completely with an almost complete loss of natural habitat and biota.

8 - 10 F



3 DESKTOP DESCRIPTION OF AQUATIC ENVIRONMENT Wetlands in the region were identified using:

» Satellite imagery (Google Earth); and

» NFEPA wetland shapefiles.

3.1 Wetlands The NFEPA classification combines the majority wetland vegetation group and level 4 of the NWCS, which describes the wetland landform, to produce a wetland type. These wetlands are also defined by the National Freshwater Ecosystem Priority Area (NFEPA). According to the NFEPA database, these wetlands fall within the Swartkop‟s Estuary system and should therefore be an extension of the estuary. However, the physical description (next chapter) indicates that these wetlands are no longer part of the estuary and have separated into discrete wetland systems due to:

a) Infilling to create a surface for the construction of the original Fish Water Flats WWTW has severed these areas from the estuarine system causing them to each form their own wetland systems.

b) Storm water runoff from industrial and road surface areas adding excess fresh water which would not naturally form part of these wetlands resulting in permanent wetland systems rather than fringe (temporary/tidal) estuarine systems.

Figure 3.1. NPEFA Classification of the water systems surrounding the existing Fish Water Flats WWTW where the biogas facility will be constructed



This image illustrates the delineated boundary of the Swartkop's Estuary. The NPEFA database clearly delineates the area surrounding, and within, the Fish Water Flats boundary as part of the estuarine system. However, as the next section will illustrate, this has been altered due to the original WWTW infrastructure. It is important to note that the proposed site (within the existing Fish Water Flats WWTW footprint) is within 1km of the coastal high water mark. This means that DEA: Oceans and Coasts should be consulted regarding the management authority of the wetland systems within the proposed development area.

Figure 3.2. 100 Year Floodline of Estuary indicating that the estuary does not reach the existing infrastructure or the proposed biogas facility location within the Fish Water Flats WWTW



4 PHYSICAL DESCRIPTION OF AQUATIC ENVIRONMENT

4.1 Collection of site data Information on the project area and surrounding environments was gathered in a single site visit in April 2016. The data gathering process involved ground truthing the desktop study, delineating wetlands and assessing the state of the environment. This included describing the following features:

» Possible impacts on the aquatic environment (Section 6); and

» Present Ecological State of the wetlands (using WET-Health) and watercourses.

4.2 Wetlands identified surrounding the Fish Water Flats WWTW site. The following wetlands were identified within 500m of the proposed biogas facility on the Fish Water Flats WWTW site.

Figure 4.1. Wetlands identified within the proximity of the construction activities for the proposed Biogas Facility within the footprint of the Fish Water Flats WWTW



4.2.1 Wetland 1 Wetland 1 is situated to the west of the proposed biogas facility on the boundary of the Fish Water Flats WWTW. This wetland system has been severed from the Swartkop‟s Estuary by infilling and depositing of material from the original Fish Water Flats WWTW construction. This wetland‟s natural salinity has been diluted significantly by freshwater ingress due to runoff from the surrounding infrastructure (Fish Water Flats WWTW and the R102 road). This wetland can be classified as a floodplain wetland which was once an extension of the Swartkop‟s estuarine system. The permanent area (as per Figure 5.1) of wetland 1 contains a deep channel which runs through the centre of the wetland system. This channel is fed by the surrounding stormwater drainage systems from the road and the nearby WWTW. The temporary system is an extension of the estuary and the permanent wetland and contains both wetland and estuarine species. 4.2.2 Wetland 2 Wetland 2 is situated to the east of the proposed biogas facility, adjacent to the selected biogas location within the boundary of the Fish Water Flats WWTW. This wetland system has been severed from the Swartkop‟s Estuary by infilling and depositing of material from the original Fish Water Flats WWTW construction. This wetland‟s natural salinity has been diluted significantly by freshwater ingress due to runoff from the surrounding infrastructure (Fish Water Flats WWTW and the N2 road). This wetland can be classified as a depression wetland which was once a temporary extension of the Swartkop‟s estuarine system, but has now formed a separate system due to construction facilities related to the surrounding infrastructure. The permanent area (as per Figure 5.1) of wetland 2 contains standing water as a result of runoff from the surrounding stormwater drainage systems (N2 and WWTW). The temporary system is due to seasonal changes in the runoff of the surrounding infrastructure.

HYDROLOGY GEOMORPHOLOGY VEGETATION

WETLAND 1 Floodplain

Wetland

3.0 C 4.5 D 1.5 B

WETLAND 2 Depression

Wetland

3.8 C 4.5 D 1.5 B



4.2.3 Photographs of Wetland 1 & 2 Wetland 1

a) View of the temporary section of the wetland

b) View of the main stream of wetland 1 illustrating how

the wetland has been cut off (and fenced off) from the estuary

c) View of the infilling which severed the wetland from

the Swartkop‟s Estuary

d) Wetland 1 vegetation view

Wetland 2

a) View 1 of the depression wetland which has

formed adjacent to the WWTW and the estuary, note the banks which were created (by infilling) in order to construct the original WWTW

b) View 2 of the depression wetland which has

formed adjacent to the WWTW and the estuary, note the banks which were created (by infilling) in order to construct the original WWTW



c) View of the infrastructure constructed on site,

note the infilling which took place to level the site for construction

d) View of one of the roads which surround the

site, note that the wetland was severed from the full estuarine system

4.3 Present Ecological State (PES) 4.3.1 Hydrology The mean annual precipitation of the area is 526 mm per annum, with a peak rainfall in August. These wetlands have both been formed due to a change is the water table and surface water availability caused by storm water drainage from existing infrastructure (such as roads and concrete industrial surfaces) and due to the presence of the Swartkop Estuary. These wetlands have naturalised over time and have developed a plant profile which indicate that they are functional and permanent wetlands. The wetlands have been severed from the full Estuarine system due to existing infrastructure. This has impacted on the natural flow regime of these wetlands as they no longer receive periodic inflows of salt water from the estuary. The hydrological health score was assessed as 3.0 (Wetland 1) and 3.8 (Wetland 2) with a PES Hydrology Category of C, indicating that the hydrological integrity of the wetlands have been noticeably impacted, but not to the extent that it has caused the wetlands hydrological integrity to cease to function. The wetlands have naturalised to predominantly freshwater systems.

DESCRIPTION IMPACT SCORE

RANGE HEALTH

CATEGORY

No discernible modifications, or the modifications are of such a nature that they have no impact on the hydrological integrity.

0-0.9 A

Although identifiable, the impact of the modifications on the hydrological integrity are small.

1-1.9 B

The impact of the modifications on the hydrological integrity is clearly identifiable, but limited.

2-3.9 C

The impact of the modifications is clearly detrimental to the hydrological integrity. Approximately 50% of the hydrological integrity has been lost.

4-5.9 D

Modifications clearly have an adverse effect on the hydrological integrity. 51% to 79% of the hydrological integrity has been lost.

6-7.9 E

Modifications are so great that the hydrological functioning has been drastically altered. 80% or more of the hydrological integrity has been lost.

8 - 10 F



4.3.2 Geomorphology The geomorphological health of the two wetlands was considered to be moderately modified. Both wetlands have been altered due to the surrounding infrastructure (existing) which has severed much of their estuarine influence. The wetlands have naturalised over time and resemble wetlands rather than being extensions of the Swartkop‟s Estuary. Wetland 1 and Wetland 2 have therefore been given a score of 4.5 with a PES Geomorphology Category of D, indicating that the wetlands have been noticeably altered due to changes which were made when the original roads and Fishwater Flats WWTW infrastructure was constructed.

DESCRIPTION IMPACT SCORE

PRESENT GEOMORPHIC

STATE CATEGORY

Unmodified, natural. 0-0.9 A

Largely natural with few modifications. A slight change in geomorphic processes is discernible but the system remains largely intact

1-1.9 B

Moderately modified. A moderate change in geomorphic processes has taken place but the system remains predominantly intact

2-3.9 C

Largely modified. A large change in geomorphic processes has occurred and the system is appreciably altered.

4-5.9 D

Greatly modified. The change in geomorphic processes is great but some features are still recognisable

6-7.9 E

Modifications have reached a critical level as geomorphic processes have been modified completely

8-10 F

4.3.3 Vegetation The vegetation within both of the wetlands consisted of a vegetation profile of permanent wetland species as well as a small number of estuarine species due to the slight presence of salinity in the outlying (temporary) areas of the wetlands. The impact score has been assessed as 1.5, with a PES Vegetation Category of B. The vegetation category has not been classified as natural due to the influence of infrastructure on the wetlands which should essentially form part of the greater estuarine system. These wetlands have naturalised over time and desalinified due to being severed from the estuarine system which has resulted in the naturalisation of a full and dominant freshwater wetland species profile.

DESCRIPTION IMPACT SCORE PRESENT

VEGETATION STATE CATEGORY

Vegetation composition appears natural. 0-0.9 A

A very minor change to vegetation composition is evident at the site.

1 - 1.9 B

Vegetation composition has been moderately altered but introduced alien and/or ruderal species are still clearly less abundant than characteristic indigenous wetland species.

1 - 3.9 C

Vegetation composition has been largely altered and introduced alien and/or ruderal species occur in approximately equal abundance to the characteristic indigenous wetland species.

4 - 5.9 D



Vegetation composition has been substantially altered but some characteristic species remain, although the vegetation consists mainly of introduced, alien and/or ruderal species.

6 - 7.9 E

Vegetation composition has been totally or almost totally altered, and if any characteristic species still remain, their extent is very low.

8 - 10 F



5 IDENTIFIED IMPACTS OF THE FISH WATER FLATS WWTW BIOGAS FACILITY

The following section describes the impacts which the activity (construction of biogas facility within 500m of wetlands) will have on the identified and delineated wetland systems. Figure 6.1 illustrates the wetlands which have been delineated within the proximity of the existing WWTW. Please note that the biogas facility will be constructed within the footprint of the existing WWTW.

Figure 5.1. Wetlands identified within the proximity of the construction activities for the proposed Biogas Facility within the footprint of the Fish Water Flats WWTW

5.1 Identification of potential impacts The proposed biogas facility may have the following impacts on the surrounding wetland systems. These impacts must be mitigated for to ensure that the already impacted upon wetland systems do not endure further deterioration. 5.1.1 Sedimentation

Nature: The construction facility within the immediate vicinity of wetland 2 may lead to sedimentation of the wetland system. The removal of existing infrastructure, vegetation and top soil layers to prepare for the biogas facility, as well as the new exposed surface area will leave large areas exposed to the elements (wind and rain), causing runoff of sediments into the wetland system. Sediments may smother benthic habitats within the wetland system and lead to changes in flow patterns, vegetation distribution and overall wetland functionality. Wetland 1 will not be impacted by potential sedimentation.

Without mitigation With mitigation

Extent Localised Localised



Duration Permanent Short

Magnitude Very high Moderate

Probability Highly probable Unlikely

Significance High Low

Status (positive/negative) Negative Negative

Reversibility Low High

Irreplaceable loss of resources?

No No

Can impacts be mitigated Yes

Mitigation:

» A storm water management plan must be implemented to ensure that construction activities do not impact on the wetland system. Areas of surface runoff should be managed with a storm water management plan.The use of cut-off drains and/or berms may be required to prevent the loss of soil into the wetland.

» During construction, erosion should be monitored while areas of vegetation are cleared. The cleared areas must be re-vegetated as soon as possible to prevent excessive runoff.

Cumulative Impacts: The mismanagement of exposed soil during the construction period could lead to the sedimentation of the nearby wetland. This could have significant impacts on the ecological state of the wetland and could reduce water flow and alter vegetation profiles.

Residual Impacts: Long term sedimentation could result in the collapse of the wetland system.

5.1.2 Alteration of the environment beyond the development footprint

Nature: The construction of the biogas facility could result in construction “sprawl” beyond the intended (and existing) footprint. This could lead to the inadvertent alteration of the wetland system (wetland 2) beyond the construction footprint. The effect of alterations beyond the specified construction area could result in the additional and unaccounted for loss of species, the destruction of the wetland habitat and erosion. Wetland 1 is a significant distance from the proposed construction site, and is unlikely to be impacted by construction.




Magnitude Very High Low

Probability Improbable Very improbable

Significance Moderate Low

Status (positive/negative) Negative Neutral

Reversibility Low Low


Yes No


Mitigation:

» The construction site must be demarcated prior to the commencement of construction.

» A storm water management plan must be implemented to ensure that construction activities do not impact on the wetland system. Areas of surface runoff should be managed with a storm water management plan.

» The use of cut-off drains and/or berms may be required to prevent the loss of soil into the wetland.

» Ensure that the construction footprint is limited to just what is needed in order to reduce the amount of vegetation which would need to be cleared thereby limiting the available area for “sprawl”.

» An alien vegetation plan must be implemented to ensure that alien vegetation does not encroach on the wetland system.



Cumulative Impacts: The cumulative impacts of the addition of a biogas facility within an area which has already been significantly transformed could have damaging effects on the wetland system due to an intensified impact footprint. Without mitigation the effect could compound the loss of species of special concern as the plant search and rescue will not include outlying areas. This could also have a cumulative impact on soil erosion and sedimentation.

Residual Impacts: The destruction of vegetation and the wetland system beyond the development footprint could have lasting erosion and sedimentation effects.

5.1.3 Pollution of Wetland Systems

Nature: Various substances may result in the pollution of the wetland system (wetland 2). Pollution from litter and general construction waste may occur due to improper site management. Washing down of vehicles and equipment may result in the pollution of the stormwater drainage areas which feed the wetland systems. During the operational phase of the proposed biogas plant (as well as the alternative new Zimpro® plant) there is the continuous risk of sewage or waste water leaking or spilling over and polluting the wetland systems. It is highly unlikely that wetland 1 will be impacted due to its significant distance from the proposed biogas plant site.




Magnitude Very high Moderate

Probability Highly probable Unlikely

Significance High Low

Status (positive/negative) Negative Negative

Reversibility Low High


No No


Mitigation:

» A storm water management plan must be implemented to ensure that the wetland systems do not receive polluted water or runoff during the construction and operational phases of the proposed biogas facility.

» Emergency rehabilitation steps must be put in place should the biogas plant leak or spill into the wetland systems.

Cumulative Impacts: The compounded pollution into the greater Swartkop‟s River Estuary system (including the two delineated wetlands) could lead to a loss of estuarine and wetland species. Estuarine and wetland systems are integral components of species conservation and must be managed as extremely sensitive ecosystems.

Residual Impacts: Long term pollution of the wetland systems could result in loss of species and could potentially collapse the entire wetland system.



6 CONCLUSIONS AND RECOMMENDATIONS The potential impacts of the proposed Fish Water Flats WWTW Biogas Facility (including the associated infrastructure) are moderate (with mitigation). A comprehensive storm water management plan must be put in place to prevent sedimentationand pollution of the wetland system. This is particularly important for wetland 2, which is in close proximity to the construction site.. The Department of Environmental Affairs (DEA): Oceans and Coasts must be consulted due to the fact that these wetland systems form part of the greater Swartkop‟s estuarine system.

The impacts on the surrounding wetlands are moderate (with mitigation) and do not present a fatal flaw to the proposed Biogas Facility.



7 REFERENCES Breen, C.M. and Begg, G.W., (1989). Conservation status of southern African Wetlands. In: Biotic diversity in Southern Africa; Concepts and conservation, ed BJ Huntley. Oxford University Press, Cape Town Davies, B. and Day J. (1998). Vanishing Waters. University of Cape Town Press. Department of Water Affairs and Forestry - DWAF (2005). A practical field procedure for identification and delineation of wetland and riparian areas Edition 1. Department of Water Affairs and Forestry , Pretoria. Department of Water Affairs and Forestry (1999).Resource Directed Measures for Protection of Water Resources: Wetland Ecosystems.Resource Quality Services, Department of Water Affairs and Forestry, Pretoria, South Africa. Ewart-Smith, J.L., Ollis D.J., Day J.A. and Malan, H.L. (2006). National Wetland Inventory: Development of a Wetland Classification System for South Africa. WRC Report No. KV 174/06. Water Research Commission, Pretoria IUCN, (1980). World Conservation strategy: Living resource conservation for sustainable development. Jolly, J. (1983). A Geohydrological Evaluation: Bushmans River Mouth – Cape Padrone. Technical Report No. GH3262 (Unpubl.), Dept of Water Affairs, 46pp. Kleynhans, C.J. (1996). A qualitative procedure for the assessment of the habitat integrity status of the Luvuvhu River. Journal of Aquatic Ecosystem Health 5: 41 - 54. Kleynhans, C.J. (1999). A procedure for the determination of the ecological reserve for the purposes of the national water balance model for South African Rivers. Institute for Water Quality Studies. Department of Water Affairs and Forestry, Pretoria. Kotze, D.C., Marneweck, G.C., Batchelor, A.L., Lindley, D.S. and Collins, N. (2008). WET-EcoServices A technique for rapidly assessing ecosystem services supplied by wetlands. WRC Report No: TT 339/08 Macfarlane, D.M., Kotze D.C., Ellery, W.N., Walters, D., Koopman, V., Goodman, P., Goge, C., (2007).WET-Health: A technique for rapidly assessing wetland health. WRC Report TT 340/08, Water Research Commission, Pretoria Mouton, E. (2004). Investigation into the hydrogeological potential of the Albany coast area. Technical Report No. WE03103 (Unpubl.), Dept of Water Affairs, 117pp. National Water Act, 1998 (Act No. 36 of 1998), as amended Nel, J., Maree, G., Roux, D., Moolman, J., Kleynhans, N., Silberbauer, M. and Driver, A. (2004). South African National Spatial Biodiversity Assessment 2004: Technical Report. Volume 2: River Component. CSIR Report Number ENV-S-I-2004-063. Council for Scientific and Industrial Research, Stellenbosch Nickall, E.S. (2008). The feasibility of Artificial Recharge of the Bushmans River Mouth Aquifer. Unpublished MSc Thesis, Dept of Geology, NMMU SANBI (2009). Further Development of a Proposed National Wetland Classification System for South Africa. Primary Project Report. Prepared by the Freshwater Consulting Group (FCG) for the South African National Biodiversity Institute (SANBI).



Smit, L., and Wiseman, K. (2001). Environmental resource economics as a tool for environmental management in the City of Cape Town. Pages 190-218 in Forum for Economics and Environment: first conference proceedings. Available online at:http://www.econ4env.co.za/archives/ecodivide/Theme4e.pdf Terer, T.G., Ndiritu, G. and Gichuki, N.N. (2004). Socio-economic values and traditional strategies of managing wetland resources in Lower Tana River, Kenya. Hydrobiologia 527:3-14.

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