Aquatic ecosystem delineation and recommendations for aquatic ecosystem improvement of

63 Pages·2015·6.65 MB·English

Aquatic ecosystem delineation and
recommendations for aquatic ecosystem
improvement

of

A PORTION OF PORTION 33 OF THE FARM
BRAAMFONTEIN 53 IR
(ALSO KNOWN AS WESTDENE DAM)

March 2015

Compiled by: Mr Bertus Fourie (M.Sc. Aquatic Health, Cert. Sci. Nat)
Report reviewed by: Dr. A.C. Kemp (Ph.D., Pr.Sci.Nat. (Zoology & Ecology))
Aquatic ecosystem Report: Westdene Dam March 2015 1 of 63 pages
DECLARATION OF INDEPENDENCE

I, Bertus Fourie, declare that -
I am subcontracted as specialist consultant by Galago Environmental cc. for the
aquatic ecosystem delineation.
I will perform the work relating to the application in an objective manner, even if this
results in views and findings that are not favourable to the applicant;
I declare that there are no circumstances that may compromise my objectivity in
performing such work;
I have expertise in conducting the specialist report relevant to this application,
including knowledge of the National Environmental Management Act, 1998 (Act No.
107 of 1998), regulations and any guidelines that have relevance to the proposed
activity; I will comply with the Act, regulations and all other applicable legislation;
I will take into account, to the extent possible, the matters listed in Regulation 8;
I have no, and will not engage in, conflicting interests in the undertaking of the
activity;
I undertake to disclose to the applicant and the competent authority all material
information in my possession that reasonably has or may have the potential of
influencing - any decision to be taken with respect to the application by the
competent authority; and - the objectivity of any report, plan or document to be
prepared by myself for submission to the competent authority;
All the particulars furnished by me in this form are true and correct; and
I realise that a false declaration is an offence in terms of Regulation 71 and is
punishable in terms of section 24F of the Act.

Bertus Fourie
SACNASP Reg. No: 300025/13
COPYRIGHT
Copyright to the text and other matter, including the manner of presentation, is the
exclusively the property of the author. It is a criminal offence to reproduce and/or use,
without written consent, any matter, technical procedure, and/or technique contained in this
document. Criminal and civil proceedings will be taken as a matter of strict routine against
any person and/or institution infringing the copyright of the author and/or proprietors.
Aquatic ecosystem Report: Westdene Dam March 2015 2 of 63 pages
DECLARATION OF INDEPENDENCE OF REVIEWER

Bertus Fourie is a trained wetland/riparian delineator and wetland impact assessor as in
line with the Gauteng Department of Agriculture and Rural Development (GDARD) and
he is registered as a Certificated Natural Scientist (Ecological Science) with the S.A.
Council for Natural Scientific Professions. This communication serves to verify that the
wetland report compiled by Mr Fourie has been prepared according to the DWA
guidelines and I have verified and reviewed the contents thereof.

I, declare that I:
 abide by the Code of Ethics of the S.A. Council for Natural Scientific Professions;
 act as an independent specialist consultant in the fields of Zoology and Ecology;
 have expertise in conducting specialist reports relevant to this application, including
knowledge of the National Environmental Management Act, 1998 (Act No. 107 of
1998), regulations and any guidelines that have relevance to the proposed activity;
 am subcontracted as specialist consultant by Galago Environmental CC for the
review of the aquatic report and rehabilitation plan for the Westdene Dam as
described in this report;
 have no financial interest in the proposed development other than remuneration for
work performed;
 neither have nor will have any vested or conflicting interests in the proposed
development;
 undertake to disclose to Galago Environmental CC and its client, and the competent
authority, any material information that has or may have the potential to influence
decisions by the competent authority as required in terms of the Environmental
Impact Assessment Regulations 2006.

Dr. A.C. Kemp
Aquatic ecosystem Report: Westdene Dam March 2015 3 of 63 pages
TABLE OF CONTENTS

1. INTRODUCTION ............................................................................................. 10
1.1. BUFFERS AS PER GDARD GUIDELINES.......................................................... 13
1.2. SCOPE OF WORK ......................................................................................... 14
2. ASSUMPTIONS AND LIMITATIONS .............................................................. 14
3. SITE LOCATION AND DESCRIPTION ........................................................... 16
3.1. PROPOSED DEVELOPMENT ........................................................................... 16
3.2. REGIONAL VEGETATION ................................................................................ 16
3.3. GEOLOGY AND LAND TYPES .......................................................................... 17
3.4. AQUATIC DESCRIPTION ................................................................................. 17
3.4.1. Primary boundary determinants: ......................................................... 18
3.4.2. General: .............................................................................................. 18
3.4.3. Climatic conditions on the Site ............................................................ 19
3.5. HISTORICAL AND CURRENT USE OF THE PROPERTY ........................................ 19
3.6. WETLAND INVENTORIES................................................................................ 24
3.7. NATIONAL FRESHWATER ECOSYSTEM PRIORITY AREAS (NFEPA) INVENTORY . 24
4. METHODS FOR CLASSIFICATION OF AQUATIC ECOSYSTEM, THE
DELINEATION AND PRESENT ECOLOGICAL STATE (PES) CALCULATION . 25
4.1. CLASSIFICATION OF AQUATIC ECOSYSTEMS .................................................... 25
4.2. WETLAND DELINEATION METHODS ................................................................ 25
4.3. DELINEATION OF RIPARIAN EDGE ................................................................... 27
4.4. WETLAND PRESENT ECOLOGICAL STATE (PES) CALCULATION METHOD ........... 27
4.5. RIPARIAN PRESENT ECOLOGICAL STATE (PES) CALCULATION METHOD ........... 28
4.6. WETLAND ECOLOGICAL SERVICES (WET-ECOSERVICES)............................... 29
4.7. ECOLOGICAL IMPORTANCE AND SENSITIVITY (EIS) CALCULATION ..................... 29
4.8. AQUATIC MACRO INVERTEBRATES ................................................................. 30
4.9. WATER QUALITY .......................................................................................... 32
4.10. FISH SAMPLING ............................................................................................ 32
4.11. SECCHI DISK AND DEPTH PROFILING .............................................................. 33
5. RESULTS ........................................................................................................ 33
5.1. PRESENT ECOLOGICAL SCORE & ECOLOGICAL IMPORTANCE AND SENSITIVITY . 36
5.1.1. PES calculations ................................................................................. 36
5.1.2. Wetland Ecological Services (WET-EcoServices) .............................. 36
5.1.3. Ecological Importance and Sensitivity ................................................ 38
5.2. MACRO-INVERTEBRATES ASSESSMENT .......................................................... 40
5.3. FISH SAMPLING ............................................................................................ 41
5.4. SECCHI DISK AND DEPTH RESULTS ................................................................ 41
5.4.1. Secchi disk depth results .................................................................... 42
5.4.2. Depth assessments ............................................................................ 44
5.5. WATER QUALITY PARAMETERS ...................................................................... 46
6. DISCUSSION, IMPACT ASSESSMENT AND GENERAL MITIGATION
MEASURES ........................................................................................................... 47
6.1. ECOLOGICAL SUPPORT ZONES ...................................................................... 49
6.1.1. Water quality improvements ............................................................... 49
6.1.2. Phytoremediation ................................................................................ 49
6.1.3. Replanting of hydrophytes in shallow areas ....................................... 51
6.1.4. Dam shoreline stabilisation ................................................................. 53
6.1.5. Storm water release points ................................................................. 54
Aquatic ecosystem Report: Westdene Dam March 2015 4 of 63 pages
6.1.6. Litter nets/ traps .................................................................................. 55
6.2. RECREATIONAL ZONE ................................................................................... 56
6.2.1. Fishing ................................................................................................ 56
6.2.2. Paddling or Rowing on the dam .......................................................... 57
6.3. GENERAL MITIGATION MEASURES .................................................................. 57
7. CONCLUSION AND RECOMMENDATIONS.................................................. 59
7.1. ENVIRONMENTAL LAWS ................................................................................ 60
8. REFERENCES ................................................................................................ 61

FIGURES:
FIGURE 1: THE TYPES AND LOCATION OF INLAND AQUATIC ECOSYSTEMS (OLLIS, ET AL., 2013) 11
FIGURE 2: SKETCH INDICATING A CROSS SECTION OF RIPARIAN ZONATION COMMONLY FOUND IN
SOUTH AFRICA – WWW.EPA.GOV/ .................................................................................. 13
FIGURE 3: LOCALITY MAP OF THE STUDY AREA ...................................................................... 16
FIGURE 4: LAND TYPES OF THE STUDY SITE .......................................................................... 17
FIGURE 5: THE CATCHMENT AND HYDROLOGICAL DATA FOR THE STUDY SITE, AS AVAILABLE
FROM DWA RQS SERVICES. ......................................................................................... 18
FIGURE 6: THE MOST RECENT GOOGLE EARTH AERIAL IMAGE OF THE SITE FROM 2014 ........... 20
FIGURE 7: THE OLDEST USABLE GOOGLE EARTH IMAGE OF THE SITE, TAKEN IN 2002 .............. 20
FIGURE 8: THE 1938 IMAGE OF THE SITE .............................................................................. 21
FIGURE 9: THE 1954 IMAGE OF THE SITE .............................................................................. 22
FIGURE 10: THE 1964 IMAGE OF THE SITE ............................................................................ 22
FIGURE 11: THE 1975 IMAGE OF THE SITE ............................................................................ 23
FIGURE 12: THE 1982 IMAGE OF THE SITE ............................................................................ 23
FIGURE 13: THE COJ WETLAND INVENTORY MAP OF THE STUDY SITE ..................................... 24
FIGURE 14: THE NFEPA INFORMATION FOR THE STUDY SITE ................................................. 24
FIGURE 15: DESCRIPTION OF THE TOPOGRAPHY OF AN AREA (FROM DWAF, 2005) ................ 26
FIGURE 16: CROSS SECTION THROUGH A WETLAND .............................................................. 26
FIGURE 17: LOCATION OF WATER QUALITY SAMPLE SITES ..................................................... 32
FIGURE 18: THE AQUATIC ECOSYSTEMS OF THE STUDY SITE .................................................. 34
FIGURE 19: THE DAM WALL .................................................................................................. 35
FIGURE 20: THE LOCATION OF THE ISLAND IN THE MIDDLE OF THE DAM ................................... 35
FIGURE 21: A STORM WATER OUTLET DIRECTLY INTO THE DAM .............................................. 36
FIGURE 22: WET-ECOSERVICES FOR THE WETLAND SPIDER GRAPH ...................................... 37
FIGURE 23: DATA BAR COLOUR SCALE OF THE RESULTS FOR THE WET-ECOSERVICES ........... 38
FIGURE 24: SECCHI AND DEPTH SAMPLE SITE LOCATION ........................................................ 42
FIGURE 25: SECCHI DISK DEPTH RESULTS ............................................................................ 43
FIGURE 26: SECCHI DISK DEPTH AREAS ................................................................................ 43
FIGURE 27: DEPTH RESULTS ............................................................................................... 45
FIGURE 28: DEPTH AREAS ................................................................................................... 45
FIGURE 29: DIFFERENCES BETWEEN RESTORATION, REHABILITATION AND REMEDIATION IN
TERMS OF ECOSYSTEMS (LOVETT & EDGAR, 2002). ....................................................... 47
FIGURE 30: FUNCTIONAL DIVISION OF THE DAM ..................................................................... 48
FIGURE 31: A TYPICAL PHYTOREMEDIATION FRAME ............................................................... 50
FIGURE 32: BASIC DESIGN OF FLOATING WETLANDS .............................................................. 50
FIGURE 33: A TYPICAL SHALLOW AREA ................................................................................. 52
FIGURE 34: LOCATION OF SHALLOW AREAS FOR PLANTING OF HYDROPHYTES ......................... 52
FIGURE 35: ILLUSTRATION OF THE CURRENT SHORE CONDITIONS........................................... 53
FIGURE 36: THE USE OF RIPRAP ON THE SHORE EDGES ........................................................ 53
FIGURE 37: RESHAPING OF THE SHORE AND PLANTING OF HYDROPHYTES .............................. 54
FIGURE 38: TYPICAL CURRENT STORM WATER OUTLET STRUCTURE ....................................... 55
FIGURE 39: A SECTION OF THE ARTIFICIAL WETLAND WITH DIFFERENT FAUNAL HABITAT ZONES 55
FIGURE 40: EXAMPLE OF A FISHING TACKLE DISPOSAL TUBE .................................................. 57
Aquatic ecosystem Report: Westdene Dam March 2015 5 of 63 pages
TABLES:
TABLE 1: BUFFER REQUIREMENTS AS PER GDARD, 2014 ..................................................... 13
TABLE 2: THE DESCRIPTION OF THE HEALTH CATEGORY ......................................................... 28
TABLE 3: EIS INTERPRETATION GUIDE .................................................................................. 30
TABLE 4: THE EIS SCORE OF WETLAND#1 AND REMC CLASSIFICATION ................................. 39
TABLE 5: LIST OF AQUATIC MACROINVERTEBRATES AND THE SENSITIVITIES OF THE ORGANISMS
TO WATER QUALITY ....................................................................................................... 40
TABLE 6: FISH SPECIES OBSERVED DURING THE SITE VISIT .................................................... 41
TABLE 7: FULL CONTACT RECREATION: EFFECT OF WATER CLARITY ON AESTHETIC AND HUMAN
HEALTH ........................................................................................................................ 44
TABLE 8: THE WATER QUALITY RESULTS OF THE SAMPLE SITES. DATA COLOUR BARS INDICATE
OUTLIERS (WHITE = MEAN, GREEN< MEAN AND RED > MEAN) ........................................... 46
TABLE 9: THE DIFFERENCE BETWEEN REHABILITATION, REMEDIATION AND RESTORATION ........ 47

Aquatic ecosystem Report: Westdene Dam March 2015 6 of 63 pages
Glossary of terms:
Buffer zone- The area of land next to a body of water, where activities such as
construction are restricted in order to protect the water.
Detritus- Decaying organic matter found in the top layer of soil or mixed with wetland
waters; a food source for many small wetland organisms.
Endangered species- Any species of plant or animal that is having trouble surviving and
reproducing. This is often caused by loss of habitat, not enough food, or
pollution. Endangered species are protected by the government in an effort to
keep them from becoming extinct.
Ecosystem- A network of plants and animals that live together and depend on each other
for survival.
Emergent- Soft stemmed plants that grow above the water level.
Erosion- Process in which land is worn away by external forces, such as wind, water, or
human activity.
Freshwater- Water without salt, like ponds and streams.
Gleyed soil- Mineral wetland soil that is or was always wet; this results in soil colours of
grey, greenish grey, or bluish grey.
Habitat- The environment in which an organism lives.
Hydric soil- Soil that is wet long enough for anoxic (oxygenless) conditions to develop. The
water in the soil forces air out. This soil type is found in wetlands.
Hydrocarbon Oils, fuels and paints made using fossil fuels (including crude oils, coal etc.)
Hydrophyte- A plant, which grows in water.
Mesotrophic soil- Soils with a moderate inherent fertility. An indicator of soil fertility is its
base status, which is expressed as a ratio relating the major nutrient cations
(calcium, magnesium, potassium and sodium) found there to the soil's clay
percentage.
Organic material- Anything that is living or was living; in soil it is usually made up of nuts,
leaves, twigs, bark, etc.
Organism- A living thing.
Peat- Organic material (leaves, bark, nuts) that has decayed partially. It is dark brown with
identifiable plant parts, and can be found in peatlands and bogs.
Pollution- Waste, often made by humans, that damages the water, the air, and the soil.
Precipitation- Rain, sleet, hail, snow.
Riparian- Riparian habitat includes the physical structure and associated vegetation of the
areas associated with a watercourse which are commonly characterized by
alluvial soils, and which are inundated or flooded to an extent and with a
Aquatic ecosystem Report: Westdene Dam March 2015 7 of 63 pages
frequency sufficient to support vegetation of species with a composition and
physical structure distinct from those of adjacent land areas
Redoximorphic conditions- a soil property, associated with wetness, which results from
the reduction and oxidation of iron and manganese compounds in the soil after
saturation with water and desaturation, respectively. Mottling are common
redoximorphic features of soils.
Runoff- Rainwater that flows over the land and into streams and lakes; it often picks up soil
particles along the way and brings them into the streams and lakes.
Salinity- The amount of salt in water.
Saturation-The condition in which soil contains as much water as it can hold.
Silt- One of three main parts of soil (sand, silt, and clay); silt is small rock particles that are
between .05 mm and .002 mm in diameter.
Submerged aquatic vegetation- Plants that live entirely under water.
Top soil- The top layer of soil; it is full of organic material and good for growing crops.
Water table- The highest level of soil that is saturated by water.
Watershed - All the water from precipitation (rain, snow, etc.) that drains into a particular
body of water (stream, pond, river, bay, etc.)
Wetland- 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.”

Acronyms:

AECO Aquatic Environmental Control Officer
ASPT Average Score Per Taxon
CERM Comprehensive Ecological Reserve Methodology
DSS Decision Support System
DWA Department of Water Affairs
DWS Department of water and sanitation
EC Ecological Category
ECO Environmental control officer
EIS Ecological Importance and Sensitivity
EWR Environmental Water Requirements
Aquatic ecosystem Report: Westdene Dam March 2015 8 of 63 pages
FRAI Fish Response Assessment Index
FROC Fish reference of occurrence
GSM Gravel, Sand, Mud
GDARD Gauteng Department of Agriculture and Rural Development
IERM Intermediate Ecological Reserve Methodology
IHAS Invertebrate Habitat Assessment System
IHI Index of Habitat Integrity
MIRAI Macro-Invertebrate Response Assessment Index
MVIC Marginal Vegetation in Current
MVOOC Marginal Vegetation out of Current
NFEPA National Freshwater Ecosystem Priority Areas
PES Present Ecological State
REC Recommended Ecological Category
REMC Recommended Ecological Management Class
RERM Rapid Ecological Reserve Methodology
RHP River Health Programme
SASS5 South African Scoring System (Version 5)
SIC Stones in current
SOG Soap, oil and grease
SOOC Stones out of current
TPH Total petroleum hydrocarbons
TWQR Target water quality range
VEGRAI Vegetation Response Assessment Index
Wetland IHI Wetland index of habitat integrity tool
WMA Water Management Area
WUL Water use licence (approved license)
WULA Water use licence application (license application)
Aquatic ecosystem Report: Westdene Dam March 2015 9 of 63 pages
1. Introduction
Galago Environmental CC was appointed to delineate possible edges of aquatic
ecosystems (including riparian and wetland areas) for a Portion of Portion 33 of the Farm
Braamfontein 53 IR (henceforth known as the Westdene Dam or “study site”). The
investigation into the possible occurrence of wetlands on the neighbouring properties (up to
500 meters extended study area (ESA)), in terms of General Notice 1199 of the National
Water Act (Act 36 of 1998) was also done (albeit desktop derived). Included in the scope of
work were proposals for mitigation measures to ensure that optimum riparian and wetland
functioning is retained.

An aquatic ecosystem is defined as “an ecosystem that is permanently or periodically
inundated by flowing or standing water or which has soils that are permanently or
periodically saturated within 0.5m of the soil surface” (Ollis et al. 2013). This term is further
defined by the definition of a watercourse. In the National Water Act, 1998 (Act No. 98 of
1998) a watercourse is defined as:
(a) A river or spring;
(b) A natural channel in which water flows regularly or intermittently;
(c) A wetland, lake or dam into which, or from which, water flows; and
(d) Any collection of water which the Minister may, by notice in the Gazette,
declare to be a watercourse and a reference to a watercourse includes, where
relevant, its bed and banks;

Different inland (freshwater) watercourses occur in South Africa and are defined by their
topographical location, water source, hydroperiod, soils, vegetation and functional units
(Ollis, et al., 2013). The following illustration presents the types and typical locations of
different inland aquatic systems found in South Africa (Figure 1).

Aquatic ecosystem Report: Westdene Dam March 2015 10 of 63 pages