HARTBEESPOORT DAM INTEGRATED BIOLOGICAL

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HARTBEESPOORT DAM INTEGRATED BIOLOGICAL
REMEDIATION: INTRODUCTION OF WETLANDS, INSTREAM
AND SHORELINE HABITAT
*Petrus Venter and **Gill Ledger
*Department of Water Affairs (DWA) Crocodile West Marico Catchment Water
Management Area (WMA) – Acting Director North West: Regulation and Use
Harties Metsi a me “My Water” office, Private Bag X 356, Hartbeespoort 0216;
Tel no: (012) 207 9911; Fax no: (012) 207 9914; email: [email protected]
**[email protected]
Hartbeespoort Dam (HBPD) is situated within the North West Province, but is mainly
impacted by economic activities in the upper Gauteng part of it’s catchment, and has for
more than 35 years experienced toxic “blue green algae” (Cyanobacteria) blooms. The
hypertrophic state (high nutrient loads, mainly phosphates) originates from dense
urbanisation and industrialization in the upper catchment. This phenomenon also occurs in
most of the water bodies in the Crocodile Marico Water Management Area (WMA) and in
some other water bodies in the rest of South Africa. The upper Crocodile, Hennops,
Jukskei, Skeerpoort and Magalies rivers flow into HBPD. This is an increasing threat to
water bodies internationally which is compounded by global warming.
The Metsi a me Programme started in July 2006 as a result of close cooperation between
the Department of Water Affairs (DWA) and the North West Department of Agriculture,
Conservation, Environment and Rural Development (NWDACERD). The Integrated Metsi
a me Programme has several Key Focus Areas (KFA’s) grouped in sub programmes: (1)
the Dam Basin (operational), (2) Upper Catchment, (3) the Information, Communication
and Knowledge Centre Hubs, (4) Compliance and Enforcement with overarching
Programme Coordination.
The objectives, achievements, challenges and lessons learned during the past two years
of this highly challenging programme is presented. This extensive Integrated Programme
includes wetlands and biodiversity, in order to find the balance between 1) ever increasing
impacts, 2) sustainable development and 3) the protection and restoration of our water
resources.
The Projects
Amongst all the different dam basin and catchment KFA’s, these different wetland related
focus areas includes the optimising of aquatic ecosystem services of wetlands and Instream habitat, both upstream and within the dam basin.
This includes phytoremediation, bioremediation and hyperaccumulation principles
implemented in four KFA’s:
Floating wetlands;
Shoreline rehabilitation;
Natural wetlands and Artificial Functional Wetlands (AFW’s); and
In-stream Habitat stabilization and re-vegetation.
INTRODUCTION
Figure 1: HBPD wall showing algae and hyacinth trapped before the harvesting boom
Aims and Objectives Summary
Enhancing the functionality of the water resources, this includes the following:
1. Manipulation and increased species diversity (macrophyte and maco-invertebrate) to
obtain the desired food web structure through rehabilitation, restructuring, monitoring,
maintenance and management.
2. Optimization of nutrient recycling in foodwebs and biodiversity.
3. Cleaning, purifying and restoring of “life giving properties” in the water – thereby
improving the water quality, flow regime and erosion control – which will in turn assist
with the removal of unwanted excessive nutrients. In other words, unlocking and
maximizing the ecosystem services in nature.
4. Supplementation and enhancement of the shoreline and riparian vegetation by
remediation and artificial systems (floating wetlands) which was destroyed by the
construction and development of housing schemes, golf courses, boating and water
sports facilities as well as previous chemical control (hyacinth);
5. Storm-water reduction, dissipation, detention and retention – which will help with the
reducing of sediments in the system by reducing storm-water peak flows and aid with
the ground water infiltration.
6. The development and inclusion of a Shoreline littoral zone EcoClassification for
impoundments (e.g. HBPD pilot) into the Department of Water Affairs zoning
classification thereby extending the classification which exists for rivers and In-stream
habitat.
7. The development of Resource Quality Objectives (RQO’s) for inclusion in water use
authorisations for developers around the HBPD as well as in the upper catchment.
8. Using the National Water Act (NWA) to address these impacts to wetlands, in-stream
habitat and shoreline through 1) the definition of a watercourse, natural channel,
wetland, lake or dam, aquatic system and ecological reserve classification, and 2)
prevention and remediation of the effect of pollution to water resources by owners, and
3) licensing subject to impeding the flow and changing the characteristics of a
watercourse.
9. Using the 1) National Environmental Management Act (NEMA), Act 107 of 1998
(NEMA), 2) Draft National Environmental Management: Waste Management Bill of
2006 and 3) NEM: Biodiversity Act.
The Projects
Amongst all the different dam basin and catchment KFA’s, these different wetland related
focus areas includes the optimising of aquatic ecosystem services of wetlands and Instream habitat, both upstream and within the dam basin. This includes phytoremediation,
bioremediation and hyperaccumulation principles implemented in four KFA’s:
1. Floating wetlands;
2. Shoreline rehabilitation;
3. Natural wetlands and Artificial Functional Wetlands (AFW’s); and
4. In-stream Habitat stabilization and re-vegetation.
Nutrient Load Reduction Compliance & Enforcement (Integrated Water Resource Managment) 4 & Riparian Vegetation) In‐stream Habitat (Riverbank 3 Wetlands Protection: Rehabilitation & Artificial Systems Organic Recycling & Treatment (Vermiculture/Earthworms) Floating Wetlands Shoreline & Wetland Rehabilitation Foodweb Restructuring & Fish Manipulation 2 Sediment Management 1 Biomass Harvesting (Algae and Hyacinth) Figure 2: Dam Basin and Catchment showing the Key Focus Areas (KFA)
1) SHORELINE REHABILITATION:
Shoreline vegetation serves vital functions for the protection and maintenance of
diversity of water quality thereby performing beneficial and valuable eco-system
services including:
• filtration and reduction of sediments, nutrients, pathogens and toxins in runoff;
• bank stability; and
• reduction of erosion, to name a few.
Figure 3: Artificially improved/enhanced shoreline conditions for fluctuating water levels
2005
2008
Figure 4: Example of shoreline rehabilitation
Figure 5: Example of proposed extended shoreline wetland area at Ifafi
Figure 6: A proposed aquatic inter-linked system
Shoreline rehabilitation Objectives:
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Develop a rehabilitation plan which includes:
the most desirable indigenous plant communities;
increase foraging and breeding areas for fish;
manipulating the topography of the littoral zones to provide suitable habitats for the
plant communities which will be established.
Stabilize and improve the functionality of the shoreline riparian vegetation zone thereby improving:
water quality; biodiversity; flow regime; storm-water dissipation and erosion control.
Create wetland habitats.
Improving ecosystem services.
Replicate wetland functions - to continuously keep nutrient recycled throughout the
foodweb.
Protect the wetlands, riparian vegetation and in-stream habitat at HBPD
Incorporation of bioremediation, phytoremediation and hyperaccumulation principles.
Developing a shoreline littoral zone EcoClassification system to assist in optimising
rehabilitation options.
Developing Resource Quality Objectives (RQO’s) for inclusion in water use
authorisations for developments around HBPD.
Figure 7: Seriously altered shoreline (peninsula and concrete & Loffelstein bricks).
Shoreline EcoClassification and Resource Quality Objectives:
The development and inclusion of a shoreline littoral zone classification (being the HBPD
shoreline) into the Department of Water Affairs zoning classification - as only the “reserve
determination” classification exists for rivers and In-stream habitat.
This will include the Present Ecological State (PES), Best Attainable Ecological
Management Class (BAEMC) and Desired Future State (DFS) / Recommended Ecological
Category (REC) to be defined.
The project further looks at the best available intervention methods for each management
node of the dam with intervention methods considered, and this will include rehabilitation
mechanisms per unit, floating wetlands, swales, offset areas, littoral zone REC and
shoreline REC.
Based on the outcomes of this research, the information will be used to define the
resource quality objectives for the dam as well as the specific requirements of each
landowner along the shoreline of the dam. These Resource Quality Objectives (RQOs),
namely “Annexure 4” of the water use licences to be issued to each shoreline landowner
around the dam.
Figure 8: EcoClassification : Shoreline and Littoral Zone REC
Shoreline rehabilitation achievements:
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Developed conceptual design for addressing fluctuating dam water level.
Compiled Shoreline strategy and implementation plan for different management
zones.
Compiled Draft Proposal for Ifafi shoreline wetland area.
Stakeholder information, communication and capacity building.
Developed RQO’s classifying the shoreline littoral zone EcoClasses.
Piloted vegetation implementation at selected sites.
Compiled several draft Operational Guidelines for Developments:
- Organic Material incorporation.
- Jetty Construction.
- Golf Course construction.
- Algae & Hyacinth suggested mitigation measures.
Figure 9: Operational Best Practice draft Guideline – Organic material introduction
Figure 10: Operational Best Practice draft Guideline – Jetty construction
Figure 11: Operational Best Practice draft Guideline – Golf course construction
Shoreline rehabilitation challenges and lessons learnt:
• Maintenance and management (algae accumulation, litter and debris).
• Positioning to adapt to varying and fluctuating water/dam level.
• Aesthetic acceptability (general public perceive vegetation as “dirty” areas and
obstacles to recreation activities).
2) FLOATING WETLANDS:
Aimed at replacing the shoreline vegetation which has been destroyed in areas
where the shoreline cannot be re-structured due to development which has taken
place.
Figure 12: Floating Wetland Foodweb
Floating Wetland Objectives:
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Achieve increased zooplankton populations and diversity.
Create a habitat for zooplankton and small fish.
Allow for the establishment of macrophyte biodiversity within the water body.
Establish a habitat which will encourage the development of macroinvertebrate
diversity within the water body thus creating food for fish and birds.
Possible breeding and shelter for fish spawn.
Stabilize water temperature along the shoreline.
Function as energy breakers for water action to reduce turbidity along the shoreline.
Develop technology which will allow the establishment and management of floating
wetlands of indigenous plants within the water body.
Supplement for shoreline/riparian vegetation destroyed in the construction of and
development of housing schemes and golf courses.
Provide a nursery facility for indigenous macrophytes for distributing to new
wetlands being established in the dam and for distribution to other water bodies in
SA with similar problems.
Figure 13: Where floating wetlands needs to be placed
Floating wetland achievements: •
Developed and piloted different prototypes and conceptual Operational Best
Practices.
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Constructed total of (534 x 18m2) 9612m2 of floating wetlands by the end of 2009.
Developed implementation strategy.
Improvement of diversity (zooplankton and macro-invertebrates).
Figure 14: Proto Types and Route Growth
Figure 15: Prototypes and root-growth
Floating wetland challenges and lessons learnt:
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Anchoring.
Long term stability, buoyancy and durability.
Maintenance and management (algae accumulation, litter and debris).
Positioning to adapt to varying and fluctuating water/dam level.
Aesthetic acceptability (general public perceive vegetation as “dirty” areas and
obstacles to recreation activities).
3) WETLANDS UPSTREAM:
Names like marsh, sponge, delta, vlei, iXaposi (Zulu), bogs, swamps and peatland are
also used. Wetlands exist in saturated, flooded and waterlogged areas, either due to a
high groundwater table or inundated by surface water for long enough to be
unfavourable to most plants but favourable to plants adapted to anaerobic (no or very
little oxygen present for use by plants and microbes) soil conditions. Wetlands through
sediments and biomass trap nutrients in the water. This rich nutrients trap (wetland)
imports and exchange more nutrients from the surrounding environment and becomes
a super recycler of nutrients through a high diversity food web. Wetlands provide
numerous immensely beneficial and valuable eco-system services which are unique
and inherent for people and wildlife including:
• Trapping and recycling nutrients and sediments;
• Cleaning, filtrating and purifying the water;
• Storing (like a sponge) and slowing floodwaters;
• Maintaining surface water flow;
• Wildlife habitat and biological productivity.
Figure 16: Natural wetlands adjacent to HBPD
Figure 17: Biodiversity at wetlands
Wetlands Upstream Objectives:
• Protect natural wetlands;
• Remediate impacted wetlands;
• Construct Artificial Functional Wetlands (AFW);
• Increase biodiversity in catchment and reduce nutrient load by recycling nutrients;
• Increase ecosystem services;
• Incorporating phytoremediation, bioremediation and hyperaccumulation principles.
Protection of natural wetlands:
- The identification and preservation of natural wetlands in the catchment and around
HBPD which could play an important role in purifying the highly nutrient loaded
receiving waters in the rivers and streams that feed the HBPD;
- Remediate those wetlands that are degraded (e.g. by erosion) to optimise their
functionality in collaboration with Government Departments, landowners and
Working for Wetlands;
- Replacement of alien invader vegetation and re-vegetate with suitable indigenous
plants;
- Develop Operational Best Practices as part of preservation strategies to mitigate the
negative impacts from irresponsible and unsustainable use for wetlands, watercourses, rivers and the associated riparian vegetation zones.
Artificial wetlands:
- The implementation of artificial functional wetlands (AFW) mostly at point-source
pollution sites as a polishing process.
- There are many different AFW designs including surface flow wetlands, sub-surface
flow wetlands and typical reed-bed systems - each site warrants it`s own design
depending on the intended requirements.
Figure 18: Example of AFW
These actions in turn will reduce the amount of toxic algae and increase biodiversity,
instead of mono cultures, such as the desired foodweb and biomass in HBPD.
Figure 19: Examples of Wetlands Destruction Figure 20: Examples of Wetlands Destruction
4) IN-STEAM HABITAT:
Riparian vegetation and stream banks perform vital functions for the protection of water
quality thereby perform beneficial and valuable eco-system services including:
• filtration and reduction of sediments, nutrients, pathogens and toxins in runoff;
• bank and flood plain stability;
• habitat for natural communities including aquatic and terrestrial species;
• reduction of erosion;
• wildlife food supply and aquatic energy food chain roles;
• flood attenuation;
• infiltration of surface water and biological productivity.
Figure 21: In-stream Habitat
In-stream Habitat Objectives:
• Stabilize and improve the functionality of the In-stream habitat, the riverbanks and
riparian vegetation zone to improve the:
- water quality; flow regime; biodiversity
- erosion control; storm-water reduction & dissipation;
- reduced sedimentation;
- reduced storm-water peak flows;
- recharge of ground water;
- stream bank, channel and floodplain stability;
- aquatic habitat & aquatic biota;
- maintained base-flow & ground water recharge;
- water temperature & light control (shading & lower light levels)and create micro
climate and habitat;
- filtration of nutrients, pathogens & toxins in runoff;
- habitat for wildlife: the life cycles of several species occur or rely on terrestrial
riparian corridors for a portion of their life cycle or for food.
• Developing Storm-water Guidelines, Operational Best Practices (OBPs) & Standard
Procedures to give effect to Higher Order Policies, Plans and Programmes which
mitigate the negative impacts to our water resources, which include wetlands, instream habitat and drainage lines etc.
A number of OBPs are being developed that address a variety of development
activities. The purpose of these OBPs is to influence these activities in such a way
as to reduce their adverse impact on the quality of water entering the Hartbeespoort
Dam. The OBPs will be produced in two formats – a fully descriptive guideline
document and a brief illustrated pamphlet. Both documents will be made available
to the public/potential users on the Metsi a me website.
• Create a vegetation ‘bank’ to facilitate the re-vegetation purposes in the bigger
catchment.
Figure 22: In-stream habitat destruction
Wetlands Upstream and In-stream Habitat achievements:
• Identified 19 wetland and riparian zones around and adjacent to HBPD. Ref (1)
• Compiled several strategy and concept documents for Wetlands and In-stream Habitat,
including the Impact Guiding document. Ref (2)
• Formed Wetland Working Groups at the Skeerpoort, Xanadu and La Camargue
wetlands – to promote awareness and obtain buy-in to preserve the wetland by certain
developers and sandminers.
• Assisted Department of Water Affairs (DWA) Regional office officials as well as
Madibeng Municipality regarding wetlands and in-stream habitat impacts, for them to
take action.
• Compiled wetland posters, factsheets and information booklet. Ref (3)
Wetlands Upstream and In-stream Habitat challenges and lessons learned:
• The lack of knowledge and awareness by the general public of what wetlands, in-stream
habitat and water resources are, and the importance to man, wildlife and the
environment. This includes several developers around HBPD and in the catchment.
• During the development, urbanization and mining, due to other drivers in place
(economic) and lack of alternatives for inappropriate land characteristics, this results in
increased hard surfaces, quicker runoff, less infiltration, more energy and erosion which
accumulates in desert conditions (desertification).
Figure 23: Urbanisation
• This includes dwindling potable water due to severe impacts to ground water infiltration.
• The conflict between environmental protection and economic drivers are perceived to
be opposing instead of the possible synergy to unlock the potential of both.
• The ever-growing lack of knowledge, skills and capacity within the developmental and
management domains.
SOCIAL ECONOMIC BENEFITS:
The aim of the Harties Metsi a Me Integrated Biological Remediation Programme is to
unlock a variety of social economic benefits. Some of these benefits may already accrue
early during the programme, whilst others will become more evident on the medium to long
term. Although some benefits may be linked to specific activities, the biggest result will
only emerge from the collective impact of the programme as a whole.
Social economic benefits - short term to medium term targets:
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Mobilization of stakeholders to:
- Establishing a sense of ownership and co-responsiveness;
- Creating an awareness to initiate behavioral change towards more responsible
actions to live less wasteful;
Stimulate economic growth and job creation by reducing the ill effects of pollution;
Transfer of knowledge, skills and capacity building of the broader public, community
members and officials;
Reduced environmental impact and stimulate growth and development through the
establishment of Waste minimization, Recycling (re-use of organic materials for
Vermiculture (earthworms) and Aquaculture; and
Efficient water use and remediation, anti-desertification and rainwater harvesting.
Figure 24: Job creation and Vermiculture
GLOSSARY
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Point-source pollution : pollution caused by Waste Water treatment works, Mines,
Industries, Intensive Feedlots and Stormwater.
Phytoremediation (phyto = plant) : utilizing plants to remediate;
Hyperaccumulation : the ability of some plants to accumulate larger amounts of
unwanted minerals and nutrients (e.g. phosphates, nitrates and metals).
Bioremediation : natural biological processes.
HBPD : Hartbeespoort Dam.
REFERENCES
1. Wetlands Upstream and Instream Habitat Site Map www.dwa.gov.za/harties/
2. Wetlands Upstream and Instream Habitat Strategies www.dwa.gov.za/harties/
3. Wetlands for Life Hartbeespoort Dam Wetlands and Riparian Zones Poster
www.dwa.gov.za/harties/
4. Wetlands for Life Wetland Projects Poster www.dwa.gov.za/harties/
5. Floating Wetlands & Shoreline Vegetation Fact Sheet www.dwa.gov.za/harties/
6. Wetlands for Life Fact Sheet www.dwa.gov.za/harties/