Management of Africa’s Wetlands, page 1

Developing Further the Draft Action Plan for

Managing Africa’s Wetlands under the Framework

of the Environment Component of Nepad

(Valencia, Spain, 17 November 2002)

Background Document

New Partnership for

Africa’s Development - NEPAD

Thematic Paper

on

Management of Africa’s Wetlands

DRAFT FOR DISCUSSION

6 November 02

Table of Contents

Page

  1. Introduction3
  1. Economic and Social Values of Africa’s Wetlands4

A. Flood Control5

B. Groundwater Replenishment 5

C. Shoreline Stabilization and Storm Protection 6

D. Sediment and Nutrient Retention and Export6

E. Climate Change Mitigation7

F. Water Purification8

G. Reservoirs of Biodiversity9

H. Wetland Products9

I. Recreation and Tourism10

J. Cultural Value10

III. Threats to Wetlands11

IV.Overview of Activities to Manage Africa’s Wetlands 12

  1. Introduction
  1. Human civilisations have over 6000 years flourished in river valleys, their floodplains and other wetland systems reflecting the key role that wetlands play in supporting human life. The complex interaction of the basic components of wetlands - soil, water, animals and plants - fulfil many functions and provide the many products that are what has sustained humans over the centuries. A recent ecosystem study valued the services of different wetland types, as follows[1]:

Total value Total global flow

(US$) value (US$ per year)

per hectare per year

Estuaries 22,382 4,100,000,000,000

Seagrass/algae beds19,004 3,801,000,000,000

Coral reefs 6,075 375,000,000,000

Tidal marsh/mangroves 9,990 1,648,000,000,000

Swamps/floodplains 19,580 3,231,000,000,000

Lakes/rivers 8,498 1,700,000,000,000

2.However, while the economic values of these wetland types are high, human induced threats continue to adversely impact wetlands which, in turn, plagues the ability of the continent to recover from its development and economic crises. Global freshwater consumption for example has risen sixfold between 1900 and 1995, a rate more than double the rate of population growth. This is compounded by the fact that a third of the world’s population today lives in countries already experiencing moderate to high water stress.

3.Wetlands are hugely diverse and exist in the form of floodplains ponds, marshes, coral reefs, peatlands, lakes, mangroves, seagrass beds or swamps and they can also be manmade. For the purpose of this document, the Ramsar Convention[2] defining what wetlands are is used although noting that other definitions of wetlands do exist. The Convention defines wetlands as:

“areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres”.

4.Therefore, in line with this definition and for the purpose of this Action Plan, the term “Wetlands” is used to encompass the following hydrological Systems:

  • Marine and Coastal Wetlands, including permanent shallow water in most cases less than six meters deep at low tide, marine subtidal aquatic beds, coral reefs, rocky marine shores, sand shores, estuarine waters, itertidal marshes, mud, sand and salt flats, intertidal forest wetlands, coastal lagoons, karst and other subterranean hydrological systems.
  • Inland Wetlands, including permanent inland deltas, permanent rivers/streams /creeks,waterfalls,seasonal/intermittent/irregular rivers/streams/creeks, permanent freshwater lakes, seasonal /intermittent freshwater lakes, permanent saline/brackish/alkaline lakes, permanent or seasonal marshes, forested and non forested peatlands, freshwater tree- dominated wetlands, shrub-dominated wetlands, freshwater springs, oases, geothermal wetlands, karst and other subterranean hydrological systems.
  • Human-made wetlands, including aquaculture (fish/shrimp) ponds, farm ponds, stock ponds, irrigated land, seasonally flooded agriculture (including intensively managed or grazed wet meadow or pasture), salt exploitation sites, water storage areas, excavations, waste water treatment areas, canals and drainage channels and ditches, karst and other subterranean hydrological systems

5.The goal of this Action Plan to Conserve Africa’s Wetlands, as one component of the Framework Action Plan for the Environmental Initiative of NEPAD, is to sustain and restore Africa’s wetlands, their functions and the resources they provide. The document presented here further develops the programme area described in the Framework Action Plan for the Environmental Initiative of the New Partnership for Africa’s Development (NEPAD) on conserving Africa’s wetlands.

6.Recognizing that a specific thematic building block of the NEPAD Action Plan is covered under the “Marine and Coastal” Component, it is the intention of this part of work to highlight the important linkages between the freshwater issues in the upstream river basins and the water issues in their adjoining coastal zones. For instance, changes in river flows and water quality caused by human activities on river basins have changed the water quality on estuaries, lagoons, and mangrove forests.

7.The document broadly discusses the social and economic values that wetlands provide given the implications that Africa’s wetlands have on the continent’s economic recovery and its ability to meet its development goals. It discusses the threats that Africa’s wetlands are faced with that hinder their ability to provide the services and products that the continent’s development and economic recovery rests upon. In the final sections, it provides an overview of the strategies and the wetland management actions that have been undertaken in Africa and provides a way forward on new strategies and possible areas of intervention that would constitute the Action Plan to Conserve Africa’s Wetlands. The document draws heavily from the work of several bodies including the Ramsar Convention Secretariat, the CBD Secretariat, Wetlands International, the US EPA, IUCN, WWF and others in the field of wetland management. The interventions presented are not a blueprint but rather a starting point for discussion by the Thematic Working Group on Conserving Africa’s wetlands.

II.Economic and Social Values of Africa’s Wetlands[3]

A. FLOOD CONTROL

8.Africa’s wetlands bear an important economic function in that they hold rainwater and runoff, preventing possible flooding downstream. By storing the water in the soil or retaining it in their surface waters, they reduce the need for expensive engineered structures. The “value” of this function is not often assessed in economic terms, although certain studies cited by the Ramsar Convention secretariat show that where efforts are made the value proves to be considerable.

9.The intact 3,800 hectares of wetlands along part of the main stream of the Charles River in the USA have been valued at US$ 17 million per year, the estimated cost of flood damage that would result if they were drained. The Chinese have suffered an increasing frequency of devastating floods since the turn of the last century, their worst floods occurring in 1998, affecting several rivers including the Yangtze where 230 million people were affected, 20 million people displaced, over 3,500 killed, 7 million homes destroyed, 15 million farmers suffering loss of their crops and an estimated total economic loss exceeding US$ 32 billion. The Mississippi River was also subject to numerous engineering projects to control floods and improve navigation through the construction of thousands of levees, the creation of deep navigation channels, and the destruction of 6.9 million hectares of wetlands. The 1993 floods in the Mississippi were estimated to result in US$ 12-16 billion in damages.

10.Analysis of the causes of flood damage often point to settlements being established in low-lying areas subject to floods, reclamation of the wetlands around lakes and rivers for cultivation to feed the growing population, thus reducing their flood absorption capacity and deforestation in the upper reaches of watersheds.

B. GROUNDWATER REPLENISHMENT

11.Underground aquifers store 97% of the world’s unfrozen freshwater and they provide drinking water to almost a third of the world’s people. The relationship between groundwater and wetlands differs from case to case with some wetlands owing their existence to groundwater that has come to the surface while in others they overly the aquifer allowing water to recharge the aquifer directly. The Zeroud, Merguellil and Nebaana rivers in Tunisia for example recharge the aquifer during floods and when rivers run dry, the water in the aquifer supplies irrigation needs all the year round. The desert coastal towns of Walvis Bay and Swacopmund in Namibia are entirely dependent on groundwater from aquifers recharged by ephemeral rivers.

12.Direct removal of water from aquifers for agriculture is common all over the world and thus in monetary terms the value of the recharge function of wetlands cannot be underestimated. The value of Hadejia-Nguru wetlands in northern Nigeria in recharging aquifers used by local people for domestic water supplies has been estimated at US$ 4.8 million per year.

13.In a number of countries the direct removal of water from aquifers for crop irrigation has increased dramatically in recent decades. Currently 17% of the world’s cropland is irrigated and it is estimated to provide around 40% of the world’s food. Irrigation has brought great benefits to many countries – but it is also raising serious concerns as the rate of extraction often exceeds the rate of replenishment.

14.On a local scale, the recharge function of the Garet El Haouria wetland in Tunisia depended upon winter flooding. Drainage canals to control the flooding removed this function and water abstraction from wells in the area for irrigation of citrus orchards and market gardens dramatically altered the hydrology of the area. Groundwater levels fell by 9m between 1980 and 1995 and some wells have been abandoned because of saltwater intrusion. Such deficits raise concerns over food security and emphasize the value of wetlands in groundwater recharge.

C. SHORELINE STABILISATION AND STORM PROTECTION

15.Saltmarshes, mangroves and other forested estuarine wetlands act as the frontline defence against incoming storms. They help minimize the impact of storms by reducing wind action, wave action and currents, while the roots of the plants help to hold the sediment in place. Hurricanes, cyclones, storm surges and other coastal weather disturbances can cause immense damage through flooding and direct destruction of property, not to mention the loss of human life.

16.In Bangladesh 40,000 people were drowned in 1985 during one storm surge. Mangroves in the Sundarbans break up storm waves that exceed 4 metres in height, and this has encouraged the Government of Bangladesh to invest considerable sums of money in re-planting mangroves in the area to assist in storm protection. The value of intact mangrove swamps in Malaysia for storm protection and flood control alone has been estimated at US$ 300,000 per kilometre – the cost of replacing them with rock seawalls.

17.Shoreline stabilisation is equally important in inland rivers. In the United Kingdom, the loss of vegetation along riverbanks in eastern England was costed at US$ 425 per metre of bank – the cost of maintaining artificial bank reinforcement to prevent erosion. Coral reefs also deliver storm protection. A recent estimate of the value of coral reefs found that the cost of destroying just 1 kilometre of reef ranged from US$ 137,000 to almost US$ 1.2 million over a 25-year period, based on the economic value of storm protection, fishing and tourism.

18.A recent survey indicates that 58% of the remaining coral reefs worldwide are at risk from human activities, with overfishing and destructive fishing practices, as well as coastal development and bleaching associated with climate change, identified as the major culprits.

D. SEDIMENT AND NUTRIENT RETENTION AND EXPORT

19.Wetlands tend to slow down the flow of water, encouraging the deposition of sediments carried in the water. This is beneficial further downstream where deposition of sediments may block waterways. Nutrients are often associated with sediments and can be deposited at the same time. These nutrients, mainly nitrogen and phosphorous from agricultural sources but also from human wastes and industrial discharges, may accumulate in the sub-soil, be transformed by chemical and biological processes or be taken up by wetland vegetation and effectively removed from the system.

20.This capacity for nutrient retention makes many wetland ecosystems among the most productive recorded, rivaling intensive agricultural systems. Annual primary production of Papyrus in some African wetlands is estimated at 100 tonnes per hectare, Typha (bullrush) at 30-70 tonnes per hectare. These figures are similar to or even exceed the commercial production of crops such as maize (63 tonnes per hectare) and sugar cane (60 tonnes per hectare) and the latter require inputs such as fertilizers and pesticides as well as irrigation.

21.Seasonal flooding is a natural phenomenon in most of the world’s rivers. Inland floodplains and coastal deltas are the natural “overflow” areas that slow the velocity of the floodwaters, allowing the nutrients and sediments to settle. These rich floodplains and deltas have sustained populations for thousands of years but continue to do so only in a limited number of cases: for the most part, inland floodplains have been “reclaimed” for other uses (such as agriculture, housing, industry) and engineered flood control structures and dams have channeled the water, destroying the natural movement of sediments and nutrients.

22. Ancient Egypt could not have existed without the great Nile River. Every year, streams flow from the mountains of East Africa, sending a torrent of water that overflows the banks of the Nile. The river picks up bits of soil and plant life called silt. The silt is dropped on the banks of the Nile as the flood recedes, and creates excellent topsoil that provides two or three crops every year. The ancient Greeks spoke with envy when they referred to Egypt as “the Gift of the Nile”. Today, more than sixty million people live along the banks of the Nile, the world’s longest river.

23.The rich Hadejia-Jama’are floodplain in northern Nigeria has been valued at US$ 167 per hectare, in contrast to the US$ 29 per hectare in benefits for the diversion option – a clear vote for maintaining the natural wetland ecosystem. Valued in another way, the water in the floodplain was worth US$ 45 per 1,000 cubic metres in contrast to US$ 0.04 for the diverted water. Failure to correctly value a floodplain can have serious consequences.

24.The Waza-Logone floodplain in Cameroon once supported 10,000 people who practiced fishing and pastoralism. The construction of a dam and flood embankments for a rice irrigation scheme in 1979 exacerbated an already degraded system and deprived the floodplain of the seasonal flooding that brought the essential nutrients to sustain the fishing and grazing. The decision to rehabilitate the floodplain has cost more than US$ 5 million over an 8-year period.

25.Interference with the natural movement of sediment and nutrients can have serious consequences in coastal deltas as well. In the Nile delta, human-engineered structures (flood control structures and dams) have interrupted the normal flow of nutrients and sediments to these deltas that were once rich, productive wetlands of critical importance to local communities for fish and agriculture. The loss of sediment flow has brought about degradation and retreat of the deltas – for example, the Nile delta retreated 2km in a 17-year period following the building of the Aswan Dam – as well as serious problems with coastal erosion as sea water inundates coastal wetlands. In the Nile, the loss of freshwater flows as well as the over-pumping of groundwater have led to saltwater intrusion into the aquifers underlying the delta and stretching 30km inland, contaminating sources of drinking water.

E. CLIMATE CHANGE MITIGATION

26.Wetlands play at least two critical but contrasting roles in mitigating the effects of climate change: one in the management of greenhouse gases (especially carbon dioxide) and the other in physically buffering climate change impacts. Some wetlands such as peatlands and forested wetlands act as significant carbon sinks and so the destruction of wetlands will release carbon dioxide, a greenhouse gas while others emit methane, another greenhouse gas.

27.Wetlands will play a further role as the frontline defenders of coastal and inland areas as countries deal with the full effects of climate change: increasing frequency of storms, changing rainfall patterns, rising sea-levels and sea surface temperatures. The many environmental changes associated with climate change have serious implications for wetlands – key impacts on wetlands include the effects of sea level rise, rising temperatures, and changes in precipitation patterns, ocean currents and winds.

28.Beaches, dunes, estuaries, mangroves and other coastal wetlands are naturally equipped to adapt to changes in prevailing winds and seas and to sea-level rises. The predicted changes as a result of climate change will, however, be increasingly rapid compared to the natural rate of change to which the systems are adapted. Coastal managers will have to assist wetlands to adapt to these changes – dune restoration and rehabilitation and re-creation of coastal wetlands will be essential in some countries.