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sediment could still filter through and accumulate and settle behind the
dams. In Java the approach is similar: villagers hammer bamboo poles at
least two meters into the seabed and use bundles of brushwood from the
shore, binding them together to form dams of about 100 meters long. In just
one year, the level of the bed can rise by up to 50 centimeters. However, it
is not enough that we provide a technical solution in Demak; there are many
ecological and socio-economic issues to be addressed through the program.
Here we see the benefit of the multidisciplinary character of the Building
with Nature program. Our EcoShape team consists of companies with a lot
of engineering expertise like Boskalis and Witteveen+Bos, but also includes
research institutes like Deltares and Imares, NGOs like Wetlands
International and Blue Forests as well as local and national government
agencies.”
Local community engagement
Femke: “The local community had to be convinced that a wide natural
mangrove belt is needed both for their own safety and for keeping their
land. In addition we had to show that they can still farm shrimp behind the
restored mangrove greenbelt: this is their livelihood. So a lot of education
and training is needed. We have set up Coastal Field Schools to train
villagers so that they can identify and develop successful aquaculture
practices and care for the mangroves they depend on for coastal safety and
water purification. We also developed Bio-rights, an innovative financing
mechanism for reconciling environmental conservation with sustainable
development. For example, we provide financial support and training so
that farmers can revitalize their shrimp ponds, start a crab farm or develop
ecotourism. In return for this support, villagers help to maintain the permeable
dams, they monitor mangrove recovery and safeguard the mangroves once
restored. In some cases farmers need to give up ponds near the seafront or
along rivers to facilitate mangrove restoration. This then needs to be
compensated, for example by achieving higher aquaculture productivity
in ponds behind the intended greenbelt.”
Restoring ecosystem services worldwide
Fokko: “Looking at the equator, we could take a similar approach in
countries with comparable vulnerable coastlines such as Vietnam, the
Philippines, Malaysia, Bangladesh, India, as well as countries in Africa and
Central America. Suriname, for instance, is one of the seven globally most
endangered countries in terms of sea level rise. In May 2016 a Building
with Nature project in Suriname was launched to protect the coastline from
seawater flooding and prevent salinization of arable land. The approach
replicates the Building with Nature program in Central Java to bring a halt
to coastal erosion.”
Femke: “This represents a new way of looking at coastal safety and coastal
defense systems. It is a low-tech solution but requires high-tech knowledge
and expertise. In many locations it is not ecologically and economically
feasible to implement hard infrastructure solutions, such as dams or dikes.
Instead, this approach is cost-effective and brings multiple benefits to various
stakeholders by restoring ecosystem services. We believe it can transform
the way in which erosion problems are addressed along muddy coasts
across the tropics.”
“We believe it can transform the
way in which erosion problems
are addressed along muddy
coasts across the tropics.”
Construction of the permeable
dams by local villagers.