FASCINE

Work related project | Individual project

Case study | Regenerative Design

”What if we could design an efficient way to restore rivers in symbiosis with nature?”

This was a case study that I worked on at INDEED Innovation. The study focuses on SDG #14: Life below water.

I looked into the dangers and potential remedies for endangered river banks within this project. It highlights my findings and a possible Regenerative Design solution for a sustainable restoration that is made for for any community to utilize.

 

Background

River biodiversity loss is enormous and is in urgent need of restoration. Freshwaters, like rivers and streams, cover less than 1% of all the water on the earth but still provide a habitat for 40% of all the world’s species. This wildlife needs to be protected. Since the 1970s, the global freshwater species have declined by 84%, primarily due to human interference, such as encasing rivers in concrete. The ecosystem is under pressure, leading to streams becoming unhealthy.

Healthy streams are not straight, they have an organic structure and flow as it has grown naturally over decades. This leads the water to run free at a good pace. A high flow rate will lead to soil loss, erosion, and habitat degradation. Rivers need texture, nooks, and crannies for wildlife to thrive and to create a balance. An equal amount of sediment should be coming in as well as going out. It is important that the water does not run too slowly nor too fast in order to form a healthy river to improve biodiversity.

One traditional way to solve the problem is the faggoting technique. This is used in rivers and streams to stabilize the bank side erosion and to narrow a stream when it has been over-widened over the years. The faggoting technique uses faggot bundles or fascines, these are usually made out of wood sticks bundled together with a strong rope.

The bundles uses wooden sticks since they must be made in a natural and biodegradable material that offers nooks and crannies for freshwater wildlife to hide and thrive. As the bundles biodegrade, they will become part of the riverbank over time, narrowing the stream as it feeds the food chain.

These fascines also holds plants or seeds that will sprout, stabilizing the riverbank over the years. Plants that has a long root systems and thrives in water are the best option for better stabilization. The vegetation roots will over time act like a rebar, binding soil to resist erosion. The growing vegetation also provides oxygen to the water as well as cooling down the streams and rivers, enhancing freshwater biodiversity.

Problem areas

The traditional practice of fascines is unfortunately flawed. The fascines are built by hand and placed manually. Today it seems inefficient and very time-consuming. In recent years, NGOs and volunteers have kept up with the initiated projects.

The amount of wood/forestry is immense to save relatively small areas. Therefore, the practice is inappropriate for areas where wood is a limited resource,

For these bundles to work properly, all wood used has to be free of splits, rot, disease, and insect infestation. This is something that is very hard to control when using the traditional faggoting technique.

Lastly, the ropes used are seldom biodegradable. Usually, synthetic ropes are used since they are more robust and last longer. However this leads to another issue, being that the ropes break down over time, creating microplastics that end up in the rivers and later in the oceans, ruining biodiversity in other places, making this issue more severe.

concept idea

To solve the problem, I thought about molding a biodegradable (nature-friendly) structure based on mycelium. If the river or stream is shallow, roughly 1x1m can be adapted with smaller molds. Mycelium is very strong and lightweight - like wood - yet available at scale. It can be molded in a vacuum-formed rPET mold-frame for efficient, cheap and more sustainable production. Multiple structures can be developed at the same time and not all has to be done by hand. Mycelium is extremely resource friendly and for this solution no wood has to be chopped down, nor any synthetic rope that releases microplastics has to be used. It is also easier to control that the material is completely free from splits, rot, disease, and insect infestation.

The starter kit consisting of 2 parts:

Mycelium Starter | Mycelium (given a fungus culture) + local bio-waste (e.g. hemp, wood chips, psyllium husks, straw). Different bio-waste makes different density of the finished structures, eg woodchips makes Styrofoam-like density and straw makes wood-like density, straw is also more common to be found and is less resource-heavy. straw also results in a less water resistant material which in this case is desirable, since it should biodegrade in the water over time.

 

Plastic Mold | Vacuum-formed frame as a mold, due to it being an easy, simple, efficient, and cheap method to make the final mycelium structure. The preferred material would be rPET plastic, since it is affordable, strong, long-lasting, versatile, more sustainable as it can be recycled many times at the end of life (EOL).

 

Together these two parts creates a third part, being the final product:

Mycelium Structure | Molded structure to bring back biodiversity in rivers and streams and to stop erosion

 
 

The Mycelium starter has to be very precise, so this might part might not always be done on site. However it may easily be shipped anywhere in a small envelope. As for the other steps, they may all be done on site.

You can use any agricultural or bio-waste bound. If available, it is preferable to use straw since it is less resource-heavy. Straw also allow for a more wood-like and less water resistant structure, which is preferred since it should biodegrade in the water over time.

The growth period is 2-7 days, depending on temperature and moisture ratio. An oven is sufficient to burn the structure after the growth is done to stop it from growing further. It does not require any extreme heating, since it only needs 95°C/200°F to stabilize the structure.

After stabilization, local soil and seeds and/or water plants. They are then placed side by side to create a wall at the river/stream bank. After that nature will over time do its job andtake over enhancing the freshwater biodiversity.

The solution will suit any place that has erosion problems or lack of biodiversity in the streams and rivers.

  • In the city where concrete covers the riverbanks

  • Rural areas where over-widened rivers provoke weak riverbanks.

  • Places where deforestation is an issue.

In the long run, it is a more sustainable process than, for example, using wooden bundles. It takes about 50 years to grow a tree, and the mycelium only takes 2-7 days and can be redone repeatedly, not using nature faster than it can regrow or regenerate.