By Chris Ezeh – Publisher EuroAfricaNews Magazine Online
and Director – EuroAfrica Media Network
In many Nigerian communities (especially in Imo, Abia, Enugu and Anambra States) people are building structures indiscriminately, destroying forest vegetation or plants and plastering available green areas with impermeable cement without realising the disastrous environmental consequences this act might cause.
First Things First: Identify Real Causes, Act on Simple, Cheap Solutions!
How do you tackle erosion problems in our communities? I am shocked always when I hear well-educated people talking about solving erosion issues. Their solutions are often very short-sighted and lack competence. One cannot solve erosion menace by simply building more roads, grading roads putting up culverts and gutters. To solve a problem once and for all, you must start at the cause and not at the symptoms. Floods and erosion disasters are symptoms of poor, uninformed, human environmental activities on land. Therefore you must ask: Where are the main causes of the problem? That is where to start!
The Problem and Effects of Soil Erosion
The “greatest irony of the entire story” is: Many State Governments in East and Southern Nigeria in a frantic, unprofessional effort to check soil erosion and landslides, have been spending millions of Naira over the past 10 years building roads, pavements, drainages without attending to the crux of the matter:
Here are the causes of erosion which need to be addressed first.
1) For each house, preventing Rain-water from roofs getting into roads, by adding rain-harvesters in buildings
2) Reducing the speed of rainwater flow and chanelling this into the soil in each compound for absorption
3) People´s attitudes towards raising structures eg why have a highroof in rainforest zone?and
4) Environmental/ecological awareness Training.
The main culprit is that the roofs of such buildings/structures are not provided with rain-collectors so within minutes of little rainfall, the entire rain water from all houses converges and pours through streets and trails (which are unpaved). At the very least this results in ruts and minor floods, at worst this rainwater runoff from major storms often in seconds, turn into a large floods which many times have claimed thousands of lives or destroyed properties.
Water drops from the Roofs of the Buildings Remain the Main Cause of Erosion and Floods in our Communities:
Many people born in the 1950´s and 1960´s still remember lots of the remnants of the village forests patches designated to special deities and so highly respected, that no one in those days, dared to tamper with such vegetation. In those days we had no erosion issues. You might also remember the thatched houses of our old-childhood days called in Igbo, “Ulo Akirika” (thanks to its great water absorbing qualities, it took at least more than 30 minutes before raindrops could fall on the ground from such roofs) and the water tanks of the old known as “omi” in Igbo helped keep water both for storage and also away from the local roads. All these helped keep erosion at bay.
UNDERSTANDING THE ROOT OF EROSION IN OUR VILLAGES
But the fact is: Before you built a house or any other structure on a piece of a virgin land, there were no erosion issues …right? This is because the plants and vegetation on that piece of virgin-land not ONLY helped to cover the soil, but they also helped slowly channel the raindrops into the soil. Now if you build a house, your new building replaces this “natural green absorbers of rain”. You must therefore ensure that the natural water-absorbers you have displaced as a result of your building is re-channelled into the same soil through storm water runoff system to avoid erosion. If you don´t and all neighbours do same mistake, you should then not be surprised when gully erosion visits your village! See images above
Each individual who builds a house or any structure in our town or village must have the responsibility to control and check water erosion generated by his or her structure. You do not have to wait for 1 Million Naira fund, local ordinances or GOD to come from HEAVEN before you can undertake action. There are very simple steps you can take to save your community from erosion menace. Start your own storm water runoff mitigation efforts with simple fixes that don’t cost a penny.
TO STOP EROSION AND FLOODS
All adults, students, and, indeed, the dwellers of the entire village must be educated on the importance of erosion control using proper methods for building houses and other structures.
What is storm or rain-water runoff? It’s any natural precipitation that doesn’t soak into the ground where it falls. When rain hits the hard, impervious surfaces associated with modern life – driveways, sidewalks, streets, rooftops, parking lots –it’s channelled toward storm water drainage systems. In many communities, these drainage systems empty into natural waterways.
Rainwater Harvesting Systems and other Erosion Control Systems:
Rainwater harvesting systems can provide potable and non-potable water requirements for villages throughout the year. These systems can provide water for cooking, toilet flushes, car washes, garden and farm irrigation and so on. Villagers will be thought to be multiplicators themselves, to get what they learned across to others, They will learn how to install a locally-made catch tanks either under or above ground, to harvest the unwanted rain water from the roof, driveway or any other hard standing or paved area which otherwise would land on the streets as flood.
Advantages of Rain-Harvesting-System to the Communities:
1) More water means Less boreholes – thus less damage to ground-water
2) More free water for household use means less cost for water bills etc.
3) Less cost for materials and accessories e.g. water pumps etc.
4) Most importantly, less water runoffs and on the streets, thus less erosion
5) Great for the environment and balanced ecology (flora and fauna).
How can storm-water runoff be a problem?
- Large volumes can overwhelm storm drains and cause localized flooding.
- Large water volumes can cause erosion and destroy structures.
- Runoff gathers sediment and pollutants, which can wind up in natural waterways.
- Water that doesn’t soak into soil can’t recharge local groundwater sources and even cause serious pollution problems including health epidemics
The goal of managing rain-water runoff includes:
- Decreasing the volume
- Reduce water runoff speed
- Minimizing the pollution and erosion.
10 STEPS TO STOP EROSION AND FLOODS IN OUR COMMUNITIES
The Three Main S-MOTTO for storm water runoff management is: Slow it down, Spread it out, and Soak it in. Consider these affordable, do-able solutions to do just that.
- Add plants: Incorporate plantings, especially in areas where runoff collects. As runoff soaks into soil, plant roots help to absorb and filter out pollutants. When runoff soaks into and percolates through soil, the soil also acts as a filter, removing some pollutants.
- Protect trees: Like other plant roots, tree roots help absorb and filter runoff. Tree canopies also slow rainfall and spread it over a larger area.
- Break up slabs: Replace concrete patio slabs with pavers, flagstones, or bricks that allow water to soak in between items. For driveways, consider using turf block or leaving a strip of grass up the centre.
- Go permeable: Choose a permeable material for a path, patio, or driveway. Less expensive options include aggregate base, gravel, mulch, or crushed shells. Pricier options include pervious concrete or asphalt.
- Catch runoff: Install a rain barrel or cistern to catch storm water runoff from roofs. Use this water to irrigate garden plants, shower or flushing toilets.
- Dig a trench: Use a shallow, gravel-filled trench to catch and slow runoff, especially at the base of a slope or alongside a driveway or patio. For slopes, consider creating a dry creek to catch, slow down and direct runoff, perhaps to a rain garden (see below).
- Plant a rain garden: A rain garden is designed to catch and slow runoff. It’s frequently planted in low areas, at the base of a slope, or near downspout outlets. The design includes soil layers, mulch, and plants, all of which filter rainwater as it seeps into soil. Check with your local Government Agro-Forestry Department to learn rain garden basics.
- Cover soil: Depending on the type, bare soil can be like concrete in terms of its ability to absorb water. Cover bare soil with mulch or quarry stones to slow storm water runoff.
- Swap lawn: Trade turf for native plants, which are adapted to local growing conditions and require fewer inputs (once established) than turf.
- Drive on the grass: If your driveway isn’t permeable, wash your car on the lawn so water can soak into soil, instead of running into the street.
No matter what method you choose, always direct runoff away from your home’s foundation. If your property has a steep slope or receives additional runoff from an external source, consult with a professional landscaper to discuss possible solutions.
Inform your neighbours too so the news will spread. In this way the communities will be learning from one another and it will be knowledge merry go round