Flood Reconnaissance - The Southern Banks of the River Nzoia and Current Mitigation Efforts

On Monday, Austin and I finished up our tour of the dykes North of the River Nzoia by biking along a small, final section of the dyke north of the river. Tuesday, we crossed the river to tour the entire length of the dykes intended to protect the villagers south of the river from flooding.

These areas in southern Bunyala District had received the brunt of the battering during last December’s floods, which displaced nearly 25,000 people.

This was a picture taken on Monday from a road along a hill north of the river of the main point of crossing known as ‘Khu Ferry’. The River Nzoia is the main body of water, at the front. Behind it are temporary bodies of water present due to the rising water level.

The river crossing is made by a small canoe-type boat, filled with passengers, bicycles, and motorcycles.

Note how close some families actually reside to the river, unprotected by the dykes. The clothes you can see are hung within one such family’s household.

Flooding is quickly becoming, as it does every year, a matter of urgency. On August 30th, the early warning system was triggered; meaning that the water level had risen to such an extent that flooding along the river could be imminent. And just that same week, the Kenyan Meteorological Department forecasted above-average rainfall in much of Western Province, including the entire catchment area of the River Nzoia, through December. Even now, sustained rains have lingered upstream.

Monday, the local government had planned a Disaster Management meeting, which we, as an organization, were invited to. But after Austin and I waited around the district headquarters for over two hours, it was finally postponed until Wednesday. Time management is unfortunately as much an issue here as it was in Mali.

Despite the frustration of delays, the meeting really helped me to get a proper idea of all of the preparations the local government has made in order to ready the dykes for impending floods. Representatives from all local government ministries and authorities were present. A woman named Madame Lucy, who is the Ministry of Water’s engineer in charge of dyke management, especially impressed me.

The floods from last year had severely ravaged the dykes, with many sections south of the river in a state of total collapse. The ministry’s approach has been the following work, which is performed throughout the year following any flood event and is currently ongoing:

1. Seal and rebuild breached embankments. 
2. Raise the level of dykes that had been overtopped by water. 
3. Address underground seepage locations that undermine the stability of the dykes. 
4. Plant grasses along the banks of the dykes (work performed by community members). 
5. Clear overgrown trees and bushes (again, work performed by community members). 
6. Construct ‘river trainings,’ which are deep excavations made in/beside the riverbed in order to ‘train’ the river to take a new course. These are constructed in order to correct the natural migration of the river and better evacuate floodwaters. 

In addition to these measures, due to the current raised threat level from increased rains, the ministry has also taken additional measures, such as making 10,000 sand bags available, opening additional natural water channels through the dykes to alleviate water pressure and evacuate flood water, and making preparations for emergency relief to flood victims in the case of a flood.

Following the meeting, Austin and I were able to accompany Madame Lucy and a couple other people from the meeting in touring the entire length of the dykes, this time by vehicle. It was a very informative and interesting experience, with Madame pointing out the work that they had been doing in the field. We also discussed potential solutions to some yet-unresolved problems.

Below is our tour of the dykes, in pictures:

The Southern Dykes - Tuesday

Compare this picture to the one from my previous post on the Northern dykes. These pictures were taken from the bridge crossing the river from Ruambwa into Nyanza Province. Note the location of the two banana trees to the left of the woman. The water level has risen here, at the upstream end of the river, dramatically. The difference is even more dramatic downstream.

After crossing the bridge over the River Nzoia, we passed briefly through Nyanza Province before heading west back into Bunyala District. The dykes first begin within Nyanza Province, Siaya District in the village of Bukhoba, but the dyke shortly enters Bunyala District. This picture was taken just after the start of these dykes, in Bukhoba village.

The dyke had broken in these areas last December, flooding the surrounding villages and relocating its residents. Here, the residents had planted grasses along the banks of the dyke in an effort to stabilize it for the future. This was a condition imposed by the government as a form of community contribution, following the work the government did this year to reconstruct the dykes after they were completely washed away.

Here, Austin is speaking with a local woman regarding last year’s floods.

Still in Bukhoba village, men were working to unload sand bags to be placed along the top of the dykes for reinforcement.

The Ministry has been excavating soil nearby in order to rebuild the dykes following the floods from December. Note that the excavator on the right had actually sunk into the mud and had been temporarily abandoned. Madame later explained to us that borrow areas for soil have been hard to come by, so they have actually begun a new initiative. If you want a fishpond, the Ministry will dig it for you. You get a fishpond; the Ministry gets the needed soil.

In Buyuku village back in Bunyala District, Bunyala Central location, Magombe East sub-location, half of the width of a portion of the dyke had been washed out during the flooding in December.

Still in Buyuku village, local boys fish within flooded farmland along the banks of the dyke. The dyke in this location had also collapsed in the December floods, but had since been rebuilt.

Busagwa village, still in Magombe East sub-location, is home to a large rice irrigation scheme, constructed by the government. Although this area in particular wasn’t affected by flooding previously, the threat is there. Workers are planting grass in an attempt to ensure the dykes can withstand flooding to protect the government’s investment.

We then passed through the villages of Magombe Muhondo and Magombe Hulusenye. Villagers in both of these areas were working hard to plant grasses along the banks of the dyke, and I was heartened to see the level of community involvement.

The flooding this past December was especially bad in these communities, where the dyke completely collapsed and was washed away in many areas. Austin had told me that on a late Sunday evening, while he was walking along the dykes along the Northern banks, he suddenly heard the screams of desperation and calls for help from people across the river.

Another picture from Magombe Hulusenye, as women plant grasses along the side of the dyke. 

Homes in this area, such as those shown here, were completely flooded this past December. 

This picture illustrates a potential mode of failure. Water undermines the lower reaches of the dyke, leading to the total collapse of the soil above. This area, Barangasi village now in Magombe West sub-location, did not actually see flooding in the previous year, but did in 2008. Austin, above, is discussing the effects of local flooding with a local elderly woman.

Makunda village is a large village with many residents positioned very near the dykes. Floods devastated the entire area both in 2008 and, more recently, during the floods experienced this past December. The larger buildings with the blue roofs are Makunda Primary and Secondary schools. The students were displaced following the floods, forced to relocate to other area schools.

This picture was taken along the current dyke protecting Makunda. The two mounds on either side of the pool of water are remnants from the previous dyke, which had fully collapsed during previous flooding.

Siuna, within Khajula location, Lugare sub-location, is a relatively highly populated village that was displaced by the floods in December. Homesteads are clustered together, in close proximity to the dyke.

Another picture of local homes within Siuna situated precariously close to the dyke.

Despite the dangers of the river, the local population depends upon its resources for their livelihood. Pictured above is one of the local methods for catching fish. The river also provides the villagers, primarily subsistence farmers, with fertile farmland. Much of this farmland is actually found between the river and the dykes, and is not able to be farmed after the month of April, when they are often completely flooded.

After completing our tour of the dyke, we backtracked until we returned to a location known as Khuferry. Here, we biked across a land bridge spanning the flooded areas between the dyke and the river. Previous flooding has eroded much of the bridge, consisting of portions of soil embankments and concrete culverts, away. Locals have had to span the gaps with temporary fixes, such as the perilously thin board shown above.

Upon crossing the land bridge, we joined several other people, bicycles, and motorcycles in taking an overcrowded boat across the river. Paddles were given to about six passengers on the sides of the boat to maneuver it through the rapid current of the river to the Northern banks. This crossing location is one of the most used, and is known as Khuferry.

During the meeting Wednesday, the local government spoke of the dangers of these types of crossings, yet they are essential to those people living along the river. People have died from risking these crossings during periods of high water levels and strong currents, made worse by heavy loads. They plan to alert people to only make these crossings during the early daytime period.

Tour of Dykes with Ministry of Water Official - Wednesday

One major issue faced by the community is the loss of human life due to unsafe river crossings. Pictured above is a current crossing in use by local residents. The residents make use of an old, abandoned dyke in order to cross regularly flooded areas to the river, where a boat takes them across the rest of the way. The problem is that the dyke was abandoned for a reason – the ministry had constructed a river training here, and this dyke is now found at the convergence of the main river and the training, creating a confluence of rapid, unsafe water currents. Not only is this a very dangerous crossing for a boat to make, with dangers of capsizing, but also the dyke is prone to collapse as it is quickly being eroded away by the currents.

There are three primary causes of dyke failure: overtopping of the dyke by water due to inadequate height, undermining of the lower reaches of the dyke from water erosion, and holes within the dykes, caused by animals burrowing, people, or root structures which allow water to pass and eventually blow out the dyke. The primary methods in order to prevent the latter two are to construct the dykes by using filter media such as gabion baskets or stones.

If an area is prone to seepage, perhaps because it is the location of a natural stream, pipes are used in order to allow water to pass without undermining the dyke. Pictured above is an example of the use of gabion baskets. This is a portion of the same abandoned dyke from the previous picture, but due to the use of the gabion baskets it did last for over twenty years.

Although the Ministry lacks funds to construct a full bridge across the river, they are looking at options in order to facilitate people crossing the river safely. We all agreed that this would be the preferred location. People would still have to cross a river training (front) and the main river (back), but the current is much slower than at the former crossing. An old dyke would be rehabilitated in order to allow people to walk the rest of the distance to the northern shore.

The Ministry had a problem when trying to construct the downstream limits of the northern dyke last year – it had to be constructed through wetlands. Because of the geography, even though the area did dry out for a short period of time, the area proved impossible to construct a dyke, so the work had to end several hundred feet short.

The reason for extending the dyke further was to protect this school, Bukoma Primary School. For whatever reason, it was constructed on very low land, within the wetlands. Note the edge of the water located just twenty yards from the building. Because of the difficulty in building the dyke along the river, Madame envisions constructing a perimeter dyke immediately surrounding the school.