Dike protection: Daily half marathon for the inspectors

Dikes stretch for kilometers to protect land and people from flooding. Small damages can turn into major catastrophes. To ensure that this doesn’t happen, dike inspectors drain them. An example from Lower Saxony

At the Huntedeich in Wardenburg in the Oldenburg district, Thomas Schlunck and the volunteers from the Technical Relief Organization (THW) have so far successfully prevented the dike from breaking. Now it’s freezing. Actually good news for the dike protector. However, he is now annoyed by moles.

The crack is three centimeters wide and a good ten centimeters deep. “There has been a slump here,” explains Thomas Schlunck, carefully holding the ruler into the damaged area. “We are losing dike safety here.” The 64-year-old stands on the Huntedeich with the THW volunteers and assesses the damage. Even a layperson can see that the turf has given way and has slid a little deeper towards the water. To ensure that the dike does not sink any further at this point and thereby lose its protective function, the helpers stabilized it with sandbags.

Control rounds around the clock

Thomas Schlunck spent Christmas Eve with his family under the Christmas tree in Emden. The next morning at six he set off towards the flood area. Since then, the specialist and technical advisor for dike defense and flood protection – his official title – has been taking care of the safety of the Huntedeich in the Oldenburg district.

Extreme flooding and days of rain have turned the dike into a soft mass. Schlunck and his team check a seven-kilometer section of dike every two hours – around the clock. “We cover 21 kilometers during one shift,” says the dike expert, who is also a lecturer at the THW training center in Hoya. By the weekend, the volunteers will have walked a total of more than 1,000 kilometers.

The inspectors always walk through the structure in groups of two, examine the condition of the dike base and also check the bridges: trees and other flotsam can easily become jammed on the bridge pillars. “This is very dangerous because it hinders the flow of water and could damage the bridge structure,” says Schlunck.

Damage is recorded digitally

Every damage is documented on a digital map so that all dike runners can see which areas they need to pay particular attention to. The inspectors report the damage to the Hunte-Wasseracht, which is responsible for the dikes. Enno Kuhlmann, association technician at the water rescue service, can often give the all-clear, including at one point at the foot of the dike: an inspector had discovered a small fault in the ground. “In fact, the area looks like the beginning of a slump, but it is not dangerous,” explains Kuhlmann, who knows practically every meter of the dike and therefore also all the natural unevenness.

There is no fear that inland dikes will suddenly break and the water masses will rush into the hinterland. But after eight to twelve days of flooding, the structure is so soaked that cracks can appear. Mice and other animals that dig holes in the dike are also a problem. The moles at Huntedeich are currently very active.

Apparently they fled from the flooded pastures onto the dike. For Thomas Schlunck, this is a real nuisance: “We really don’t want moles here, their burrows make the dike unstable.” However, the animals cannot be driven away – Schlunck can only hope that they will soon disappear voluntarily.

Frost brought relaxation

The dike inspectors do their rounds in sub-zero temperatures for days. Still better than in rain and storms, like in the first week of flooding, thinks Thomas Schlunck. In addition, the frost at least stabilizes the outer layer of the dike.

The question is still what will happen when it thaws again. However, Schlunck and his colleagues are confident that the water level will have fallen further by then and that the water will press against the strained dike with less force. And if everything goes well and the water levels continue to fall as forecast, then Thomas Schlunck can now go home again. After almost three weeks of operation in the flood area.