Dyke reinforcement Hagestein - Opheusden
Causes
Height
Primary river dykes along the Nederrijn and Lek do not meet requirements set for these watercourses. Some sections of the dyke have to be improved to pass (regular) safety tests.
Wherever river widening is impossible, A28 additional dyke reinforcement work will be carried out. Sections of the dyke along the rivers Lek and Nederrijn ZEIST between U T R E C H THagestein and Opheusden will be improved.
Stability (piping)
High water pressure is causing the top layer of the dyke to deteriorate. This weakens the dyke.
Water seeps under the dyke (seepage), taking sand with it (piping). This weakens the dyke and will lead to breaches.
The dyke is too low. At high water, the river water flows over the dyke.
Solutions
Stability
2. Construction
1. Dyke reinforcement in ground
3. Dyke reinforcement in ground
inwards
outwards
In principle, dyke reinforcement is done inwards. In case unfeasible due to i.e. A12 a lack of space, alternative measures will be taken in the order set out right.
A30 A50
W
E
1
A27
S
EDE
VEENENDAAL
HOUTEN
N
AmsterdamRijnkanaal Amsterdam-Rijnkanaal (channel)
Clay is being buried under surface level to create an impermeable layer. This will prevent groundwater from flowing under the dyke, preserving the stability of the dyke as a result.
A12 2 ELST
1
An L-wall is being constructed to reinforce the dyke because of the lack of space due to the historical buildings on either side of the dyke in Rijswijk (protected townscape).The L-wall is a concrete flood wall with cut-offs level at the driveways of the houses. WAGENINGEN
RHENEN
2 CULEMBORG
ELDEN
RIJSWIJK
Key to map:
ELST
A15
dyke reinforcement
A325
Waal
A2
(provincial) road
structure with L-wall
OPHEUSDEN
Lek
modified / new situation
motorway
ARNHEM
Nederrijn
Lek
‘text’
OOSTERBEEK
clay burying
2
TIEL
A50 1
Planning Project decision Preparation phase Start of project Delivering water safety
1 2 3 4
www.roomfortheriver.nl
Effect
1
2
2011
2012
Preventing or breach of N I J M Eflooding GEN the dyke during exceptional high water.
Maas WIJCHEN
A73
2013
3
4
2014
2015
Scale: 0
A50
5 km
Jan 2015 / 27-29-30