CaspiCement is in the process of constructing a greenfield cement plant near the village of Shetpe, Mangystau Region, Kazakhstan. During heavy rainfalls it appeared that the constructed drainage system is not working properly, as:
- the rainfall runoff water in the surrounding of the plant flows to the trenches (the permeability of the soil is low)
- the soil of the trenches is eroded by the water flow (the top soil layer consists of very fine material)
- the culverts were filled up with eroded materials
- natural ditches and underground piping occurred causing soil instability (under the fine material there is a layer of coarse material).
Witteveen+Bos has completed a drainage study by:
- Assessment of the local hydrological situation
- Determination of the critical surface levels at the plant
- Determination on flow speeds, where additional stability measures are needed to prevent erosion
- Advice for a representative storm situation for the design on basis of general information and pragmatic assessment
- Calculating the existing situation by Sobek Rainfall Run-off (RR) and Sobek Channel Flow (CF) as a reference for the initial situation (on basis of the preliminary site grading plan) to assess the current problems
- Selecting a mitigation measure plan calculated and optimized with Sobek RR en CF
- Concept design of the drainage system introducing modified and new trenches and culverts, several new weirs and a storm water collection basin.