Hydraulic control of Shatt al-Hilla within Hilla City

Abstract EN

The distance on Shatt Al–Hilla between (km 32.000) and (km 51.500), denoted hereafter as "the reach", is where it crosses Hilla City.

The approved development plan of Shatt Al-Hilla involves increasing its design discharge from (230 m3 / s) to (303 m3 / s).

This will cause raising its normal water level within the reach by about (0.73 m) which will endanger some important localities in the city.

The research aims at examining the extent of effectiveness of some practical physical and hydraulic measures to control the flow in the reach, so that the expected danger will be minimized, if not eliminated.

The examined measures were deepening the reach, increasing the side slope, increasing the bed width, increasing the bed slope, decreasing the equivalent Manning’s (n), a combination of increments in bed width, flow depth, and side slope, and taking use a proposed cross regulator at the upstream end of the reach and the operation of Dora cross – regulator at the downstream end as hydraulic control measures.

The research showed that the most appropriate practical solutions, from a hydraulic point of view, would be deepening the reach by (0.35 m) or decreasing Manning’s (n) to (0.0294) or constructing the proposed cross regulator at km (32.200) and operating it such that the (303 m3 / sec) discharge will produce a water level downstream the regulator of (29.00 m.a.s.l).