Assignment 5: water systems

When applying for example a culvert, it is important to think about the function and the shape of the culvert. The aim is to allow water to flow from A to B. This is often based on calculations. Below are a number of tasks relating to art works. The necessary theory can be found in the PowerPoint presentation (see Appendices).

Assignment 5.1: Culvert

What is the flow rate through a fully filled culvert with a diameter of 800 mm, at a water level drop of 2 cm?

Assignment 5.2: Weir

What is the flow rate over a weir with an overflow width of 1.50 m?
The weir level is NAP +1.27 m and the crest height of the weir is NAP +1.15 m.
(NAP: acronym for Amsterdam Ordnance Datum -Dutch vertical water height reference system)


Assignment 5.3: Weir

What is the minimum overflow width of the weir?
Size of drainage area: 150 ha.
Regulating discharge: 1.33 l/s/ha.
Maximum height of overflow radius at regulated discharge: 26 cm. 

Assignment 5.4: Watercourse

What is the flow rate, and the velocity of flow if a watercourse has the following dimensions? 
Width of watercourse: 1.50 m.
Water depth: 1.00 m.
Slopes: 1:2
Overhang: 4 cm over 1 km.
Situation: Lightly vegetated (Km value: 26).


Assignment 5.5: Water balance

Is there any seepage or run-off in the area concerned? Calculate how much in mm/per day.

Size of area: 80 ha.
Period: 1 year.
Precipitation: 925 mm.
Evaporation: 488 mm.
Measured inflow through inlet is: 300,000 m3.
Measured discharge by way of a weir: 1,000,000 m3
Both level and groundwater levels are the same at the beginning and end of the period.