Determine the design characteristics of an urban 1.8 m diameter reinforced concrete pipe culvert with a square edge and headwall inlet carrying a 10-yr peak discharge rate of 6.0 m3/s. The following conditions prevail at the site if the culvert. The entrance loss coefficient ke is 0.5. The elevation of invert at the entrance is 29.87 m. The approximate length of culvert is 60 m. The slope of stream is 1.5 %. 

Determine the Head water (HW) at the culvert inlet.