A 1-foot fiberglass H Flume with a 13-foot long custom approach section.

Typically approach sections are 3 to 5 times the maximum anticiapted head (normally assumed to be the depth of the flume).  Here site requriements were such that the flume had to be located away from the feed channel - so a custom approach section was fabricated.  

To keep costs down the approach section was made in three pieces that bolt together in the field.