FIXED!!
added xsecs
South Louisiana. Have a single 1200 acre watershed with a meandering ditch turning into a canal that goes through 2 84″ culverts under a road. The WSE is way high. For boundary conditions, I am using a flow hydrogragh for 10 yr storm, peak cfs ~850cfs. When computing there are very many computation messages in black ink about max. iterations of 20 with errors. with a couple of warnings in red about extrapoloated above section and culvert. Max xsec wsel error 14.505. Sections look good. Should be simple. Maybe more xsecs? They are generally between 1000 and 1500 feet apart.
And the beginning wse is (edited) 98 where the ground is 58.