Still, the storm surge was both stronger and earlier than expected, apparently coming through waterways southeast of the city, said Col. Richard Wagenaar, the Army Corps of Engineers' district chief in New Orleans.
Even though the storm surge was both stronger and earlier than expected, it was not certain that it all came from the southeast. 
( z1 have-concession :ARG1 ( z2 know :polarity - :ARG1 ( z3 come :ARG1 ( z4 surge :ARG1 ( z5 storm ) :mod ( z6 all ) ) :ARG2 ( z7 southeast ) ) ) :ARG2 ( z8 and :op ( z9 strong :ARG1 z4 :ARG2-of ( z10 have-degree :ARG1 z4 :ARG3 ( z11 more ) ) ) :op ( z12 early :domain z4 :ARG2-of ( z13 have-degree :ARG1 z4 :ARG3 ( z14 more ) :ARG4 ( z15 expect ) ) ) ) )