l ose peoe have to li somhere, anthey ar't cessari going tbeiving in hazd-free olow-haza areas. nartor: citielike houst have seen their suburbs expand as urban land becomes scarcer. it'here thayou findome of the poest home the cit won: it waprobably few daysrior tthe stormaking andfall at we reived ales nd warnis to prere for theurricaneso i prey much wasreparingor a wintorm. and they told us we was gonna have a sstantial amounof rain, but couldn't image the amount of rain that we received. narrator: the waters of lake houston, a reservoir to the northeast of the city, were calm today, but in august 2017, an extraordinary 17 inches of ra fell in ls than a d. the risg watershreatene affent lakede homesuilt o landesignat as flooplain, lad tended tprotect th ty. to savthem, thflood gatere opene devastang poormostly bck neighrhoods downstream. the water pidlrose to ov 30 feet. dris still rks its psage. trically, entire family was sweptaw in the torrent. woman: the water was coming down l the wall it was ming own in mbedroom.nd it wa ust wateeverywhere. was just--itust happed so fa.