…but it pours, espe­cially in Pori­rua today, caus­ing sud­den flood­ing and ser­i­ous dis­rup­tion.

I down­loaded the hourly rain­fall data from Great­er Wel­ling­ton’s site (a rather pain­ful manu­al pro­cess, but a big improve­ment from not long ago, when you could only get the charts as stat­ic images) and put togeth­er a quick graph. Here are cumu­lat­ive rain­fall totals for today, for selec­ted sta­tions in the region arranged roughly from north to south.

Wellington region rainfall for 20160505

Unfor­tu­nately there’s no sta­tion in Pori­rua itself, but the one just upstream in Tawa received the greatest total. 60mm in a day is not a huge total in itself, but most of it came in two or three hours before 9am, peak­ing at a tor­ren­tial 20mm/hr. Met­Ser­vice’s radar caught the deluge at its height:

Taupo Stream (just north of Plim­mer­ton) also caught a good 50mm, and I sus­pect that there were very loc­al­ised falls in Pori­rua that were even high­er. I saw a few com­plaints on social media along the lines of “Typ­ic­al! A little bit of rain and the infra­struc­ture can­’t handle it”, but when you get half a month’s rain­fall in a couple of hours, most drain­age sys­tems would struggle to cope…especially in flood­plains and reclaimed mud­flats.