Every change in Dota 2 patch 7.31b, straight from Valve's official notes: 17 heroes, 2 items and 1 neutral item changed. Hero and item names link to their current stats.
Now triggers on Naga and all of her illusions every 6 attacks from Naga and her illusions combined (enemies hit by multiple rip tides only receive 1 instance of damage)
Damage decreased from 40/50/60/70 to 40/45/50/55
Talents
Level 10 Talent +20 Rip Tide Damage increased to +30