Very true, here in Spain the two storm drains near me are called rivers but they are normally completely dry. In 2012 there was very heavy rain about 50 km away in the mountains (12 inches in about 3 hours) the drains/rivers filled and then overflowed, my house had a meter of water in it. In some places the water was 3 meters deep, the “rivers” were about 6 – 8 meters deep.
Sounds like "Send reinforcements …….