With the warmer weather, the 'walkies duty' hasn't lifted. When going out for longer walks on hot days, I've been taking with me a bottle of water and a bowl. 

But I thought I'd ask - what's your 'rule of thumb' of how far you're going before you'd consider taking a dog drink with you? I've tended to assume up to about an hour walking, and 30m running/playing. Is this too long? (On a warm day)

And are there any better solutions to taking a backpack with water and a (fold up) bowl with us?