This is the pace chart for the 7 mile run that I did on the 11th July.

There are several massive drops where my pace goes to 20 minute miles, and it takes 3-4 minutes each time to get back to the pace it was before. I've looked at the distance markers and every single one of these are right at the time that I took planned water breaks. I'd slow down to a walk, get my bag off my shoulders, get my drink out, and keep walking until I'd used the planned amount of fluids for that stop.

So part of what I need to do is get faster at getting my drink out of my bag and drinking it, and doing it at speed, but walking isn't necessarily a bad thing. Even Runner's World endorse it as an extra tool to help manage your breathing and heart rate during races.  

The key quote, though, is this one. 

Just keep walk breaks brief: Most of the benefits accrue within 30 seconds to one minute

So getting my water breaks down to 1 minute will make a huge difference!