Water supply trench near foundations

[WWilts]

How close to existing foundations can a trench safely be? 
(water supply duct, assume 1m deep trench and 1m deep existing foundations)
Problem for the foundations?

[PeterW]

Water only needs to be 750mm and if it’s a meter away and dug with a 12” bucket it won’t cause any harm but watch out for services to the other house when digging 

[George]

If you're not undermining the foundations of then the risk is low.

 

However, in some circumstances you need to consider the footings can become a small retaining wall if you excavate the soil along one side so safest is to do it in stages, excavate a length, backfill, then the next section. It's a lot of 'it depends' - footing size, soil type etc but whenever you deal with ground conditions, excessive caution is never punished.