Thanks for the reply.
In answer to your question. You would leave the bucket or barrel in
place, and note the level of the water from the gound (for example).
Let's say 3 feet. You then walk around the yard with the other end of
the hose and take measurements between the water level in the end of
the hose, and the ground. Let's say we have 3'5". We then know that
we are at a spot on the ground that is 5" lower than then ground at the
A couple of notes...
You're right, you don't want to spill water as you are moving. The
typical kit that attaches to a garden hose has a clear tube with a
stopper that can be used when moving.
A while ago, I did some work in the basement and used a water level
without a reservoir. Again, I had the clear tubes from the kit on the
end of the hose. The bad thing was that the level at BOTH ends of the
hose would change as you walked around and distorted the hose. It was
a bit of a pain, as I would move the hose, then I would have to measure
both ends from the reference line that was at one end of the hose.
This is where the reservoir would be nice. The hose would still
distort as you move, but it would cause an insignificant change in
water volume when compared to the reservoir. Therefore, you don't have
to keep checking both ends.
On the end of the hose where you are walking around the yard, it is
best to attach it to a stick. You can then put the end of the stick on
the ground and stand there for a bit while the level settles. Then
take your measurement.
For me, this is a one-time use thing. Plus, I'm really cheap!