Hi Zeev,
In every case where I tag "bridge=low_water_crossing", there is a built-up cement or rock dam structure built on the roadway crossing the stream. Sometimes this cement/rock structure crosses through the water and in some cases it is over the water as a bridge like crossing. I would NEVER use this tagging for an ordinary track simply passing through the water. For that I simply give a "ford=yes" tag. I always look for cement on the crossing. Lastly, I never tag a situation where it is a pipe passing under the track and no cement overhead.
Are you telling me that here in Israel, no track/stream crossing qualifies as a low_water_crossing? 
(By the way: I will indeed remove the name tags.)