Runon, sometimes they do hose down the LZ, sometimes they don't. It's hit or miss. In the area I fly, there is exactly one full-time professional fire department. The rest are volunteer, unpaid, part-timers with minimum training, doing it in their spare time to help the community, and we don't hassle them. We take what we get.
Crab, you seem to have never flown in a forested area, where the roads are lined with trees, trees are everywhere, and the power poles are mostly hidden in the trees. I recently landed in the middle of a major interstate highway for a wreck, and since the scene was near our base, we arrived before the fire department had a chance to set up an LZ and stop all the traffic, so we circled for some time while waiting. We had plenty of time to recon everything, and thought we saw a place where wires crossed the highway, but we couldn't be certain. We checked thoroughly, but couldn't see any wires. This was in broad daylight, mid-day. On final approach, we finally found the wires, the poles hidden in trees on each side of the highway, just one pair of wires in front of us. A normal fast approach would have resulted in our being in the middle of the highway with rotor blades and parts spread all over the place. You fly approaches your way over there, and I'll fly them my way here. I intend to retire alive.