We connected a hose to our water heater which was really close to where we would be birthing. We filled it 1/2 way up with super hot water so it would stay hot for a while. Then as it got closer to me getting in, we filled it with colder water to even out the temp. That way we wouldn't run out of hot water too. We just bought a new garden hose to use.
To empty the tub we put one end of the water hose in the tub and ran the other end our the patio door down to the street. Kinda weird but, my husband sucked on the end of the hose for a little while to get it flowing and with the way water works, it emptied itself out once it got flowing. We only did this because my midwife forgot the pump. You can get a pump to help too. My midwife had them to rent. You can also put the other end of the hose into the toilet and it will go down without flushing.