Home-built drawdown instrument
If you can get to the top of the well you can measure the drawdown with a home-made setup. Procedure and parts as follows:
1. Drop a weighted line down the well to find the depth to water and the depth to the pump. DON'T lose the line.
2. Get a length of 1/4" OD plastic tube a bit longer than the depth to the pump. Get a 30 psi pressure gauge if water to pump is less than 70 feet, or 60 psi if water-to-pump is 70 to 140 feet. Also, get a bicycle pump or equivalent, and fittings/means with a Schrader valve to let you connect the pump and gauge to the top end of the tube at the same time.
3. Fasten a weight securely at the end of the tube and lower it down the well. A piece of 1/4" copper tubing about 4 feet long, attached to the plastic tube with a ferrule type union would be a good weight and would not take too much diameter. Make sure the ferrule union is securely connected to the plastic tube.
4. Lower the tube to the top of the pump and secure it at the top of the well, without kinks.
5. Using the bicycle pump, slowly pump air into the tube until it won't go any higher. Stop pumping and wait until the pressure becomes stable.
6. Read the pressure gauge. One psi is 2.31 ft of water above the end of the line.
7. Operate the water pump and record the pressure and time as the water goes down. As the water goes down, the air will escape out the end of the tube, reducing the pressure at the gauge.
8. Pump in a little more air and check it from time to time. Excess air will excape at the bottom.
If you want to do a flow test you can buy a water meter from USABlueBook (800-548-1234) for $30.72 + Shipping. It is Stock Number 62276 and has 1" male straight pipe threads on the ends. If you are going to install it permanently you will want to get two couplings Stock Number 48816 at $4.97 each. Shipping is usually UPS Ground from Chicago and will go out same day if you order by 5PM central time.