water leaks are largely due to hardened or cracked rubber seals, maybe misalligned of rubber seals.
Have it replaced and it should be fine. For minor seal issues, a good DIY with some silicone paste could fix it in a jiffy...
If you adjust the intermittence speed to max (fastest), you'll realize that it runs accordingly to the car's speed. When you idle, it will swipe every 1.5-2 secs interval. When you drive at a lower speed, it will...