You want to show the water flowing, but the shutter speed is too fast, so it stops the water movement. Should you just give up on shooting with slow shutter speeds during the day?
This is where the ND (Neutral Density) filter is useful. It reduces the amount of light that enters the lens. There are various types of ND filters, such as the ND2, ND4 and ND8 (LUMIX optional accessory). The ND2 reduces the amount of light to 1/2, the ND4 reduces it to 1/4, and the ND8 reduces it to 1/8.