The City of Summerville says that they are providing sandbags are available for anyone that needs them. 

From the City of Summerville:

Due to the weather prediction for the weekend, supplies for filling sandbags are available at the garage on Henry St for anyone in need. Sand and bags are available. You will need to fill you own bags.

Latest weather forecast from the National Weather Service:

Today
Showers likely, mainly before 3pm. Mostly cloudy, with a high near 75. East wind around 5 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Tonight
A 40 percent chance of showers, mainly after 10pm. Mostly cloudy, with a low around 69. Northeast wind around 5 mph becoming calm after midnight.
Sunday
Showers likely, mainly after 3pm. Partly sunny, with a high near 83. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 60%.
Sunday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms, mainly between 8pm and 2am. Mostly cloudy, with a low around 67. South wind around 5 mph. Chance of precipitation is 60%.
Monday
A slight chance of showers and thunderstorms before 8am, then a slight chance of showers between 8am and 2pm, then a chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 80. West wind around 5 mph. Chance of precipitation is 30%.
Monday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly clear, with a low around 57.