Flood Control and Water Conservation

The Flood Control District's primary activity revolves around the Chester flood channel and levee maintenance.

Flood Preparation 

While the County and other agencies work hard to prepare for inclement weather, flooding can still happen. Residents and business owners should take some time while the sun is still out to evaluate the need for flood insurance, permanent drainage improvements on their property, and last-minute emergency actions such as sandbags and timber deflectors.

Fires in our watersheds can amplify the need to prepare and prepare early. Fires have impacted watersheds in our County for decades. A burned watershed creates a new dynamic that should heighten everyone's awareness. While in many cases, flooding occurs from sustained rainfall over days that triggers flood flows, a burned watershed can yield the same result, or worse, with a single rainfall that would otherwise not even cause runoff.


A 100-year flood occurs only once every 100 years. 

The 100-year flood is a climactic average; there is a 1% chance that a 100-year flood will occur in any given year. 

Flash floods mainly occur in the eastern United States. 

Flash floods occur in all 50 states, including Alaska and Hawaii.

Flash floods occur only along flowing streams. 

Flash floods can occur in dry arroyos and urban areas where no streams are present. 

Flash floods occur mainly in the late afternoon and evening. 

Many flash floods occur at night. 

Homeowners' insurance policies cover flooding. 

Unfortunately, many homeowners do not find out until it is too late that their policies do not cover flooding.
Contact your insurance company or agent to buy flood insurance. 

You can't buy flood insurance if your property has been flooded. 

You are still eligible to purchase flood insurance after your home, apartment, or business has been flooded, provided your community is participating in the National Flood Insurance Program. 

Larger vehicles, such as SUVs and pickups, are safe to drive through flood waters. 

Two feet of rushing water can carry away most vehicles including SUVs and pickups

National Flood Insurance Quick Guide (PDF)


Sandbags, when properly filled and placed, will redirect storm and debris flows away from property improvements.


  1. Fill sandbags one-half full.  Sand is suggested if readily available; however, sand is not mandatory, any local soil may be used. 
  2. For a more durable bag with increased effective life, mix 10 parts of sand or soil with 1 part of cement.  The materials can be mixed and placed dry.  After all of the bags are in place, a light sprinkling of water is recommended.  This technique is only effective with burlap sandbags and will not work with plastic sandbags.    


Fold the top of the sandbag down and rest the bag on its folded top.

 It is important to place bags with the folded top toward the upstream or uphill direction to prevent bags from opening when water runs by them.

Care should be taken to stack sandbags in accordance with the illustrations.  Place each sandbag as shown, completing each layer prior to starting the next layer.  Limit placement to two layers, unless a building is used as a backing, or sandbags are pyramided.


  1. Sandbags will not seal out water.    
  2. Sand and soil-filled burlap sandbags deteriorate when exposed for several months to continued wetting and drying.  If bags are placed too early, they may not be effective when needed.    
  3. Sandbags are basically for low-flow protection (up to 2 feet).  Protection from higher flows requires a more permanent type of structure.    


 Do not use straw or bales of hay in lieu of sandbags.  They do not perform as well as sandbags and may be washed away.