Public Works

Drainage

What is the Floodplain?

A floodplain is the lowland adjacent to a river, lake or creek.

Floodplains

Floodplains are designated by the frequency of the flood that is large enough to cover them, for example, the 10-year, 25-year or 100-year floodplain. Flood frequencies are determined by plotting a graph of the size of all known floods for an area and determining how often floods of a particular size occur.

Another way of expressing the flood frequency is the chance of occurrence in a given year, which is the percentage of the probability of flooding each year. For example, the 100-year flood has a 1% chance of occurring in any given year.

Most of the known floodplains in the U.S. have been mapped by the Flood Insurance Administration, one of the parts of the Federal Emergency Management Agency. Copies of all of these maps for Independence are kept by Public Works.

Anyone can purchase flood insurance, whether their property is in the floodplain or not, so check with your insurance agent. 

Land Disturbance

Land Disturbance is any activity that changes the conditions of land form, vegetation, creates bare soil, or otherwise may cause erosion or sedimentation. Activities include clearing, grubbing, removal of vegetation, stripping, excavating, filling, and storing materials. 

A permit is required if more than 50 cubic yards of dirt will be moved. The fee for the permit is dependent on the number of cubic yards to be moved.

Permits may be required for clearing and grubbing work depending on the size and type of work being done. 

Stormwater Management

Stormwater is any water that is not soaked into the ground after precipitation. When water is absorbed into soil, it is filtered and flows into streams or rivers. 

In developed areas, impervious materials such as pavement and buildings prevent water from naturally infiltrating into the ground. Water runs rapidly into storm drains and ditches and can cause erosion, flooding, and infrastructure damage. 

Stormwater management is the effort to reduce runoff and remove pollutants to protect our watersheds. Public Works provides an Stormwater Management Manual explaining proper implementation for development. 

Stormwater Manual

Erosion Control

Erosion is the removal of soil particles by the flow of water.

Grading and clearing work can cause sediment to be deposited into the storm water system, an open drainage channel, onto a neighbor's property or in the public right-of-way. The City requires erosion control measures such as berms, swales, and straw bales along with silt fences be installed in accordance with City Code for all new construction and demolition projects.

Public Works provides an Erosion Control Manual explaining proper installation of the various erosion control measures.

Erosion and Sediment Control Manual

Roadside Ditching

Ditches are the property owner's responsibility to maintain. Re-grading ditches or any other construction on ditches in the right-of-way requires a Right-of-Way Permit. 

Driveway Pipes

Property owners are responsible for cleaning and maintaining driveway pipes. Driveway pipes are generally in the right-of-way, so replacement requires a Right-of-Way Permit. 

Crossroad Pipes

The City cleans and replaces crossroad pipes. Curbs and gutters are the property owner's responsibility to maintain. 

Drainage on Your Property

To protect your basement from flooding, the ground should slope away from your house. Downspouts should drain away from the house's foundation but should not drain onto your neighbor's property. 

Septic Systems

Private Wastewater Disposal systems are installed in areas where no public sewers are available. New lots must be at least 3 acres for a septic system. A permit is required for all new systems and repairs to existing systems. Systems are inspected to ensure compliance with Missouri Department of Health rules.