Stormwater Drainage System
Stormwater pollution in Florida is regulated based on Federal Law and Agreements reached between the State of Florida and the Federal EPA. This program is called the National Pollution Discharge Elimination System (NPDES). The State of Florida works with individual Cities, or groups of cooperating cities, through a permit process. In Indian Shores, we operate with an individual 5-year permit with certain system operational requirements and reporting to the State of Florida every two years.
Stormwater pollution in Indian Shores comes from fewer sources than might be found in a larger city that is not located and zoned primarily residential like Indian Shores. The geography of Indian Shores is a narrow strip of land bordered on the West by the Gulf of Mexico and on the East by the Intracoastal Waterway, all within Pinellas County, Florida. The Town is essentially built-out with some properties now being redeveloped into 2 to 5 levels of residential units over parking. The Town only has two short streets and several beach access points that include a relatively small Municipal Separate Storm Sewer System (MS4). The larger road is Gulf Blvd. which is a State Highway that is about 2.6 miles in length. This road and its drainage system compose its own MS4 system operated by the Florida Department of Transportation (FDOT). The Town of Indian Shores has an Agreement with the FDOT to cooperate in efforts to maintain the systems that may join in the investigation of any illicit discharges that may happen. Part of Gulf Blvd. is 2-lane with pervious asphalt sidewalk and bike lanes. Part of this road is a divided 4-lane road. Speed limits on the 4-lane road section is 35 MPH and speed limits on all other roads in the Town are 30 MPH. There is very little Commercial types of development in the town and no gas stations and no industrial operations. The vast majority of all drainage systems, including outfalls in Indian Shores, are on private property and operated privately.
The primary potential for pollution of the surrounding waterways is as follows:
- Nitrogen and Phosphorus from fertilizer and lawn maintenance picked up by stormwater on private property that drains to the Intracoastal Waterway
- Erosion of the soil during construction of new buildings, seawalls and boat docks
- Deposition of materials over seawalls or on the beach by residents and visitors
- Illicit discharge of swimming pool water without dechlorination, car washing, and blowing of grass during lawn mowing into the Intracoastal Waterway over seawalls.
National Pollution Discharge Elimination System (NPDES)
Robert H. Brotherton, P.E.
The National Pollution Discharge Elimination System (NPDES) Permit for the Town of Indian Shores is specifically designed for the Town due to its small size and unique location on the beach. In Indian Shores, there are four (4) significant potential sources of pollution that can pollute our adjacent Intracoastal Waterway and Gulf of Mexico. These are: 1) Stormwater Pollution, 2) Soil Erosion from construction sites, 3) Swimming Pool water discharges, 4) and improper lawn maintenance.
Stormwater Pollution – A watershed is the area that collects rain water with a discharge to a receiving water body. In our case, 85% of all water in Indian Shores flows from the area near the sand dunes on the beach to the Intracoastal Waterway. Water that does not soak into the ground, flows east into storm drain inlets and pipes, across Gulf Blvd., and discharges into the Intracoastal Waterway through seawalls and in some cases through wetland areas. There are several things that can cause pollution from stormwater. As water flows across the surface of the land, the water picks up pollutants of many different kinds. These include pet waste, litter, overflowing trash cans debris, cigarette butts, plastic drinking water bottles and straws, and oil from cars dripping on the road and parking lots. Dumping of oil or other chemicals on the ground or into stormwater drains is not allowed. Dumping, blowing grass over a seawall, or grease leaking from a dumpster, are examples of an “Illicit Discharge” and will result in fines. No illicit discharges have been reported in recent months in Indian Shores. Only about 15% or less of rainfall in Indian Shores flows across the beach and directly into the Gulf of Mexico. Most but not all of this water is treated on private property prior to discharge.
Soil Erosion from Construction Sites – Totally keeping all soil on a construction site is not possible; however, the amount of soil tracked onto Town Streets and Gulf Boulevard can be reduced significantly by using proper erosion control methods. Proper sweeping clean-up and setting up the erosion control screens at the end of each work day is required to control erosion in Indian Shores.
Swimming Pool Water Discharges – Chlorine in pool water can cause very dangerous compounds when allowed to be discharged into water bodies. These compounds and the chlorine itself can be toxic to fish and other living things. Simply allowing a few weeks without adding additional chlorine to the pool will allow the chlorine to be dissipated and no chemicals will be required to dechlorinate the water. For quick removal of chlorine, insure that the proper chemicals are used. These chemicals can be purchased at any pool supply store.
Improper Lawn Maintenance – Proper lawn maintenance is the responsibility of the land owner. If not performed properly, bad practices by the landscape company can result in fines to the property owner. Proper lawn maintenance is the responsibility of the land owner. Ensure that the people doing the lawn maintenance know the rules of Pinellas County, which are also the rules adopted by the Town of Indian Shores. Landscape Companies that have been properly trained have the “Trained and Certified” oval-shaped seal on their equipment vehicles. Key issues are (a) Proper use of fertilizer (None between June 1 and Sep 30 of each year), (b) blow grass clippings and sand and leaves back into the yard after mowing, (c) do not allow grass clippings to be blown over the seawall, (d) set your sprinkler heads to spray water on the plants and grass and not on paved areas.
Indian Shores MS4 System
The Stormwater Drainage System for the Town of Indian Shores is a very small system and includes 17 components and 8 stormwater outfalls. These system components are described below:
- 186th Avenue West Beach Access – This component of the Town of Indian Shores MS4 system is a 30 foot wide pervious concrete surface road and parallel parking. The road surface slops from the beach toward Gulf Blvd.
- 186th Avenue East – This component of the Town of Indian Shores MS4 system is a pervious concrete surface access drive with 90 degree parking lot and picnic shelter.
- 190th Avenue West Beach Access - This component of the Town of Indian Shores MS4 system is a 40 foot wide pervious concrete surface drive with angle parking with overflow discharge into a treatment pond. The road surface slops toward the beach and into this pond.
- Nature Park - 191st East – This component of the Town of Indian Shores MS4 system is a small nature park with a parking lot and boardwalk trails that meander through wetland areas adjacent to the Intracoastal Waterway. The total upland portion of the site drains into a stormwater treatment pond with a skimmer. The pond then discharges through a seawall and into a wetland area through Outfall No. 1.
- Whispering Pines South – This component of the Town of Indian Shores MS4 system is composed of a short pipe collection system and CDS unit that treats the south half of Whispering Pines Drive and the west end of 191st Ave. A small stormwater pond treats the road area in the immediate vicinity of the pond and discharges under a skimmer into the CDS unit outfall. The outfall from this treatment system is through Outfall No 2 into the wetland area adjacent to the Nature Park.
- Second Street South – This component of the Town of Indian Shores MS4 system is composed of a short pipe collection system and CDS unit that treats the south half of Second Street and the east end of 191st Ave. The CDS unit discharges through Outfall No. 3 into the wetland area adjacent to the Nature Park.
- Town Square – This component of the Town of Indian Shores MS4 system is composed of a CDS unit located at the intersection of Second Street and 192nd Ave. East. The CDS unit discharges to a swale that is filled with Mangroves. The storm pipe system is submerged much of the time due to tidal conditions relative to the pipe elevations.
- Mangrove Swale – This component of the Town of Indian Shores MS4 system is composed of a CDS unit that treats the discharge from the Mangrove swale and discharges to the wetland area just south of the Public Services Building. This CDS unit and outfall No. 4 also includes the discharge from MS$ element 7 above.
- 193rd Avenue East and Town Pond No. 1 – This component of the Town of Indian Shores MS4 system is composed of a combined flow from a portion of the FDOT drainage system on Gulf Blvd. near the Town Hall property and flows to the east from Gulf Blvd. into outfall No. 5. Adjacent to this outfall is a stormwater treatment pond with an overflow into the same discharge pipe. A smaller pond treats drainage from the northeast portion of the Public Services Building parking lot.
- Town Hall Stormwater Treatment Pond(s) – This component of the Town of Indian Shores MS4 system is composed of two stormwater treatment ponds designed for the Town Hall property prior to the new Town Hall construction. Some reconfiguration and upgrades were made along with the new Town Hall construction. Discharge is through outfall No. 6 that goes through a seawall along the Intracoastal Waterway.
- 197th Avenue East – This component of the Town of Indian Shores MS4 system is composed of drainage from 197th Ave. along with some contributions from adjacent property into the street that is designed with an inverted crown with a concrete valley gutter down the center of the street. This discharges into a CDS treatment that then discharges through the seawall as Outfall No. 7.
- 197th Avenue West – This component of the Town of Indian Shores MS4 system is composed of drainage from 197th Ave. West and some adjacent private property that discharges to a stormwater treatment pond. This portion of 197th Ave. is constructed with pervious concrete pavement.
- Bay Place – This component of the Town of Indian Shores MS4 system is composed of drainage from both FDOT drainage in a pipe below the land surface and surface drainage that is the responsibility of the Town of Indian Shores. The FDOT drainage is directed through an FDOT owned CDS unit.
- 198th Avenue West – This component of the Town of Indian Shores MS4 system is composed of drainage from 198th Ave. West which is a very short street paved with pervious concrete. The slope of the street is to the west where excess water is directed into a stormwater treatment pond.
- 199th Avenue West – Same description as item 14 above.
- 200th Avenue West – This component of the Town of Indian Shores MS4 system is composed of a narrow right-of-way with a 4’wide sidewalk beach access. There is no outfall from this small grass area.
- La Concha Sidewalk – This component of the Town of Indian Shores MS4 system is composed of a narrow right-of-way with a 4’ wide sidewalk to the rear of the La Concha commercial property. Also within this Town right-of-way is an FDOT discharge pipe that discharges stormwater through an FDOT owned CDS unit.
Operations of the Town of Indian Shores MS4 System
The Town of Indian Shores continues to strive to reduce pollutant loads to the adjacent waters surrounding the Town through the following efforts:
- Education of the public including information provided on the Town Website and Beach Clean-up activities.
- Storm Sewer System Maintenance and Inspections.
- Recycling of materials like glass, plastic, and paper products that might otherwise be disposed in the adjacent waterways and beach. Collection facilities are also provided at all beach access points for proper disposal of waste materials on the beach.
- Practice of pollution prevention practices at all Town-owned facilities including proper fertilizer application practice on both Town-owned and private property.
- Regulation of illegal dumping and illicit discharges and waste disposal.
- Regulation of construction site erosion control.
Storm Sewer System Maintenance and Inspections
As previously described, the Town of Indian Shores has a very small MS4 system. Portions of these systems do deteriorate over time. In the saltwater environment, steel is very exposed to the saltwater environment with corrosion resulting. The grated inlet above, located on 191st Ave. was replaced earlier in the year 2015. The wooden skimmer will soon need to be replaced as even pressure treated wood will deteriorate over time. The MS4 system is inspected at least twice each year with notes taken as to required maintenance. These are formal inspections and weekly observations are made on much of the system due to other normal maintenance activity in the area.
In addition to the two beach clean-up events that the Town of Indian Shores sponsors each year, the Town works to provide education about the potential for stormwater pollution through the distribution of literature on racks at the entrance to Town Hall and the lobby of the Building Department. The Town also provides newsletters with articles about stormwater pollution including the proper time to apply fertilizer and how to perform proper lawn maintenance. Literature is also provided at the beach clean-up days for participants in these events.
An illicit discharge is any discharge of a fluid or other material into the Town’s stormwater system or directly into the Intracoastal Waterway that is not stormwater. Examples of such discharges are: elevator sump pumps pumped out onto the ground, water from a swimming pool that is not first had the chlorine removed, grass that is blown over the seawall from lawn mowing operations, grease that might flow out of a trash dumpster onto a Town street or parking lot, or any other number of things pumped or disposed of over a seawall or into the stormwater pipe system. It is everyone’s responsibility to report any suspected illicit discharge to Town Hall.
The Town of Indian Shores has custom built recycling center with a dedicated parking space for people to park while dropping off their recycled materials. Signs are provided that direct people into the center that was designed to be attractive and at the same time functional in a beach environment.The recycle center is located on 193rd Avenue East and behind the new Town Hall building.