Funding
Sand Filter Grant - The objective of this project is to evaluate the effectiveness of the modified version of the Delaware Sand Filter to address non-point source pollutants present in stormwater runoff using various media readily available in the State of Georgia. The City has been an active participant in evaluating various BMPs to improve the water quality and biologic diversity of streams and rivers in Georgia.

The City will evaluate these modified Delaware Sand Filter systems for use in retrofit situation in urbanized areas by installing a portion of the filters using its own personnel and resources and installing the remaining systems by a contractor selected through competitive bid. This study will be conducted in a select area in the Potato Creek watershed. The City will use the collected data to conduct a cost benefit analysis of the modified Delaware Sand Filters.
Abstract | Application

STIP - The Stormwater and Transportation Improvement Program (STIP) is funded by the Special Purpose Local Option Sales Tax (SPLOST) Program “voted in” by the citizens of Spalding County and the City of Griffin in 1996. Revenues from SPLOST are utilized by the County and the City for the design and construction of infrastructure improvement projects related to stormwater management and transportation.

GEFA - The City of Griffin secured the first State Revolving Fund (SRF) loan specifically for stormwater improvement projects in 1997. The SRF loan was secured through the Georgia Environmental Facilities Authority (GEFA) which provides low interest loans to assist with the design and construction of capital improvement projects. The City submitted a comprehensive application and package to GEFA in order to secure the funding.

GEMA - The City submitted a comprehensive application to the Georgia Emergency Management Agency (GEMA) for a Hazardous Mitigation Grant to construct drainage improvements in the Lyndon Basin. The City was successful in securing grant funds from GEMA to assist with the design and construction.

Georgia DNR 319 Grant - The City submitted a comprehensive application package to the Georgia EPD for evaluation against applications for potential projects submitted by other municipalities. The City was successful in securing funds from the EPD to assist with the design and construction.

5th Street & Wall Street Drainage Improvements
The objective of this project has been to correct an improperly operating stormwater drainage system. The existing piping system is undersized which results in inadequate operation and flooding of areas between Taylor Street, Solomon Street, Fourth Street and Fifth Street. The proposed design calls for rerouting of stormwater beginning at the intersection of 5th Street and Wall Street and continuing east to an existing creek. The proposed design includes installation of a 72-inch aluminized corrugated metal pipe that replaced the existing undersized storm piping system. Additionally, a detention/ water quality pond has been constructed at the outfall of the pipe to reduce the flooding and non-point source pollution impacts downstream of the project. Funds secured from GEFA have been used for design and construction of this project.

Water Shed Basin Details – This project is located in the Potato Creek Basin. The stormwater runoff discharges into Grape Creek and ultimately to Potato Creek. Stormwater runoff from this street flows southeast for 1,700 feet via Grape Creek until its confluence with Ison Branch. The two creeks then become Potato Creek which flows to the south. Potato Creek flows south for approximately 25 miles until its confluence with the Flint River in Talbot County.

Bacterial Source Tracking
The City is conducting some preliminary sampling in the entire Potato Creek Watershed as part of the development of a Bacterial Source Tracking (BST) Program. Potato Creek is listed by the Georgia Environmental Protection Division of the Department of Natural Resources as an "impaired" stream due to excessive fecal coliform pollution. However, it is almost impossible to identify the source of fecal coliform pollution. Therefore, new technology is being developed that can identify bacterial pollution sources. The City is working with the University of Georgia, a leader in BST technology, to develop a practical application in the Potato Creek Watershed. This preliminary sampling will help to define future sampling areas as part of a Total Maximum Daily Load (TMDL) Implementation Plan for the watershed that applies the BST technology for cost-effective and focused water quality improvements. The Implementation Plan is currently under consideration by the EPA for funding under the Clean Water Act Section 319(h).
319 Grant Application - Bacterial Source Tracking In The Potato Creek Watershed
319 Grant Final Report - Bacterial Source Tracking In The Potato Creek Watershed

Carriage Hills Subdivision Drainage & Road Improvements
The objective of this project has been to address two related problems associated with the condition of two streets within the subdivision, Carriage Hills Drive and Carriage Trace. The asphalt pavement throughout the two streets had extensive damage and was in need of significant repairs. The cause of the damaged pavement related to existing poor soil conditions and inadequate surface drainage/stormwater conveyance. The drainage problems exacerbated the pavement damage by allowing surface water intrusion into the pavement section and underlying subgrade. This condition resulted in degradation of the underlying fill materials and damage to the surface pavement. The proposed design repaired the damaged pavement and corrected the existing drainage problems. Additional inlets were constructed in addition to increasing the slope of the roads to compliment the storm design. By addressing both issues in conjunction with one another, the City anticipates improvement with site drainage and long term performance of the new pavement. Funds secured from GEFA have been used for design and construction of this project.

Water Shed Basin Details – This project is located in the Flint River Basin. The stormwater runoff discharges into Shoal Creek to Wildcat Creek and ultimately to the Flint River. Stormwater runoff from this development flows northwest approximately 1,000 feet in an unnamed tributary until its confluence with Shoal Creek. Shoal Creek then flows west for several miles until its confluence with Heads Creek where it becomes Wildcat Creek. Wildcat Creek flows west until its confluence with the Flint River.

GIS Mapping / Inventory Collection
The City of Griffin is the first city in Georgia to develop a Geographic Information System (GIS) database by compiling an inventory of all stormwater drainage structures/features (both natural and manmade attributes) within the City limits. The GIS database contains information concerning the infrastructure system as well as tax parcel information, topographic information, land use information (March 2001), and aerial photography. A current project, which the City of Griffin Stormwater Department has under taken, is the Stormwater Inventory Program. The City has taken a physical inventory of the entire stormwater infrastructure both natural and man-made attributes of the city. This process includes taking measurements on structures such as curb inlets, grate inlets, junction boxes, headwalls and all associated pipes. Measurements include such data as the width of the grates found throughout the city as well as the shape, size and type of piping running between the structures. Following the measurement of the structure, the location of the structures are located based on state plane coordinates to centimeter level accuracy using the Global Positioning System. The Global Positioning System or GPS is a surveying system in which a radio receiver mounted in a backpack reads signals from a constellation of Department of Defense satellites orbiting the planet every 12 hours and interprets these signals into an exact location on the earth. Finally having obtained attributes and locations on these structures, a digital photo is taken of each structure. Once the fieldwork is complete, the data is then converted into a Geographic Information System database. The Geographic Information System or GIS database is computer system in which information is displayed graphically by location. The City is currently in the process of using the GIS to identify existing problems as follows: predict future problems; evaluate opportunities for enhancement of stormwater use; and develop cost estimates for construction as well as assigning priorities for infrastructure improvement.

Lyndon Avenue Drainage Improvements
The 652-acre drainage basin that comprises the project area is referred to as the Lyndon Avenue Drainage Basin. The existing conditions at the intersection of Lyndon Avenue and North Expressway results in flood waters rising to an elevation sufficient to create a hazard along North Expressway. Additionally, three areas along Lyndon Avenue and North Expressway experience periodic flooding such that the City of Griffin has posted warning signs to warn residents of flooding hazards within the area. The City of Griffin is actively working with the Georgia DOT to alleviate the flooding problems in the area. The City of Griffin is responsible for overall drainage and conveyance of stormwater for the entire basin, and for stormwater conveyance west of North Expressway through the old Wal-Mart parking lot. The Georgia DOT has responsibility for stormwater conveyance under North Expressway. The proposed project involves three distinct phases. The first phase of the project involved replacement of the two undersized 66-inch pipes by the City under the shopping center property. This work has been completed using grant funds provided by GEMA. The second phase of the project will involve installation of a two additional 6’ x 6’ concrete box culverts under North Expressway by the Georgia DOT to ensure unencumbered conveyance of stormwater flow under North Expressway. The Georgia DOT will provide all funding for the second phase of the project. The final phase of this project will be performed by the City at a later time. The City intends to replace, retrofit, and upgrade the existing pipe network within the Lyndon Basin. One portion of this project is detailed above as the North Lyndon Basin Drainage Improvements Project. Once all phases of the project are complete, potential hazards associated with surface water flow inundating the area roads should be minimized.

MacArthur Drive Drainage Improvements
The objective of this design has been to improve the flow of stormwater runoff through a residential area. Previously, stormwater runoff flowed overland through an undefined earthen channel with minimal slope. The channel had shown a tendency to flood the surrounding residential areas under moderate to heavy storm events. The proposed construction consisted of redefining the existing channel and installing a minimal amount of piping. The City believed that since the area was originally a naturally flowing channel, it was important to construct an improvement that did not consist of piping only. Utilization of an earthen channel had several aesthetic benefits, but it also had environmental benefits as well. Research by the City and its design engineers showed that earthen channels can improve water quality through natural filtration methods. The stormwater from the improved system discharges to the same location as the earthen channel previously did. Funds secured from GEFA have been used for design and construction of this project.

Water Shed Basin Details – This project is located in the Potato Creek Basin. The stormwater runoff discharges into Grape Creek and ultimately to Potato Creek. Stormwater runoff from this street flows east via an unnamed tributary until its confluence with Grape Creek. Grape Creek then flows 200 feet south until its confluence with Ison Branch where the two creeks become Potato Creek. Potato Creek flows south for approximately 25 miles until its confluence with the Flint River in Talbot County.

North Griffin Basin Water Quality Enhancement
This phase of the North Griffin Detention Pond project will involved construction of a bio-engineering system within the pond itself and within the existing forested wetland area downstream of the pond. The bio-engineering system within the pond promotes initial breakdown of contaminants present in the stormwater runoff followed by further breakdown of the contaminants as the stormwater runoff flows through the existing wetland area downstream of the pond. The bio-engineering system for this type of project involves planting selected species of vegetation to naturally “filter” the water and assist in the breakdown and removal of sediments, contaminants, and pollutants from the runoff water. The bio-engineering system offers other potential advantages, including simple operation with low maintenance; process stability under varying environmental conditions; and relatively low construction and operating costs when compared to traditional water treatment facilities. Additionally, the introduction of emergent wetland species will also result in improvement of wildlife habitat while at the same time providing water quality enhancement. The ultimate benefit of the bio-engineering system will be to improve water quality in Shoal Creek which discharges into the Flint River.

North Griffin Regional Detention Pond
The North Griffin Regional Detention Pond was constructed in 1998 to improve stormwater quality draining from the north Griffin drainage basin. The 4-acre pond is located just west of Highway 19/41 and south of Highway 92. The pond provides detention for approximately 90% of the upstream basin thus eliminating downstream flooding (particularly within the Waterford Subdivision) while at the same time utilizing a natural wetland system to provide water quality enhancement for approximately 95% of the basin. The second phase of this project involves construction of a bio-engineering system (spring of 1999) within the pond itself and within the existing forested wetland area downstream of the pond. The bio-engineering system phase of the project is detailed in the section entitled “North Griffin Basin Water Quality Enhancement”. The pond holds stormwater draining from the basin in a planted wetlands pond and releases the water slowly into an established forested wetland. Once it exits the site, it enters a tributary to the Flint River. The wetlands and detention action of the pond assist in the removal and treatment of various pollutants in the stormwater. The established forested wetland acts as an additional pollutant filter. The pond has been effective in reducing some pollutants by 90 percent. Each quarter, the City of Griffin is required by the State of Georgia, Environmental Protection Division (EPD), to sample the water in the pond system. Four sample locations are sampled every quarter to demonstrate the effectiveness of the pollutant removal efficiency of the system. Several funding mechanisms have assisted the City of Griffin in the design and construction of this project. Revenues from the SPLOST funded construction; a grant from the Georgia EPD Section 319(h) Grant Program funded the bio-engineering phase of the project; and funds from the City of Griffin’s Stormwater Utility are being used for detention pond maintenance.

Project Status - Sampling was conducted this quarter (September 22nd) after a rainfall event of 1.01 inches. The samples were analyzed and presented in a technical report to Georgia EPD. The report summarized the results of the sampling event and provided a trend report of past sampling events.
Quarterly Report | Final Report | Map of Project

North Lyndon Basin Drainage Improvements
The purpose of this project is to improve the stormwater drainage through the entire 138-acre basin. The drainage basin conveys stormwater via a combination of open earthen channels and a piping network. Most of the existing piping network will be replaced due to its existing poor condition, and selected pipes will be upsized to handle the volume of runoff. Funds secured from GEFA will be used for design and construction of this project.

Water Shed Basin Details – This project is located in the Flint River Basin. The stormwater runoff discharges into the Shoal Creek to Wildcat Creek and ultimately to the Flint River. Stormwater runoff from this basin flows west approximately 1,000 feet in an unnamed tributary until its confluence with Shoal Creek. Shoal Creek then flows west for several miles until its confluence with Heads Creek where it becomes Wildcat Creek. Wildcat Creek flows west until its confluence with the Flint River.

Oakdale/Evergreen Subdivision Drainage Improvements
The objective of this design is to improve the flow of stormwater runoff through two residential subdivisions. The existing drainage system is a combination of pipes and open earthen channels. Several of the pipes and channels are undersized and selected drop inlets have not been constructed at the proper elevation. The resulting effect is that the entire drainage system does not function properly and periodic flooding of certain areas is common. The proposed design will replace several areas of undersized pipe networks with a new multi-barrel aluminized steel corrugated metal pipe system. Additionally, areas of erosion due to high exit velocities associated with the undersized pipe systems will also be rehabilitated. The proposed design will eliminate a majority of the open channel flow except for the portion that connects the two subdivisions, and the existing channels will be replaced with a properly sized piping system. Several raised lid inlets will be added at the correct invert elevations in selected locations to improve the overall drainage throughout the area. Some drop inlets and catch basins will be replaced with double wing catch basins. Funds secured from GEFA will be used for design and construction of this project.
Water Shed Basin Details – This project is located in the Flint River Basin. The stormwater runoff discharges into Shoal Creek to Wildcat Creek and ultimately to the Flint River. Stormwater runoff from this development flows northwest (through Carriage Hills Subdivision) approximately 1,300 feet in an unnamed tributary until its confluence with Shoal Creek. Shoal Creek then flows west for several miles until its confluence with Heads Creek where it becomes Wildcat Creek. Wildcat Creek flows west until its confluence with the Flint River.
Overview Presentation



Oakview Drainage Improvement
The Heads Creek Basin within the City of Griffin consists of 178.6 acres of primarily commercial and medium to high-density residential development. The project site is located in the northwest quadrant of the City approximately one-third of a mile northwest of the intersection of State Route 92 and US Highway 19/41. The Oakview Drainage Improvement Project consists of retrofitting an existing stormwater detention pond that currently provides detention for 55 acres of commercial and multi-family residential development located within the City of Griffin. The anticipated non-point source pollutants originating within the project site would fall under the category of urban runoff. Land use studies for the project area indicate that the impervious area accounts for approximately 75% of the basin. The existing detention pond is currently undersized and does not provide the desired level of flood control for the downstream property owners that are located in both the City and Spalding County. As a result, the City of Griffin and Spalding County jointly undertook the task of re-designing the existing pond and the downstream drainage network to the appropriate engineering standards. At the same time, the City saw an opportunity to incorporate a water quality enhancement component into the re-designed pond that ultimately resulted in a comprehensive design that addresses both flood control and water quality protection. Finally, protection of this watershed is in the best interests of both the City and the County. This is based on the fact that the Heads Creek Reservoir is located approximately tree miles west of the project area and provides drinking water for all of Spalding County and the City of Griffin. Project Status - The project is scheduled for construction in Spring of 2001 pending funding. The primary funding sources include: The City of Griffin – Office of Public Works – Stormwater Utility Division, United States Environmental Protection Agency, Georgia Department of Natural Resources (Nonpoint Source Program), Georgia Department of Natural Resources (Water Quality Program), Spalding County and Georgia Department of Transportation.
Final Report

Pine Hill Road



Stormwater Master Planning
The City of Griffin is one of the first cities (and the only city of its size) in Georgia to develop a Geographic Information System (GIS) data base by compiling an inventory of all stormwater drainage structures/features within the City limits. The City is currently in the process of using Stormwater Master Planning to identify existing problems, predict future problems, evaluate opportunities for enhancement of stormwater use, develop cost estimates for construction as well as assigning priorities for infrastructure improvement. Master planning involves using computers to simulate rainfall on an area, determine the quantity of stormwater runoff, analysis of conveyance systems efficiency, and implementation of system improvements to reduce flooding. With the establishment of the National Pollutant Discharge Elimination System (NPDES) portion of the Clean Water Act, more and more masterplans are including an analysis of non-point source pollution and water quality analysis. Hydraulic models are used to determine flow elevations, velocities, distribution and pressures using flow rates and boundary characteristics as inputs. Hydrologic models are used to determine flow rates at various points throughout a watershed or pipe network given the typical inputs of rainfall, basin characteristics and basin structure. As important as master plans are to any comprehensive storm water program, by themselves they will not solve problems or prevent flooding, drainage or water quality problems. The master plans represent a blue print for action that must be taken if these problems are to be solved or prevented. Too often, people see the master plan as the end product and forget that if the plans are not integrated and implemented together, little good will result from the completed work. The real work begins when the master plan is complete.

TEA-21
The TEA-21 project is a stormwater quality improvement study to assess stormwater quality in an urban highway corridor, engineer and emplace stormwater quality improvement technologies (best management practices), and re-assess stormwater quality after those technologies have been implemented into the study area. The project is jointly funded through the City of Griffin Stormwater Utility, and a Georgia State Department of Transportation (DOT) grant. The TEA-21 project location selected was Georgia State Highway 16. The study area spans from Hill Street to the City of Griffin Library, along the Highway 16 corridor (Taylor Street) (please see project overview map). The results of this study will allow the DOT to provide the selected technologies as alternative technologies for reducing stormwater pollution in future highway development projects for the State of Georgia. Stormwater quality will be assessed through the winter of 2000/2001 to provide the baseline data for the study. Once that data has been analyzed, the specific pollutants of concern within the study area will be known. At that point, the City of Griffin will select the technologies which best reduce the pollutants of concern for Highway 16. In the summer of 2001, these technologies will be engineered and constructed within the highway stormwater infrastructure. Subsequent rain events (through the fall and winter of 2001/2002) will provide the data, which should demonstrate the reduction of the identified pollutants of concern. This data will be published in a technical report and presented to the DOT. The ultimate goal of the study is the improvement of stormwater quality entering our rivers and streams, thus improving the quality of life of the citizens of the State of Georgia and our natural environment.

Project Update - This summer and fall, the City of Griffin has conducted a series of meetings with industry leaders wishing to include their stormwater improvement technologies in the project. Over fifteen companies have provided technical data to the City of Griffin in an effort to demonstrate the effectiveness of their technologies. Initial baseline water quality sampling is currently being planned for this fall/winter.
Final Report | Map of Project