3. Research Background
3.1 Introduction to Stormwater Infrastructure
Correlation of Increased Urbanization and Water Systems
The effects of urbanization often result in a negative impact to water quality due to rapidly growing populations, landscape manipulation, waste material, dumping of chemicals and withdrawing water for peoples’ uses (USGS Website). In addition to this, in a 1997 article, Booth and Jackson along with Poff et al., concluded that human activities have the potential to cause changes to the environment via alteration of the land surface for various uses including light and heavy industry, urbanization and suburban development which has changed water pathways and induced changes to natural processes (Peters 2009).
At the early stage of urbanization, the United States Geological Survey (USGS) website noted that changes in land use, such as the removal of vegetation and addition of real estate with underground sewer systems or septic tanks occurred which resulted in more storm runoff and erosion due to less vegetation to slow the water (USGS Website). This resulted in more pollutants being washed into bodies of water along with flooding caused by poor water drainage. The USGS website went on to note that at the next phase of continuing urbanization, there were more additions of gray infrastructure such as underground pipe networks along with an increased amount of residential, commercial and industrial real estate. More buildings resulted in an increase of impervious surfaces like roads and parking lots. The USGS website concludes that due to these changes in land use the effect on the water system and correlating ecological systems will be as follows:
● The underground water table will have less water, thus lowering the water table,
● Some underground water wells will not be deep enough and will run dry,
● The runoff from the increased pavement will go into storm sewers then local streams,
● This excess runoff now going into the streams will cause flooding
● Excess flooding of the stream will not result in erosion along the stream banks,
● More sewage is discharged into streams that weren’t “designed by nature” to handle that much water.
● The use of too many large wells can lower the underground water table which can cause other wells to run dry
● Land that was formerly “held up” by underground water to subside can result in sinkholes and land subsidence.
Introduction & Challenges of Gray Infrastructure
Both gray and green infrastructure come with their respective ecological, economical, and political challenges. The economic challenges associated with gray infrastructure – human-engineered infrastructure for water resources such as water and wastewater treatment plants, pipelines, and reservoirs (Alberta Water Portal Society website, 2016) – include funding availability, public investment, maintenance, and inflexibility due to project size, construction requirements and finite restrictions. The ecological challenges associated with gray infrastructure are directly related to challenges previously mentioned to be associated with urbanization. The EPA website, which describes gray infrastructure as systems of gutters, pipes, and tunnels used to move stormwater away from where we live to treatment plants or straight to local water bodies, state that in many areas the gray infrastructure is aging while its existing capacity to manage large volumes of stormwater is decreasing in areas across the country.
Introduction and Challenges of Green Infrastructure
According to the Alberta Water website (2016), challenges associated with green infrastructure, a system of small-scale to larger scale elements integrated into sites which can be woven throughout a community providing habitat, flood protection, cleaner air, and cleaner water (Watershed Institute website, 2017), include uncertainty of risk, investment, and effectiveness in urban areas. In addition to this, the website also mentioned that due to green infrastructure projects not fitting traditional water treatment construction models, there may not be standards or building/urban codes to govern how projects should be implemented. William et al., (2020) who define green infrastructure as the use of nature-based solutions to target, treat, and store stormwater at its source, agree that its performance is also highly variable. Due to the aforementioned uncertainties, this can also cause socio-political uncertainty/acceptance and decision-making uncertainty. The WEF Stormwater Report website (2019) notes that green infrastructure often requires more frequent upkeep and maintenance than gray infrastructure, generally entails more financial risk and agrees on the uncertainty of its (green infrastructure’s) effectiveness. However; the same article (2019) does go on to analyze the conclusion, from a joint report between The World Bank and the World Resources Institute, which offers a new perspective on how to increase green infrastructure’s viability: by using it alongside gray infrastructure.
Current State of Georgia’s Stormwater Infrastructure
Atlanta’s SW Status
Counties SW Status
Watershed Status
The state of Georgia addressed the direct stormwater physical and economic impacts on Georgia communities in the GSMM (2016). The manual stated the following as significant impacts:
● Increased Flooding
● Endangerment of Human Life from Floodwaters
● Property and Structural Damage Due to Flooding
● Impairment of Drinking Water Supplies (Surface and Groundwater)
● Increased Cost of Treating Drinking Water
● Loss of Recreational Opportunities
● Declining Property Values of Waterfront Homes and Businesses
● Loss of Sport and Commercial Fisheries
● Closure of Shellfish Harvesting Areas
● Reduced Drought Resiliency
● Increased Litigation
● Reduction in Quality of Life
Future Elaboration of Literature Review:
1. Georgia’s approach to address stormwater concerns
a. Where does GI fit into this?
b. Any Barriers?
2. The current state of Georgia’s stormwater infrastructure. –
3. Attempt to identify any stormwater issues specific to the counties (cobb, dekalb, fulton counties only)
4. Attempt to identify any stormwater issues specific Watersheds (utoy creek, proctor, entrenchment)
5. Benefits & purpose of Green Infrastructure
6. Explanations (purpose, logistics, how it works) of each type of Green Infrastructure installation that will be used for this research (rain barrel cisterns, rain gardens, pocket wetland, dry wells)
7. Guidelines/Information tools that I have found specific to managing Stormwater in Georgia