Coastal Georgia Region Technical Information

In support of the Regional Plan Update, separate technical memoranda were developed on water and wastewater forecasting.

Water and Wastewater Forecasting

Water and wastewater demand forecasts form the foundation for water planning in the Coastal Georgia Region and serve as the basis for the selection of water management practices. Forecasts are summarized within Section 4 of the Regional Water Plan, but additional detail can be found in the Water and Wastewater Forecasting Technical Memorandum.

Over the next 40 years, the population in the Coastal Georgia Region is projected to grow by 20%, increasing the demands for surface water and groundwater and increasing the quantity of wastewater generated. Total water withdrawals by municipal, industrial, agricultural, and energy sectors are projected to increase by 13% (32 million gallons per day (MGD)) from 2020 to 2060. Total wastewater flows are projected to increase by 19% (34 MGD) over the same period. 

Upon review of the municipal water demand forecast, the Council decided that it would be 
appropriate to: 

  1. Use the available OPB 2020 population projections in lieu of the OPB 2019 projections 
  2. Use a regional average of 113 gpcd value for the public supplied forecast for each county 
  3. Shift the service area populations for residences served by Water Utility Management from self-supplied to publicly-supplied in each county 

Thus, the municipal water demand forecast presented in the 2023 Coastal Georgia Regional Plan Update is different from the forecast shown in the Coastal Georgia Water and Wastewater Forecasting Technical Memorandum. The change in population from the OPB 2019 series to the OPB 2020 series also applies to the municipal wastewater forecast. 

Coastal GA 2060 Water Demand

Resource Challenges

The Regional Water Plan compares the water and wastewater demand forecasts to the available resources to determine potential resource challenges the Region could face. This material is also summarized within Section 3 and 5 of the Regional Water Plan. Areas where future demands exceed the estimated capacity of the source have a potential challenge that may be addressed through water management practices. Potential water resource issues identified for the Coastal Georgia Region include:

  • At the regional level, for modeled portions of the prioritized aquifers, there is sufficient groundwater to meet forecasted needs over the planning horizon; however, meeting the increase in demands in areas where groundwater supplies may be limited due to salt water intrusion is a significant challenge.
  • Over the planning horizon, forecasted surface water demands within the region are not predicted to exceed the available resource.
  • Water quality conditions indicate the potential need for improved wastewater treatment within the Ogeechee, Altamaha, and St. Marys River basins.
  • Addressing non-point sources of pollution and existing water quality impairments should be a part of addressing the region’s future needs.