By Suzanne Welander
Georgia is home to some of the preeminent paddling experiences in North America. It’s not only that the state is large and has many rivers and waterways. The diversity is breathtaking: crystalline mountain whitewater waterfalls; blackwater streams meandering over white sands; expansive swamp wildernesses; 100 miles of coastal marshes. That the state’s mild climate enables year-round paddling is the icing on the cake. Georgia’s geologic regions, their streams, rainfall, and climate are described in this article. Also included is a primer on water quality issues in the state.
Increasingly, broad coalitions interested in water quality are working together to develop canoe launches and ramps, making it easier than ever to enjoy Georgia’s beautiful creeks, rivers, marshes, and swamps. Georgia has 14 developed water trails, with more to come. Short descriptions are provided in a separate article on Georgia Water Trails.
Georgia’s 3 Geologic Regions
Georgia can be divided roughly into three geologic regions: Mountains (including the Cumberland Plateau, Valley and Ridges, and Blue Ridge Mountains), Piedmont, and Coastal Plain, Geology, topography, and stream channel development varies significantly from region to region, creating distinctly diverse river ecologies and paddling experiences.
Georgia receives an average of about 50 inches of rain per year, most of which comes from warm, moist air masses formed over the Gulf of Mexico. Average rainfall decreases with distance from the Atlantic Ocean and the Gulf up to the Fall Line that separates the Piedmont from the Coastal Plain, North of the Fall Line. average rainfall increases again as air masses are forced to rise and thus precipitate moisture as they pass over the ridges and mountains.
On average, less than half of the water that falls on Georgia finds its way into stream channels. Streamflow has two components; direct runoff from rain and groundwater seepage. As the climate charts below show, the amount of water that actually makes it into rivers is heavily impacted by the seasonal demands of plant transpiration and evaporation. Because the elevation of the land, ability of the soil to retain water, and the type and density of vegetation vary dramatically through the state, the amount of rainfall that translates into streamflow varies more significantly than the actual rainfall levels.
A description of the geologic and hydrologic characteristic of each region follows, along with charts illustrating the typical rainfall, streamflow, and air and water temperatures for the rivers found within each region.
The mountain region contains two distinct regions. The Cumberland Plateau, including the Valley and Ridge Region, is found in the northwest corner of the state; the Blue Ridge Mountains span the north-central to northeast corner.
The Cumberland Plateau and the Valley and Ridge
The Cumberland Plateau region and the valley and Ridge region grade one into the other; the Paleozoic sedimentary rocks of the Cumberland lie almost flat, whereas those of the Valley and Ridge are folded. The latter province, which extends into Tennessee and Alabama, gets its name from the long parallel valleys separated by ridges that resulted from the erosion of the folded rocks that extend into Tennessee and Alabama.
Erosion works fastest on the limestone that underlies most of the valleys. Not only is the limestone broken up by other rocks carried by moving water, but it is also dissolved by the water itself. This erosive action has carved an extensive network of interconnected subterranean channels and caverns. Through these large openings, the water moves as freely as it would through a city water main. Since the underground channels are connected under large areas, water that falls as rain in Tennessee may flow underground and emerge in Georgia, or water that falls in Georgia may surface in Alabama. In the Valley and Ridge region, many streams are sustained during dry weather by the numerous springs that are characteristic of the region.
Both regions are drained by a network of streams that carry substantial river flow. Those in the northwestern part of the state drain north into the Tennessee basin; the remainder drain southwest into the Mobile basin. The streams generally flow in deep channels meandering through wide floodplains. Where they cut through the ridges in water gaps, they are shallow and swift and have numerous rapids under-girded by jagged limestone rocks. Steep slopes give rise to rapid runoff, and flash flooding is common.
The Blue Ridge
The Appalachian Mountains of the eastern United States extend southwestward from the state of Maine to the Blue Ridge province of Georgia. The Blue Ridge Mountain region contains thousands of acres of forest, mountains, and rivers. The area is not farmed extensively nor is it densely populated. The steepness of the topography makes the land more suitable for forest than for farms.
The region is drained by the headwaters of four basins: the Tennessee, Savannah, Chattahoochee, and Coosa. The rivers within the region are small and have small drainages, but they have the highest flow for their size in the state. Their channels are steep and rocky, and water flows swiftly over an abundance of rapids and falls.
The Blue Ridge Mountain region is underlain by rocks that the geologists refer to as crystalline, which includes granite, slate, gneiss, and other dense, hard rocks. The mountains are high and steep and have nearly V-shaped valleys covered with luxurious forests and thick soil, which retard runoff.
The Blue Ridge Mountains are the coolest and wettest part of the state. Average annual rainfall in the region ranges from 55 to more than 80 inches per year, with the greatest amount falling in higher altitudes. The average annual temperature is about 58°F, 10 degrees cooler than that in southern Georgia.
The graphic below illustrates the average rainfall and streamflow by time of year for those streams in the mountain region (mostly the Blue Ridge Mountain streams). The y-axis delineates precipitation in inches; the x-axis marks time of year. Streamflows are expressed as a percentage of the annual average (which equals 100%). Plotted values are the medians of 20 years (1995-2014) daily mean streamflows averaged across 19 gauges located on rivers in Georgia’s Mountains region. Rainfall values are the medians of 30 years (1981-2010) daily precipitation observations averaged across 22 NOAA weather stations in Georgia’s Mountains region.
The next table illustrates the high and low air temperatures and average water temperatures for the streams found in the mountains. Water temperatures are the average daily mean temperatures gathered from the USGS stream monitoring stations associated with the portion of this book’s rivers located in Georgia’s Mountains region, where available. Air temperatures are the author’s summarization of climate norms data provided by NOAA. These plotted values are the medians of 30 years’ (1981-2010) daily temperature observations averaged across 16 weather stations located in Georgia’s Mountains region.
The Piedmont Region, found directly south of the mountains, is underlain by the same crystalline rocks as the Blue Ridge Mountains but lacks the mountains’ heights. Instead, it is an area of rolling plains broken occasionally by narrow stream valleys and prominent hills. The soil cover in the Piedmont is not as thick or as capable of slowing runoff as that of the Blue Ridge.
The region includes parts of several drainages. The Savannah, Ogeechee, Ocmulgee, and Oconee Rivers drain into the Atlantic Ocean while the Flint and Chattahoochee drain into the Gulf of Mexico. Throughout most of the region, the main streams flow southeastward, with the general slope of the upland, and cross the underlying rock structure at right angles. This creates shelflike rapids that stretch from bank to bank and rivers that don’t run through well-defined channels in comparatively narrow valleys, in contrast to rivers like the Chattahoochee. In the northwestern section of the Piedmont, the Chattahoochee and some streams in the Mobile basin tend to parallel the direction of the rock strata. Rivers there generally have moderate slopes interrupted by occasional rapids and falls and flow in well-defined channels within comparatively narrow valleys.
Ridges between the major drainage systems of the Piedmont are broad and rather sinuous, with the region’s primary cities. highways. industries, railroads, and farmlands concentrated atop of them. Towns were first established on the ridges along the old wagon trails and railroads because the ridges were well-drained routes that required a minimum number of bridges and were free from the danger of floods.
Rainfall along the northern Piedmont, the area of highest elevation. averages more than 50 inches annually. To the south and east, the rainfall is less. The Augusta area receives less than any other part of the state, a little more than 42 inches annually.
The table above illustrates the average rainfall and streamflow in the Piedmont by time of year. Plotted values are the medians of 20 years’ (1995-2014) daily mean streamflows averaged across 32 gauges located on rivers in Georgia’s Piedmont region. Rainfall values are the medians of 30 years (1981-2010) daily precipitation observations averaged across 48 NOAA weather stations in Georgia’s Piedmont region.
The table below shows the average high and low air temperatures, along with the average water temperature for the Piedmont’s streams. Air temperatures are the author’s summarization of climate norms data provided by NOAA. These plotted values are the medians of 30 years’ (1981-2010) daily temperature observations averaged across 41 weather stations located in Georgia’s Piedmont region.
Water temperatures are the average daily mean temperatures gathered from the USGS stream monitoring stations associated with the portion of this book’s rivers located in Georgia’s Piedmont region, where available.
The Savannah and Chattahoochee Rivers were not included in the calculation of average water temperature. During the warm months, both rivers are 10-20 degrees colder than other Piedmont streams due to cold-water releases from their power-generating dams.
COASTAL PLAIN REGION
The Coastal Plain begins immediately south of the Piedmont at the Fall Line – a discernible geologic break between the hard rock strata of the Piedmont and the more easily eroded rock of the Coastal Plain. This line, which roughly parallels the eastern seaboard, is marked by steep cliffs, rapids, and waterfalls.
Cretaceous sand aquifers, a blanket of sand and gravel, begin at the Fall Line and thicken to the south. Rainfall filters into this sand blanket and recharges the sand aquifer with water. When stream levels are high, water moves from the streams into the sands. When the stream levels are low, water feeds back from the sands into the streams.
Streams crossing the Coastal Plain that originate in the Piedmont or in the Blue Ridge transport heavy loads of sediment. The Savannah. Altamaha, Ogeechee, Alabama. and Apalachicola (including the Flint and Chattahoochee) systems carry large sediment loads and are therefore considered alluvial rivers.
The streams that originate in the Coastal Plain generally carry very little sediment. Running over sand and sandy clay, their waters flow clear and sparkling. colored a reddish tea color by tannic acid derived from tree roots and decaying vegetation. Because the reddish water appears glossy and black in direct sunlight, these streams are known as blackwater rivers.
In the southwestern area of the upper Coastal Plain near Albany, limestone-sand aquifers give rise to lime sinks, caves, underground rivers, and artesian wells. These features are formed by the solvent action of water on limestone. When the limestone is dissolved, caverns and interconnected channels are left below the surface. If the cavern roof collapses, sinkholes are created. In low water periods, sinkholes can consume the entire flow of these southern rivers, creating a dead end for paddlers.
The annual rainfall in the Coastal Plain averages 45-52 inches, draining slowly over the flat terrain, with the part that does not sink into the ground quickly evaporated or consumed by vegetation. The table below illustrates the average rainfall and streamflow for the streams of the Coastal Plain. Plotted values are the medians of 20 years (1995-2014) daily mean streamflows averaged across 32 gauges located on rivers in Georgia’s Coastal Plain region. Rainfall values are the medians of 30 years’ (1981-2010) daily precipitation observations averaged across 53 NOAA weather stations in Georgia’s Coastal Plain region.
Hydrologists differentiate between streams in the upper Coastal Plain and the lower Coastal Plain. Streams in the upper Coastal Plain have relatively uniform flows and high volume because of minimal storm runoff and large groundwater inflow. The average annual runoff of the larger streams ranges from 12 to 28 inches. The streams are generally sluggish and flow in deep, meandering, low-banked, tree-choked channels bordered by wide, swampy, densely wooded valleys. The very small streams commonly have very little runoff because the permeable soil absorbs rainwater rapidly and the channels are not entrenched deeply enough to intercept much groundwater flow.
The lower Coastal Plain generally has the least runoff of any part of Georgia, averaging 9-14 inches annually. Streams here wander in wide, swampy, heavily wooded valleys separated by very wide and very low flat ridges. Swamp vegetation consumes large quantities of water and evaporation loss is high.
The Coastal Plain is the warmest region of the state; seasonal temperature averages are shown in the table above. Air temperatures are the author’s summarization of climate norms data provided by NOAA. These plotted values are the medians of 30 years (1981-2010) daily temperature observations averaged across 63 weather stations located in Georgia’s Coastal Plain region. Water temperatures are the average daily mean temperatures gathered from the USGS stream monitoring stations associated with the portion of this book’s rivers located in Georgia’s Coastal Plain region, where available.
Georgia’s Water Quality
How clean are the state’s waters? Development. industry, drinking water, power generation, recreation: As the population increases, conflicts over water usage – and pollution – rise. The ecological health of a waterway affects the quality of a paddler’s experience in several ways, from increased risks to boaters who take an inadvertent swim to decreased wildlife and vegetation en route. Paddlers are an important constituency when it comes to understanding the sources of pollution and what’s being done about it. Provided in this section are a very brief primer on pollution, the regulations that protect water quality in Georgia, resources, and information on where boaters can turn to find out how affected a particular waterway is.
THREATS TO GEORGIA WATERWAYS
- Population increases that drive commercial and residential development near rivers, thereby reducing the land’s natural ability to filter pollution out of water draining into streams.
- Sedimentation due to erosion, which creates a hostile environment for aquatic life by depriving it of vision and respiration and decimating fish’s spawning grounds.
- The absence of natural vegetation that holds stream banks in place and provides the cool shady places fish need to rest and spawn.
- Effluent from poultry and hog farms, which kills aquatic species by creating algae blooms that rob streams of oxygen.
- Chlorine and stench from sewage-treatment plants.
- Harmful bacteria and protozoa from untreated sewage that overwhelms treatment facilities during rainstorms.
- Runoff, referred to as “non-point-source pollution,” which flows into streams from streets, lawns, parking lots, and other areas of human and avian activity.
- Toxins that accumulate in fish, harming anglers who eat their catch.
- “Point-source pollution,” that is municipal and industrial discharge, some of which is permitted by the state Environmental Protection Division (EPD).
- Household trash and roadside litter.
- Invasive species, such as Chinese privet, that out-compete native plant species for sunlight, water, and soil and disrupt habitat that supports other native species.
To find out how polluted a river, stream, reservoir, or stretch of coastal waters is, visit The Environmental Protection Division website Georgia 305(b)/303(d) List Documents. The Georgia Environmental Protection Division provides this information in accordance with the Federal Clean Water Act.
Because of their on-the-water view of what’s happening on Georgia’s streams, paddlers may be the first to notice issues that need to be addressed. When sedimentation or other pollution violations motivate you to take action, first take photos without trespassing on private land. Note the exact location of the violation. GIS location data on the offending property will help determine jurisdiction. Violations can be reported to one or more of these sources:
LOCAL RIVER PROTECTION GROUPS If there is a local watershed association, that’s the easiest way to report a violation. Find out if the impacted waterway has a watershed protection organization through the Georgia River Network’s website Discover a Local River Group.
The Chattahoochee Riverkeeper website has an online form that can be used for reporting erosion, sedimentation, or pollution violations in counties contiguous with the Chattahoochee River as far south as West Point Lake.
CITY OF ATLANTA Helpful because of the concentration of development activity; erosion concerns can be called in to 404-546-1300.
GEORGIA DEPARTMENT OF NATURAL RESOURCES (DNR) Serious pollution violations such as fish kills and major spills should be reported directly to the state via their 24/7 emergency hotline at 800-24I-4113.
When there is no watershed association protecting a river, use the state’s DNR hotline to report violations. Knowing the exact location of the observed violation will help determine the proper authority for follow-up. Enforcement is expected to take place at the county level; half the time, city enforcement takes precedence. Not all counties are well equipped to address complaints. Water and soil conservation commissions can also come into play. Thankfully, the state will figure out who the responsible party is.
Tools to Combat Water Pollution
Laws that govern river protection are the most important tools for limiting abusive treatment of water and the land surrounding it.
STATE LAW Georgia’s stream buffer laws require all streams having year-round flow, even where crossing private property, to have a buffer of natural vegetation on both sides of the stream at least 25 feet wide. A stricter standard applies to primary trout streams, where the minimum buffer width is 50 feet. The law prohibits any land-disturbing activity within the buffer zone, except that which is temporary and for which best management practices are used to minimize erosion.
The law establishes a benchmark for river protection in the state. Yet, paddlers still witness a continuing creep of single-family residences whose land use violates the buffer zone, whose denuded yards and banks are not allowed to grow vegetation capable of maintaining healthy stream banks. The lack of compliance indicates that the law is poorly understood and frequently unenforced with respect to residential dwellings.
Putting teeth into the law behind enforcement, in 2003, the state legislature appropriated resources for the Environmental Protection Division (EPD) to hire inspectors who verify that large construction sites control soil erosion. Inspectors levy stop-work orders that shut down noncompliant job sites until they clean up their act. State laws also now require developers to have employees trained and certified in best-management practices on site while land-disturbing work is performed.
The most well-written laws can fall short in practice. Exploiting an apparent loophole, in 2014, the Georgia EPD published a ruling stating that they would no longer enforce the buffer protection law in coastal marshes. Though the courts overturned the ruling, the EPD restated their interpretation and is appealing. Conservation groups are pursuing legislative clarification of the law to reinstate and ensure continuing protection of these delicate ecosystems.
FEDERAL LAW In cases where municipal, county and state governments have failed to protect streams. federal law in the form of the Clean Water Act has given Georgia citizens the leverage needed to bring polluters into compliance with the law, and to penalize polluters for past violations. It has also been used with success to force the state EPD and the national EPA to enforce specific laws protecting streams when those agencies lacked the resources or will to do so on their own initiative.
Other significant tools for impacting river health include the following:
GREENWAYS Local governments, aided by private organizations and individual donors, raise money to purchase land surrounding waterways, which is then maintained as green space. By establishing such greenways, these communities protect waterways from reckless development and enhance the quality of life in their neighborhoods. The rapid development of parks and hiking, paddling, and biking trails near Georgia rivers is impressive; what’s more impressive is to see them well used and loved by the people who live nearby.
EDUCATION Less conspicuous outside of agricultural and industrial circles but nevertheless critical to our environment, county extension agencies, along with the Georgia Soil and Water Conservation Commission, educate farmers and land developers in conservation and best-management practices and can help secure grants and loans to help farms mitigate their impact on streams.
LOCAL INTEREST Citizens living in each of Georgia’s major watersheds have formed groups, often calling themselves “watershed alliances” that endeavor to protect the health of their respective local streams. These alliances provide an umbrella for uniting diverse stakeholders in a river’s health. Some of these organizations go on to become Riverkeeper organizations that hew to quality standards set by the national Waterkeeper Alliance.
Organizations and Resources for More Information
Georgia is home to many caring people who fight to keep local streams clean. They work with guidance and coordination from an increasing number of organizations focused on river protection. The success of their continuous efforts makes it very clear that when citizens get involved they have the power to turn the tide against water pollution. These organizations educate, bring more caring voters to the table, monitor adherence to laws, and take legal action when discussion fails.
THE GEORGIA RIVER NETWORK (GRN) GRN is building broad interest in healthy waterways from the mountains to the coast. They provided the leadership that catalyzed the state’s rapidly growing water trail system, notable for inspiring communities to create coalitions to protect their local rivers. GRN hosts the weeklong annual Paddle Georgia journey on a different Georgia waterway each year and hosts trips of shorter duration on different rivers. The GRN website is packed with information on river protection including how to create a river protection group, a water trail toolkit. and grant opportunities.
RIVERKEEPERS AND WATERSHED AlLIANCES These local groups are focused on a single watershed. More than 30 waterways have dedicated watershed alliances. Some reservoirs have them, too. The largest in the state, Chattahoochee Riverkeeper continues to write the book on standing up to government and special interests to champion the rights of Chattahoochee watershed residents to have clean, healthy waterways. Behind the scenes of their more visible heroics, a dedicated staff does the yeoman’s work of monitoring streams, formulating public policy based on the best available science, taking polluters to court, and educating schoolchildren – training them to serve as the environmental stewards of our next generation.
GEORGIA WATER COALITION This is the umbrella organization for water quality issues in the state. More than 200 organizations are members of the coalition, which actively seeks organizations of any size to sign on. The organization produces a “Dirty Dozen” report every two years outlining its recommendations for water management in Georgia and provides support to help citizens get involved with regional water planning, quality, and legislation.
THE GEORGIA CONSERVANCY The Georgia Conservancy is involved in a wide range of environmental conservation causes and is a leader in guiding the development of Georgia’s stream protection laws. Their website is an excellent resource for learning about these issues.
ENVIRONMENT GEORGIA This citizen-based advocacy organization is part of a nationwide federation of state-based organizations. This lean and focused organization rolls up their sleeves to do the painstaking work of stitching together constituencies around conservation issues, and confidently represents conservation interests to elected officials when decisions are being made.
THE SOUTHERN ENVIRONMENTAL LAW CENTER (SELC) puts the power of the law to work to protect Georgia’s natural resources. The Center chooses projects that set precedence, strengthen far-reaching policies, or protect places too special to lose. Visit the website to find out what priorities SELC is currently focused on in Georgia.
AMERICAN WHITEWATER This national nonprofit organization works to conserve and restore America’s whitewater resources. in addition to enhancing opportunities to enjoy them safely.
“Why Georgia is Home to Some of the Preeminent Paddling Experiences in North America” is adapted from Canoeing and Kayaking Georgia by Suzanne Welander and Bob Sehlinger and published here in cooperation with Menasha Ridge Press. Canoeing and Kayaking Georgia covers thousands of miles of Georgia waterways from whitewater to wilderness swamps and everything in between. It’s an indispensable guide to anyone interested in paddling Georgia’s rivers and streams. Order directly from Menasha Ridge Press. See a comprehensive list of other Menasha outdoor publications indexed by title, author, category, and region.