Before you grab your paddle and hit the water, there’s one question you should always ask: Is the river at a good level today? The answer is not always simple. A good level for stretches of the Upper Cahaba within Birmingham will not apply to stretches of the Lower Cahaba in Centreville. Water levels also vary from paddler to paddler; some paddlers prefer high, fast moving water and some prefer a slower, more relaxing experience. Here you will find information on who measures stream data, how it is measured, where you can find that data, and how it applies to the Cahaba River.

Who Measures Water Level and How?

The United States Geological Survey (USGS) has measured stream data for over 100 years. Beginning in 1889, USGS installed probes in rivers across the United States. If you’ve ever noticed a silver box on the side of a bridge as you’re crossing a river, it’s very likely connected to a USGS probe. These probes collect various information such as gage height, discharge, dissolved oxygen, temperature, and pH. As paddlers, this data is extremely helpful in determining whether you can, or should, “run” a river.

You can access all of this data on the the USGS National Water Dashboard. This interactive map shows all of the active gages across the US. Zoom in to find the Cahaba River and the stretch of river you’re interested in paddling. There is a color-coding system that indicates whether the current conditions are low, normal, or high based on historic data.

Some paddlers look at “gage height” as an indicator of the river’s current conditions. We at CRS prefer to use “discharge”. Discharge is a volumetric measurement of the amount of water passing the USGS probe at a specific point in time. It is measured in cubic feet per second (cfs).

What is a Safe Water Level for My Trip?

Now that you know where to find the discharge of a river, what’s next? Now you can refer to the Cahaba Blueway, an online trip planning tool designed to be your one-stop-shop for all Cahaba River trip planning needs. Select “Blueway Map” to zoom in on different access points and other points of interest.

Navigate around the map until you find the boat access that you are wanting to start your trip from. Remember: rivers flow downstream. You always want to check the upstream gage. It will do you little good to know how much water is flowing through Marion when you’re paddling in Hoover. Through the Blueway access points, you will find helpful information for your trip including landmarks to watch out for, potential historically and culturally significant locations, potential hazards, and, of course, recommended water levels. (Not every access point on the Blueway map has water level recommendations.)

Getting on the River

Now that you have the current stream conditions from USGS and the recommendations from the Blueway, you are ready to make a decision regarding whether or not you want to run that stretch of the Cahaba. As you paddle more of the river, and paddle the same stretches again and again, you will begin to build a sense of what water levels work best for you. Maybe you would like the water to be a little lower for a slow fishing trip or a fun picnic on a rockbar that only shows up when the river is lower. Maybe you would like a bit more excitement, so you prefer to paddle at higher water.

You should always know the hazards of the river and be prepared with the appropriate first aid and swiftwater rescue equipment and training. If you’re uncertain of a stretch of river, contact Wil Rainer for more information. If you’re new to paddling, come on a trip with CRS to learn from the pros in a safe and relaxing environment.

Tags: Cahaba, paddling, safe, water levels