Help learning about river flow rate

Joined
Mar 28, 2014
Messages
115
Location
Northwest Indiana
Hello,

Now that I am a paddler I take great interest in my closest river system, the Kankakee River. I use the following NWS Hydrograph to keep track of conditions:

http://water.weather.gov/ahps2/hydrograph.php?wfo=lot&gage=slbi3

Could someone define KCFS for me please? It is the unit of measure for flow rate and I am trying to get a feel for how it is used and how the numbers would compare with different conditions (on other rivers). I've seen CFS used also.

Just trying to learn a little bit. I know with time I'll see the conditions and watch the numbers to learn as I go.

thanks for any help,
 
Joined
Nov 29, 2012
Messages
453
Location
southwest Indiana
Hello,

Now that I am a paddler I take great interest in my closest river system, the Kankakee River. I use the following NWS Hydrograph to keep track of conditions:

http://water.weather.gov/ahps2/hydrograph.php?wfo=lot&gage=slbi3

Could someone define KCFS for me please? It is the unit of measure for flow rate and I am trying to get a feel for how it is used and how the numbers would compare with different conditions (on other rivers). I've seen CFS used also.

Just trying to learn a little bit. I know with time I'll see the conditions and watch the numbers to learn as I go.

thanks for any help,

The term cfs refers to cubic feet per second. A cubic foot of water is about 7.5 gallons. Cubic feet per second then refers to the number of cubic feet of water that flows downstream past a defined point on a streambed in one second. One hundred cubic feet per second would be just under 750 gallons per second. The term kcfs refers to thousands of cubic feet per second. So 1 kcfs would mean approx. 7500 gallons flowing past you each second as you sat on the bank watching the river run. Since the flow of the Kankakee is currently 2.1 kcfs, 15,700 gallons of water are flowing past wherever the gauge is sited each second at this moment.

Obviously that sounds like a lot of water but in order to interpret that flow rate you need to know something about the width and depth of the stream bed. 2100 cfs would be an enormous volume for a small creek but would be a tiny trickle for the Colorado River in the Grand Canyon.

Still, a volumetric flow rate is usually much more helpful than a gauge reporting only level in feet and inches. The reported stage of a river in feet depends entirely on where and how the gauge was placed and the info has meaning only if you are familiar with that particular stream. In one case a stage of 2 feet might correspond to a river in flood whereas a stage of 4 feet on a different stream might correspond to a relatively low level.
 
Joined
Mar 28, 2014
Messages
115
Location
Northwest Indiana
Again, thanks. I saw of what you mentioned about the different gauge locations when I checked others up river. When the river makes the news at flood stage, it is the Shelby location that is reported, so I will keep track of it and get a feel for what the river is doing. I'll get an average mph with a GPS when I do a float in the future. The second link was interesting too.
 
Joined
Nov 29, 2012
Messages
453
Location
southwest Indiana
If you repeatedly paddle the same river and keep track of the gauge readings, you will soon develop a good feel for what a given flow rate means in terms of volume and current velocity.

The USGS gauge for the Kankakee at Shelby, IN reports here: http://waterdata.usgs.gov/in/nwis/uv?site_no=05518000

Note that the flow data graph also gives you median flow rates for the same dates in the past. Some USGS gauging sites also provide water temperatures.

In addition to checking the Shelby gauge, it is a good idea to check upstream gauges, particularly during or immediately following periods of heavy rainfall. This will give you an idea not only of what the river is doing at Shelby, but what it is likely to do in the immediate future. In this case there is a USGS gauge at Dunn's Bridge, IN: http://waterdata.usgs.gov/in/nwis/uv?site_no=05517500

Typically, rivers gain volume as the flow downstream gathering tributaries so generally, the flow rates will increase as you look at gauge readings progressively downstream. This may not be true for rivers impounded by dams if the amount of water flowing into the reservoir is less than what is being released at the dam. It may also not be true for rivers in which large volumes of water are being withdrawn for water supplies of large cities or for agriculture. An example is the mighty Colorado River which is sucked dry before it reaches the Gulf of California. Another example is the Delaware River which has such large volumes diverted into reservoirs by New York State to supply drinking water for NYC that there is a potential risk that the brackish water of the Delaware Bay estuary could back up sufficiently to contaminate the water supply for Philadelphia.

In the case of the Kankakee there are no large tributaries between Dunn's Bridge and Shelby and nobody appears to be sucking the river dry, so the flow rate at Shelby (1800 cfs) is only a little greater than at Dunn's Bridge upstream (1400 cfs). If you look at the next gauge downstream at Momence, IL you find that the river has picked up a fair bit of volume (2270 cfs): http://waterdata.usgs.gov/il/nwis/uv?05520500

Note that the stage of the river at Momence is 2.46 feet, the stage at Dunn's Bridge is 5.12 feet but the river has more than half again as much volume flow at Momence as at Dunn's Bridge.

During periods of heavy rain a river will typically rise first at its headwaters. The stream bed is physically smaller there so the stage will typically rise more quickly and much more dramatically than it will further dowstream. By watching the upstream gauge during and following rains and comparing it with the Shelby gauge you will develop a feel for how long it takes for a rise in the river upstream to be reflected at Shelby, and how much precipitation it takes to produce a given rise in the river.
 
G

Guest

Guest
I've found my mini-trip reports to be very useful. Here are a few pertaining to a single stretch of the Sugar River SW of Madison, Wis. The detail enables me to understand in some depth what to expect in any flow conditions. Something that you can't tell from a flow gauge is how the river responds to high flow conditions. This section of the Sugar has very few cutbanks, so high flow doesn't create high water because is spreads out into the surrounding woods. The result is that the current isn't much faster than normal. Other rivers that have deeply cut banks - such as Badfish Creek, whose gauge site I posted above - will rise and can move very fast. E.g., Badfish at normal summer flow - 100-150 cfs - has a current of about 2-3 mph. At 500 cfs it's rockin' and rollin'. So if you want to predict what a river will be like, in addition to the flow data you really have to know the nature of the riverbed.
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8/13/11Sugar RIndependence w/Rutabaga trip led by JeffAttica to Albany 26
4:00 + 0:30 break;
Attica-EE 3:00
T-storms & rain threatened but didn't happen; mostly cloudy, then mostly sunny.
206 cfs, 3.67 ft at Albany (288 cfs, 0.97 ft at Brodhead)
One portage, lots of cluster-gaggles at obstacles.
Kayakers: Jeff (trip leader), Steve, Bob & Barb, Paul & Valerie; canoeists: Steve & Kate
6/14/13Sugar RArielAttica (Hwy C) to EE 27
1:40 nonstop
Sunny, mid-70s, some wind in places. Great flow (450 cfs, 1.6 ft at Brodhead). Bike shuttle via Norwegian Rd. The Ariel handled nicely - very smooth.
6/21/13Sugar RAriel w/Kirk & Gwen (Mohawk) - lessonAttica (Hwy C) to EE 28
2:45 nonstop
Cloudy, mid-70s, post-T-storm. Good flow (380 cfs, 1.3 ft at Brodhead). Car shuttle. Kirk & Gwen were good students - motivated and enthusiastic.
7/5/13Sugar RWildfire (BG) w/Carol in ArielAttica (Hwy C) to EE 29
3:05 nonstop
Sunny, low 80s, light SW wind. High but not too fast (560 cfs, 5.1 ft at Albany, 850 cfs, 2.6 ft at Brodhead). A coaching trip for Carol. She has the usual newbie confusion but seemed to understand back ferrying. She got crossways at a chute 5 min. from the takeout and dumped. She stayed safe so I recovered the Ariel, and she paddled back wet but OK.
7/20/13Sugar RMorningStar w/CarolAttica (Hwy C) to EE 30
1:50 nonstop
Sunny, around 80, light SW wind. Very nice current and higher than normal (300 cfs, 4.0 ft. at Albany; 470 cfs, 1.62 ft at Brodhead). A very enjoyable outing. Carol paddled stern: she started clunky but finished well, occasionally very smooth. Many obstructions were more open or gone, including the one that almost ate the Ariel last time.
9/5/13Sugar RNorthStar w/CarolAttica (Hwy C) to EE 31
1:40 nonstop
Sunny, around 75, wind E 5-10. Good current, slightly higher than normal for this date. (275 cfs, 3.7 ft. at Albany; 305 cfs, 1.12 ft at Brodhead). Carol paddled bow: she started clunky but finished well, occasionally very smooth, anticipating need for sweeps and draws. Many more obstructions were gone.
 
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G

Guest

Guest
If you repeatedly paddle the same river and keep track of the gauge readings, you will soon develop a good feel for what a given flow rate means in terms of volume and current velocity .

Once you are familiar with the gauge/cfs of the river you can make informed decisions about paddling. If there are guide books, or even better local (club) paddlers, to help clue you in beforehand as to what constitutes “canoe zero” for passage and what starts to get hairy those two data points may help keep you from mistakes.

On my local homeriver I’ve got “the feel”, and can glance at the gauge and know what the river will be like based on hundreds of previous trips at levels between 0.8 ft (more gravel bar wading than paddling) and 12 ft (an eddy-less flush, with bridges overwashed and I never want to do that again thanks).

That said, if you begin to range further afield keeping a record of the gauge/cfs is even more important.

For less frequented rivers I’ve begun printing the archived data from the USGS site for the dates that I was on the water, especially for multi-day trips, and making written notations on the print out.

For example, the Green River gauge gives me this for Spring 2014

http://waterdata.usgs.gov/nwis/uv?c...od=&begin_date=2014-04-23&end_date=2014-05-14

And this for the same time period in 2013

http://nwis.waterdata.usgs.gov/usa/...od=&begin_date=2013-05-03&end_date=2013-05-12

That’s a helluva difference, and having campsite and paddling condition notations overwritten on the printed gauge copy brings greater clarity to my sometimes fuzzy recollections.

Same goes for printing a copy of the tide for coastal trips.

http://www.saltwatertides.com/dynamic.dir/marylandsites.html

Select the dates, print it out and overwrite notations regarding the route, depths and tidal flow effects for future reference. Tidal notations, combined with a weather print out for wind speed and direction (annotated for changes) becomes its own education in the combined effect of tide and wind.

Some folks can recall that stuff with clarity years later. Without some written reminder I cannot.
 
Joined
Mar 28, 2014
Messages
115
Location
Northwest Indiana
Thanks to everyone. I want to learn what I can before making my first trips on the Kankakee. Sadly, it is not the case with everyone and the Kankakee claimed a young canoeist's life in the last week. Details I saw were sketchy, but I thought it was easily preventable with some forethought (4 young adults in one canoe near darkness). I feel very bad for all involved and affected.
 
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