Al Donaldson

For river and creek paddlers in the US, correct interpretation of river gage readings can be a powerful tool in planning paddling trips.  However, it is necessary for the paddler to know just what information the gages can and cannot deliver.

What the gages are

Modern river gages come in several types, but all of those types are intended to fulfill a single primary function.  A gage measures the level of water in a stream at a specific location.

Most of the gages in the US are principally maintained by either the U S Army Corps of Engineers (USACE) or the US Geological Survey (USGS.)

The data from these gages may be found on the Web at:

USGS Gages (general):  http://waterdata.usgs.gov/usa/nwis/rt

USGS Gages (Iowa): http://waterdata.usgs.gov/ia/nwis/current?type=flow

USACE Gages:  http://www2.mvr.usace.army.mil/WaterControl/new/layout.cfm

What they measure:  gage height

River gages measure one particular characteristic:  the actual height of the water surface at the gaging location.   To interpret this information, it is important for the user to know just what is being measured.

Each river gage measures the surface height of the water compared to a specific altitude above a known sea level reference.  The readings that are recorded by a given gage refer to the height of the water above that altitude (NOT the depth of the river!)

Example 1)

The datum (zero point) for the Black Hawk Creek gage in Hudson, Iowa is given as  865.03 feet above   NGVD29 (National Geodetic Vertical Datum of 1929).  When the creek gage shows a reading of 11.30 feet, this reading means that the actual surface of the water is located at an altitude of (865.03 + 11.30) 867.33 feet above that sea level reference point.  Doesn't sound too useful, does it?  Hang in there, it will become more clear (I hope!)

Example 2)

The datum (zero point) for the Cedar River gage in Waterloo, Iowa is given as: 824.14 feet above   NGVD29. (National Geodetic Vertical Datum of 1929).  When the river gage shows a reading of 7.96 feet, this reading means that the actual surface of the water is located at an altitude of (824.14 + 7.96) 832.10 feet above that sea level reference point.

Interpreting the gage height readings

At this point, all that the gage readings tell us (the above readings were taken at the same time on the same date, by the way) is that the water surface height on Black Hawk Creek at Hudson was 44.23 feet above the level of the surface of the Cedar River at the Waterloo gage.  Not much usefulness there.  So how can these numbers be used?

For paddlers, a gage height reading can be used only as a reference:  it may be compared to earlier readings of the same gage to reveal information about the general "paddleworthiness" of the stream.  For example, if I had made a trip on Black Hawk Creek earlier in the year at a gage reading of 12.00 feet at Hudson, finding the creek to be flowing out of its banks, and had made a trip at a gage reading of 6.25 and found the stream to be too shallow to paddle without walking the boat, then:

 The reading given in Example 1 (11.30 feet) would indicate that I'd surely have enough water to paddle, and would expect the creek to be quite high and to have relatively fast current:  probably not a good trip for inexperienced paddlers (12.00 feet on the creek is considered flood stage.)

If I were to consider a trip when the gage was reading 7.50 feet, I would expect reasonable current and adequate water to eliminate dragging.

However, using gage heights for paddling references can be misleading if the readings that are being used for reference are a bit old:  if the river channel contour near the gage changes over a year's time (or more,) the gage height can be an inaccurate guide to the amount of water flowing in the stream at other locations.  Because of this factor, it is often better to use another value (when available), called "discharge" to evaluate paddling conditions.

Stream discharge

Discharge is a calculated value, based on measured gage height, stream velocity and stream cross section at or near the gage location.  The process of establishing a mathematical relationship between gage height and discharge is beyond the scope of this discussion,but, fortunately, we do not have to do that work ourselves.  Most gaging stations have already had that work done, and for those gages, each gage height has a discharge value in cubic feet per second (CFS) associated with it.  Both values (Gage Height and Discharge) are given on the gage pages on the Web.

Useless, but dull, information

For those of you who are curious about this sort of relationship, 200 CFS is equivalent to 129,254,400 gallons per day.

Example 3)

Example 4)

Interpreting CFS (discharge) readings

Just as with gage height readings, CFS numbers may be compared meaningfully only with CFS readings from the same gaging station from earlier paddling experience.  200 cfs flowing down Black Hawk Creek will allow for a "drag free" trip, if a bit of a slow one;  200 cfs flowing in the Cedar River at Waterloo would just be a damp spot in the middle of a big mud plain!

On the other hand, 10,000 cfs flowing down the Cedar River is just high water:  the same amount flowing in a small creek would be a 10,000 year flood.  The appropriate amount of water for paddling depends on the stream's size and the terrain through which it flows.

Just as with gage heights, discharge numbers may be used to compare current conditions with earlier observations!

Actual usage

For each of my stream trips, I keep a log of trip date, location, gage readings and paddling conditions (too low, too high, etc.)   This log allows me to check the real-time discharge numbers with those of previous trips.  For streams that I have not paddled, I try to contact some other paddler who has such information for that stream.

***Cautions***

Short term problems

Gages can go out of calibration and stream channel contours can change at the gaging station.  These happenings can cause misleading numbers to show up on the gage pages.  When the gages are calibrated and discharge formulas checked, there will appear a red asterisk on the chart of the station on the web page.  (See Examples 1) and 3) above.)  If such marks are showing on the gage charts, then the gage numbers are probably accurate.

Long term problems

Streams change over time, especially in Iowa, where our agricultural practices have caused us to allow more surface water and topsoil to enter the streams each year.  Most of our rivers and creek channels are becoming wider (sometimes many feet wider each year.)  This channel widening makes for much shallower conditions at a given flow at any spot where the channel is wider than before.  Any discharge logs of four years of age and over are suspect.

Interpretation problems

Paddlers all have different likes and different boats need different water characteristics.  An individual who uses paddle craft primarily for fishing may well like a water level that would frustrate a paddler who likes to paddle many miles a day.  A hundred pound paddler in a long day-tripping kayak can paddle easily in water depth that would completely stall out two people with a week's worth of camping gear in a 16' tandem canoe.

If you use somebody else's recommendations, be sure that you know when, what and how that person paddles.

Hope this is helpful.

2011/05/29

Lake Red Rock Full Moon Paddle

Ask local paddlers about  how they got started paddling and many will cite the fun they had while participating in a Full Moon Paddle ("FMP").  These events have been held on rivers and lakes all over the area, but perhaps the best known FMPs were held at Red Rock Lake.  Some months the trips involved flotillas of over 20 boats, others as few as 3.  Although many of these events occurred during the summer months, some involved cold weather paddling, including one cold February night that was acknowledged on local TV.  And now, plans are being made to revive this great central Iowa tradition.  [The CIP Full Moon Paddle is tentatively planned for August 13th this year--stay tuned for further details]

On these trips, friendships were forged, skills learned, and paddling trips planned.  The FMPs sometimes  started with a pre-dinner get together in Knoxville, or finished with an overnight camp at West Beach.  As just one of many participants in these paddling parties, I have a treasure trove of memories that will long serve as a source of amusement and fun for me (click here for my short list of examples).

If these events were so fun, why did they end?  The simple answer is time and people.  FMPs do not create themselves.  Inspired paddlers like Scott Evans expended time and effort to make these events happen.  As the size of the groups expanded, the logistics grew more vexing: how can that many people put in at one small boat ramp; how can a big group of boats stay together, and finish together?  Further, a growing unease among experienced paddlers started as inexperienced paddlers began to be a safety concern.  In some cases, people arrived with inadequate boats and equipment, and in some cases ended up getting lost or needing a tow.   In other cases, the events were assumed to be nothing more than a water based party, leading to inappropriate and unsafe conduct among people who others didn't know.  Eventually even the DNR became concerned because so many crafts were paddling Red Rock without any lights.  This ultimately led to an unfortunate confrontation where the DNR issued tickets to several paddlers who didn't have adequate illumination on their boats.

TIPS AND SUGGESTIONS  So now, as we look to re-introduce FMPs in central Iowa, we hope that these events will run smoother when paddlers better understand the expectations and requirements.  Below are some thoughts and guidelines to consider if you are interested in participating in a FMP.

1.  YOU ARE RESPONSIBLE FOR YOUR ACTIONS  These events are not sponsored by any organization, for profit or otherwise; they are just a gathering of people with a passion for paddling.  No one is supplying boats, gear or rescue services.  In one case, a person showed up at a FMP with an expectation of meeting guys;  it would have helped if she had shown up with a boat instead!  It is likely that the FMP trips will involve signing of a waiver.  It's important to read it and understand it.  If part of the disclaimer causes you concern, that may be a good reason to ask yourself if you're ready for the event. 

2.  STAY WITH THE GROUP  It may seem hypocritical to say that you're responsible for yourself, and then expect you to stay with the herd.  But good safety practice and water etiquette make this an imperative.  The  skilled boaters are naturally inclined to keep an eye out for the less experienced paddlers.  If the boats are spread out all over the lake, and especially one group cuts out to ply its own path, it becomes difficult for people to know if others are safe.  We want these events to be fun and safe.  Keeping the group together goes a long way towards accomplishing both! 

3.  KNOW YOUR BOAT AND KNOW YOURSELF  Learning to paddle by bringing your new short inflatable kayak to a FMP is probably not a wise move.  Most FMPs will likely be in lakes.  That means there is both the potential for  large waves and paddling in the dark.  If you're not sure about whether you can safely participate with your boat and level of skill, contact someone with the CIP.  We all want to make sure newer paddlers are welcomed and encouraged.  But we equally want to make sure they are safe.

4.  GEAR UP FOR THE CONDITIONS  On my first trip to the Apostle Islands, I recall watching the others put on their wet suits, even though the day seemed warm.  Purely out of peer pressure, I donned mine.  During the crossing to Sand Island, we ran into a squall that extended our paddle and left us scattered all over the beach.  If I had not been wearing a wetsuit I guarantee you I would have had hypothermia.  My point is that gear is a key to comfort and safety.  Decisions about clothing, spare paddles, paddle floats and spare dry bags can be daunting to the newer paddler.  There are a number of articles in the CIP Newsletter archives with ideas about gear and dressing for the conditions.  And, ask around; get some tips; be safe.

5.  LIGHT IT OR CITE IT (my attempt at the nautical version of "click it or ticket")  A full moon paddle means that at least part of the trip will involve paddling after sunset.  There are strict requirements about lights for your boat, and the DNR has proven they are willing to ticket those who fail to comply.  In essence, you need to have a 360 degree light (most of us use some variety of stern lantern), and some kind of direct beam light that can signal a boat as far as a half mile away (most use a headlamp).

Proper Lighting for Lake Red Rock

Truly, some of my best paddling memories are of FMPs in Iowa.  We are all hoping this grand tradition will return and be successful.  But we need the participants help us to make this a success.  If you have any questions, contact me (sbparrish@q.com) or other CIP members. 

Ben Petty

Stream fishing from canoe or kayak can be a great addition to your paddling activities.  Using a canoe or kayak can get you on waters that are too deep or difficult to wade, but my also be too shallow to receive heavy fishing pressure from larger boats. There are a surprising number of small rivers and streams across Iowa that contain healthy populations of smallmouth bass.  Although many of the better-known smallmouth bass streams are in northeast Iowa, any Iowa river with a significant amount of rocky habitat and relatively clean water is likely to contain smallmouth bass.

For technique, during the summer, smallmouth bass will often be found in deeper pools, especially those associated near rocky riffle areas.  Mid-stream boulders, log jams, or other structures that deflect current, along with deep banks associated with rock walls, are all good smallmouth habitat to focus upon.  A good technique while paddling is to float very slowly along the opposite (shallower) side, and cast to the deeper holes and banks.  In clearer streams, getting out above pools or other good structure and walking around to fish those areas is a good technique, as you're less likely to spook fish when doing so.

Peter Komendowski

For lure selection, primary food sources for smallmouth bass during the summer are minnows and crayfish, so lures that mimic these foods should be productive.  Some of the most common lures I use to do so are jig & twistertail (3-4") combinations, shallow diving crankbaits (minnow and crafish imitation), and inline spinners, such as Mepps or Roostertails.

Some of my favorite smallmouth bass rivers to float include sections of the Upper Iowa, Volga, and Turkey Rivers in northeast Iowa, the Iowa River between Alden and Steamboat Rock, and the Des Moines River north of Fort Dodge.  There are also smaller, rocky creeks throughout much of the state that offer good fishing opportunities for adventurous paddlers.  One benefit of the larger streams mentioned is that they often provide multi-species opportunities, including walleye, northern pike, and (in some northeast Iowa rivers) trout.  If you're used to paddling but not fishing, you'll want to shorten the length of your trips.  On waters with good habitat, it is easy to turn a 6 - 7 mile trip into a fishing expedition that will take most of the day.  It is also important to note that smallmouth bass are not stocked in Iowa streams - they are self-sustaining, so please consider catch and release fishing.

Todd Robertson

For those in search of the perfect urban lake paddle will find peace, solitude, wildlife and plenty of area to poke about on Blue Heron Lake. Located in Raccoon River Park in West Des Moines, this former sandpit of the old Penn Dixie cement plant is an ideal location for a quick and easy get-a-way for metro paddlers, anglers and bird watchers. For the metro area, it is the crown jewel of lake combined with park features. The lake is really just an extension of the Raccoon River, which is located just a few hundred feet off the south side of the lake. Anglers will find pan fish, Bluegill, Catfish, Bass and much more. The lake is also home to an extra large Gar fish that we affectionately refer to as "ole Nessie", which over the last few years has received mythical status as only a few have laid eyes on it. Something to watch out for and maybe even grab a few pictures!  

Birders will be in bliss over the variety of bird life, including small groups of migratory species that use the lake as a fast pit-stop while in transit. American Pelican, Osprey, Belted Kingfishers, Warblers and Flycatchers and of course, Blue Herons can all be found on the lake at different times of the year. There is a 3.2 mile trail around the lake for walking, running or biking and on the south side of the lake, the trail runs between the lake and the Raccoon river, providing beautiful atmosphere. It truly is the all purpose location for a family day as there is a 700' swimming beach, a dog park and even a nature lodge.

Todd Robertson at Blue Heron Lake (Photo by Diane Lowry)

Paddlers have 232 acres of lake to explore. There is a boat ramp located just inside the entrance to the park and for motor boaters, the lake is no-wake. In the very back of the lake you will find an area where motor boats will have to cut off their engines and most of the year, can't even get to because of shallow water. This is the "sweet spot" for paddlers. In the southeast section of the lake, just pass the buoy markers, you'll find a little slice of wildlife heaven. You'll see otter, beaver, muskrat and whitetail deer. Try this area out at sunset for maximum wildlife viewing. The lake is managed by the Iowa Department of Natural Resources.

Blue Tuesday is open to all paddlers at all skill levels. Paddlers can gather together every Tuesday through late fall to socialize, nature watch and practice skills in either canoe or kayak or even stand up paddle boarding. Paddlers begin to show up around 6pn and can paddle until dark. Due to my hectic DNR schedule over the last few months, even I have had nights where I could not make it right at 6pm, but please start paddling even if you don't see someone. Non club members often paddle the lake and this is a great time to introduce yourself and get them involved with CIP. Paddlers usually meet at the boat ramp, located just inside the main park entrance off Grand Avenue in West Des Moines. You can visit Raccoon River Park for more information and maps.

CIP Members Gary Stone & Dan "Danno" Whitmore at Blue Tuesday (Photo by Todd Robertson)

Mary Hyland

You are invited to Hardin County and The Iowa River Greenbelt area for two days of paddling on the Iowa River.  On Saturday June 11^th we will paddle from Eagle City to Steamboat Rock.  On Sunday June 12^th let's paddle from Alden to Iowa Falls with a stop at Camp David Restaurant for brunch.   Feel free to paddle both days or just on Saturday or Sunday.

• We will meet at take out both days and leave the majority of the vehicles at take out. 

• I have a ten stack canoe/kayak trailer that we can use to transport boats to put in.   

Day One - June 11^th

Eagle City to Steamboat Rock 13 miles

Meet @ 11:00am at our take out - Hardin County Access at Pine Ridge Campground located on the west side of Steamboat Rock - for shuttle.   (Paddling Iowa/Iowa River/Trip #2)

Note: Eagle City Winery is just up the road from the EC Access and we can stop by for a visit prior to our put in if anyone is interested.   Option at the end of our paddle:  Grab a taco at the Taco Trailer in Steamboat Rock.  (yum) ...and perhaps a beer at the Frozen Gator.

Day Two - June 12^th

Alden to Dougans Landing (Iowa Falls) to Camp David Restaurant 6.7 miles.  Meet @ 9:30am at our take out - Dougans Landing in Iowa Falls for shuttle. (See Paddling Iowa/Iowa River/Trip #1)

It is a short paddle from Dougans Landing to Camp David Restaurant; we can get out at the dock, and take the elevator to the restaurant.   Sunday Brunch served from 11:00am to 2:00pm.

Lodging

Overnight accommodations include a modern campground at Pine Lake State Park near Eldora and Pine Ridge County Park near Steamboat Rock.  There is also primitive camping along the river at the Cross Ford and Eagle City accesses.   Iowa Falls has two hotels and a bed & breakfast.  My home will also be available - extra bedroom and finished basement or camping in the yard. 

• Please come prepared for water and weather conditions.  Plan to wear your PFD.
• The trip is subject to appropriate weather and water conditions.

If you let me know you will be coming I will make an effort to inform you of any changes in plans.

Contact info:

Mary Hyland

Email:  paddlegirl57@yahoo.com

Cell:    641-373-6302

Lyle Danielson

At few short years ago during a paddling trip on the Raccoon River, I watched in horror from the opposite bank as a young woman on inner tube floated into a strainer. Strainers are tree branches and trunks lying in the river that allow water to flow through but entrap solid objects like inner tubes, boats and humans. Fortunately another young man jumped to action and pulled the woman to safety before she could be completely ensnared and drowned.

There exists only one other hazard more perilous to paddlers than strainers - the hydraulic. Hydraulics form when water flows over a shelf or ledge and drops into a pool or flat river bed. When the down-flowing water hits the bottom, it is forced back up with water flowing downstream from the boil line, but a significant portion of the water is recirculated back against the obstacle that it poured over.

In Iowa low head dams by nature of their construction create the most dangerous hydraulic conditions. These "drowning machines" almost always feature a continuous recirculation that offers deadly consequences for any person encountering them. The strength of the hazard depends on a variety of factors including the height of the dam and the velocity and volume of the river flowing over the dam. Concrete walls at either end of the dam prevent escape at the sides of the hydraulic.

Other hazards at low head dams include entrapped debris such as tree branches, logs and old tires. At higher water flow rates, the boil line often appears farther downstream from the dam face creating a longer drowning zone. You should expect water in a hydraulic to be highly aerated. The presence of significant bubbles in these waters reduces the density of the water and effectiveness of personal floatation devices. Recirculating waters often hold objects under the surface for extended periods of time.

Since it will be a long while before all low head dam hazards are removed in Iowa, river and stream paddlers must continuously be on the alert. Recognizing these hazards until too late can be deadly. Even small low head dams have horizon lines that are difficult to see when approached from upstream. At places like these, drops of only 14 inches have been known to lead to tragic results.

The ability to read the river and to recognize deadly hazards takes time and experience. Conduct pre-trip planning by consulting experienced paddlers, published guides and other internet resources. River users should be alert for warning buoys or signs that may warn of a dam ahead. Not all dams are marked! Watch for smooth horizon lines across the river. Be especially wary when these horizon lines have concrete walls at either end. Take heed of portage advisories. Be sure to take out well above any known dam and reenter well below any boil line created by the dam.

Already in 2011 two drowning fatalities and a close call have resulted from boating accidents involving boaters who were not wearing personal floatation devices. Everyone on the river is required to have a PFD, but it is useless to you if it is in the car, stowed or otherwise out of reach. Come on, it's OK to wear your PFD. Paddle smart, paddle safe and have a great paddling season out there.

For more information about low head dams in Iowa, check out http://www.iowawhitewater.org/lhd/index.html