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(established 8 Nov, 2019, updated Oct 2022) For discussion of arcane issues about river levels, gauges, and how best to use them for enjoyable and safe trips. Please post your ideas, observations or finds - directly here - or send them to

I'm sorry about the chopped-off entries. To read them, please open this page as though to enter changes - and enlarge to max,


-New USGS Water Dashboard - 1/2021 and 7/2022

- Need for Gauge at Loch Raven Dam (Lower Gunpowder Falls)

- Hollofield (Patapsco) Gauge - on the Chopping Block

- Petersburg Precipitation Gauge scrubbed

- How to Predict Volume at the Needles

- The Elusive Gauge at Harpers Ferry

- Critique of American Whitewater's New Gauge Reporting System (Parts I & II)

- Brandywine Ck USGS Gauge at Chadds Ford, Penna.

Some things have gotten better and some have not, as American Whitewater continues to refine the redesign—launched two years ago—of its state-by-state River Info pages.

A key safety-related issue remains, although it was called to AW's attention two years ago (and was written about in the Cruiser of March-April 2019—can you imagine that failing to have an impact?): "High Runnable" and "Low Runnable" levels are not stated. There's still one, less informative "Runnable" category, an invitation on some runs for the unwary to get on a river that's flowing well above their skill level.

Kayaker and gauge maven Tony Allred also has emphasized in discussions with AW that the state summary page and river detail page typically are out of sync when multiple gauges are referenced for a particular run. This is particularly confusing when the gauge worth relying on is an algorithm-based "virtual gauge" drawing information from multiple real gauges (good local examples: Lost, Lower Gunpowder, and South Branch Patapsco). 

If you're really dedicated, you may be able to get the virtual gauge reading to display by using the "Selected Gage" dropdown on the Flow tab. For example, for the South Branch Patapsco, you have to know that the virtual gauge is the one labeled "Woodbine to Henryton"—which is not necessarily the one displayed on the Flow tab by default, on the General tab, nor on the Maryland summary page. Hint: the Flow Range on the General tab probably will not refer to the virtual gauge, and if it doesn't, this information is not stated on the Flow tab either. You might be able to get a visual display of the data, though, depending on how high the river ran during the past year, if you select the virtual gauge on the Flow tab and then use the Data Timespan dropdown to show a full year of readings in the graphic. How's that for Gauge Geeky!

This confusion is a shame, because refinements like virtual gauges are one of the ways in which the AW site can add significant value beyond what paddlers can get simply by bookmarking and going directly to their favorite USGS pages.

On the plus side of the ledger: 

  • The river detail pages and their multiple tabs are nicely presented now with a prominent map of the run at the top of the General tab and useful River Description and River Features information under headings below that. 
  • It's now somewhat less cumbersome to find links to the underlying USGS gauges—follow the gage link on the General tab to an intervening AW gauge page, which has a Source Gauge's Page link to USGS. 
  • They've made it a little bit easier to navigate to the state summary pages: at the top of any page, click on River Info and scroll down to the list of states. Hint: Because this is still awkward, bookmark the darn state page when you get to it the first time.

Feedback on the AW site can be sent to

USGS National Water Dashboard –- 1/2021 and 7/2022

7 - USGS NWD - by Larry Lempert in the Cruiser:

7 – USGS National Water Dashboard – Initial Impressions: by Alf Cooley - 24 Jan 2021 – rev 3 Feb 2021


  It was rolled out on October 30, 2020 – and is marked “Experimental.” I was told about it on 20 Jan 2021 and informed AW and the CCA gauge geeks on Jan 25. Later talked with Larry, Tony, Jenny, Ron Kn.


Here it is:


Here is the USGS’ press release:    Other links to info are below.


I contacted AW for their opinion.  Looking into it. 25 Jan and contacted our Gage Geeks for their views – esp Larry, Tony, Jenny Thomas, Ron Knipling  


The Service thinks it’s a breakthrough for use on a mobile device. Gary, however, found it’s easier to navigate the site on a computer than on an iPad. UNSURE


A U.S. map is the basis – then you go to the data, rather than vice versa. You then go to your area. – UNSURE IF BETTER

The introductory map is too hazy and light - but maybe there is a bright-dark setting somewhere. WORSE


You can spread out the map to the full extent of your computer screen – no waste space, no selvages. GOOD


Classic Graphs - If you don’t like the new gauge graph, you can go to the “Classic” form that we know so well. SAME


It is studded with links to Fb and Twitter – not certain why

Median Flows - The new form lacks the golden triangle indicating average volume for that day.  A box says that it enables median, but it only does that for Stage, not for the far more useful volume.  WORSE


The Basin upstream of each gauge is shown on the map, below the graphs. GOOD But there's no indication of the catchment area – unless you go to “classic” hit DATA and drill down to “Summary of All Available Data.”

The individual gauge readouts also include - below - a picture of stream course (like AW's, but also the outline of the watershed area above that gauge. BOTH GOOD It would be nice to have the area of the basin in square miles.


You activate layers on the map – and you can see the watershed outlines – How about adding the Streamstats feature to find catchment areas along the various streams?  GOOD


It doesn’t stop at state boundaries, so you do not have to go looking in Penna, Md, Va, WVa sub-sites. GOOD


Layers - which show Rivers, Watersheds, Aquifers


It can show current weather on the map. - GOOD


You can measure straight line distances. GOOD


The pop up charts are obtained merely by hovering over a point – you don’t have to select them, then un-select them. – BETTER


The initial charts indicate if level is rising – stable - falling – BETTER


The pop-up charts do not extend up above the screen – BETTER


It has water alerts – now called “subscribe”  SAME


We are posting early notes on the NWD in the Gauge Geeks part of the CCA website and will write an article on it for the Feb/March 2021 CCA Cruiser. Contributions appreciated.




Hello, Kevin Colburn – 25 Jan 2021,

  I'm writing to ask what AW thinks of the NWD that the USGS rolled out at the end of last October. I came across it last week as I was preparing to give a talk on my CCA Stream-Finder tool to the MD/DE/DC Water Science Center. It looks interesting and will possibly revolutionize the way the Service presents its water data.

  I wonder who in AW is following this, whether you've had any input, and whether the pending change will have any impact on AW's own stream-gauging system.

   I'm writing up an article for the CCA's Cruiser - to appear in a couple of months. It would help to hear what you guys have to say.  Gauge Geeks Forum USGS has developed a new website incorporating a number of features currently found in their stream measurement programs. Since it has not completed rigorous testing, its information is provisional, But it appears that it will be the preferred way that USGS will be presenting their water information. First, it is presented as a map - and from the map you get to the gauges, the reverse is now the case. It shows not only streamflow, but rate of change - like Am Whitewater.

Please add your observations below. ( Please put opinions into parentheses) - Alf Cooley - 24 Jan 2021 -

  The NWD was rolled out on October 30, 2020 – and is marked “Experimental.” (Gary found it’s easier to navigate the site on a computer than on an iPad.  One nice feature, go to a stream and the basin for that stream is shown on the map, below the graphs.)

Here it is:

Here is the USGS’ press release:  

We are posting early notes on the NWD in this Gauge Geeks part of the CCA website and will write an article on it for the Feb/March 2021 CCA Cruiser. Contributions appreciated.

Need for Gauge at/below Loch Raven Dam (Lower Gunpowder Falls)

We hear that the biggest paddling desire in the Baltimore area is to have the Baltimore City's record of the quantity, in cfs., of what's going over Loch Raven Dam (the City manages the Dam), either directly or from a gauge downstream of the Dam. The City has to be keeping track of this, at some level. It would be nice if this could be put on the USGS gauge page so we wouldn't have to drive down to look at the Lower Gunpowder to see if it's running. (Tony Allred - 15 Dec 2020)

Hollofield (Patapsco) Gauge - on the Chopping Block -

This gauge, critical for the Class II-III Patapsco run through Ellicott City, is to be terminated on Dec 31, 2021. Probably because, with the Bloede Dam removal completed, it is no longer needed for safety. The Catonsville and Elkridge gauges downstream are also headed for oblivion. Too bad for the WW community. (Alf, 1 Dec 2020)

Well, on Dec 14, I called the number given on the USGS gauge page for Hollofield and spoke with the Baltimore Water Science Center's Chuck Walker, who gave me some background on why the gauge might be terminated. I noted that since 1992, the gauge has been axed 3x - with no readings over 12 years, but with smooth sailing since 2010. We'll see how we might extend this successful run.

Petersburg, WVa Gauge - Precipitation data is no longer kept, but WVA USGS people say that WVa is planning about 30 new gauges. Pie in the sky? (Alf, Oct 2019)

Estimating Volume in the Needles -

Suggestion on best gauges to use for this section of the Potomac just before the Shenandoah joins the Big River.

   There's no river gauge until Hancock, 62 miles upstream, so that measures flows from a day previous. To calculate Needles flow, take the Point of Rocks gauge reading and subtract Millville on the Shenandoah. WhiteHorse Rapid flow equals simply that at Point-of-Rocks.  

   Note, too, the catchment areas: Hancock: 4,090 sq mi. Needles: 6,313  Millville: 3,040, Whitehorse/Point of Rocks 9,354. - Alf Cooley

Gary Quam responds: In the trip report for last Thursdays paddle you mention the next upstream gauge from Point of Rocks is at Hancock. Actually there are two gauges in this section, a USGS gauge at Shepherdstown, and a gauge operated by the National Weather Service at Harpers Ferry. It is omitted from the USGS' listing of gauges. Its readings are only in feet, not cfs.  At the bottom of the site, it tells you what the consequences are of the higher stages.

The Harpers Ferry gauge webpage  has a note stating that the gauge does not read below 3.1’. I don’t think this is correct, as the last observable reading is 2.2’.  Some time ago I paddled over to take a look at the gauge. I found that the water level had to be about 2.1’ or above to contact the gauge.

Last Thursday the level at Shepardstown was 2.7’, 2610cfs, and 2.2’, 4116cfs at Harpers Ferry during the paddle. Ginny and I have found that when the Harpers Ferry gauge is up to 2.7 more lines open up at the top of Needles and it becomes much less scrapy.

Critique of American Whitewater's New Gauge Reporting System (Part II)

by Jenny Thomas & Tony Allred

First, on 1 Nov 2019, Jenny writes: I was just looking at the AW gauges for Maryland, Virginia, West Virginia and Pennsylvania to see what was happening given all the rain we are now getting. I was discouraged to see that the data has not been updated for over 20 hours so, once again, the AW river gauges are not useful for me. For those who are less experienced, the time the gauges were last updated is not immediately apparent or available on the state summary page. This could be dangerous for someone who gets on a river not having current water level information.  

As I reviewed our thread from last spring, I have noted that most of the issues raised by my fellow boaters and friends have not been addressed (see below). For a time, I was going to the AW river gauges as just a way to work my way to the USGS Source Gauge page, but I do not see any benefit of visiting AW’s river gauging summaries any more. The old system that was a critical tool for any boaters quiver has been replaced by something that is much less useful. I think that many boaters have been members of AW mainly because of the value of the gauging information. I suspect that AW will lose members because it is no longer useful for them. This is regrettable.


Jennifer Thomas

Then from Tony (1 Nov): 

I also have noticed (actually some time ago) that there are often significant delays in the updating of gauges on the AW site, and further, that this is not apparent, unless you click into the flow link and happen to notice the "flow rate as of 'x' hours ago." This in addition to the other gauging and presentation issues that have been previously raised and are still unaddressed. Because, since the web update, the gauge presentation on the AW pages are so consistently misleading, in my swiftwater rescue class in August, I began teaching that paddlers should go to the USGS pages and not the AW page for gauge information. You can't promulgate inaccurate, confusing and misleading information on the web for almost a year without losing your audience. In this sense, the damage is already done. 

Tony Allred Jr.

AW's Kevin Colburn responds - (1 Nov)

Hi Jenny, 

Thanks for the heads up. I have our programmer looking into what is going on with the lag time and working to fix it. This should be a bug rather than anything systemic, however occasional interruptions have always and will always be an issue. Here are a few updates for the crew regarding things mentioned above. 

Custom gage ranges. These are in place on the next update of the site that we are testing now. We recognize this is a need. 


Flow data tables: these are on the flow tabs. 

Links to gages go to the correct gage. 

Big picture we are investing a lot into our website right now. We are doing a lot of invisible back-end upgrades to modernize and simplify the code. The new site design already works well on mobile devices, is vastly easier to contribute river page content to, and has better mapping. We are working improve on issues like the ones you are raising, redesigning our safety page, integrating a more useful mapping interface, and making the apps work (and work well). This has been a huge lift for AW given the complexity and age of the site and our limited capacity. We are striving to deliver the best site as soon as possible. 

Thanks again for the feedback, and I certainly understand and hear your frustration. 

AW National Rivers Inventory: Paddlers Beware: by Larry Lempert - March/April 2019

(Critique, Part I)

Paddlers beware: a redesign of the much‐relied‐on American Whitewater website has changed the color‐coding to portray some rivers as "runnable" at levels that would be dangerous for all but expert paddlers. The redesign at, rolled out in January 2019 and supported by a U.S. Coast Guard grant, also has suffered from programming glitches that have caused certain detailed information about river levels to disappear from the site. AW has acknowledged that there were substantial problems with the rollout, and according to an email from National Stewardship Director Kevin Colburn, has bug fixes and enhancements coming "as fast as our programming team can crank them out." But AW hasn't commiƩed to any schedule, so Caveat Emptor is the watchword for now. 

The AW Beta newsletter says the foremost goal was to make it easier to edit river pages so important information can be shared. Colburn also has said that AW aimed for better display on mobile devices, use of a modern code base to facilitate enhancements, and more prominent placement of safety information. On a key matter of safety, however, the site used to have five informative categories: "Below Recommended," "Low Runnable," "Runnable," "High Runnable,"and "Above Recommended." These have been collapsed into three less informative categories, with the former "Low Runnable," "Runnable," and "High Runnable" now forming one "Running" category. This allows some potentially dangerous misdirections for the unwary who scan pages and focus on green as a signal for Go. For example, the Lower Yough remains green/"Running" between 4 and 7.5 feet; this is in stark contrast to the 2.0‐2.5 foot levels most paddlers are familiar with and at which the rapids are described. Stonycreek shows as green/"Running" up to 3980 cfs; if you didn't know Stony, you wouldn't know that 3980 is ripping high. Even worse, the Potomac LiƩle Falls run was being depicted as a benevolent green/"Running" when the LiƩle Falls gauge approached 6 feet—a far from benevolent level (at which you will NEVER EVER find me paddling LiƩle Falls!), that the prose descripƟon acknowledges as having Class V characterisƟcs. Fortunately, some page ediƟng has been done to override the LiƩle Falls misinformaƟon, but it's unrealisƟc to think that individuals can catch and intervene to manually adjust all the programming‐driven miscues. While it's true that the former site's runnability classificaƟons were someƟmes misleading, it's beyond argument that the redesign makes maƩers worse, not beƩer. The data that has disappeared (hopefully only temporarily) due to programming problems includes the detailed history of gauge movements throughout the day. Also, for each river, gauge informaƟon is now given in cfs or feet, but not both. While many trip planners prefer to know cfs, a lot of paddlers sƟll relate to levels in feet, and having both is beƩer than limiƟng the site to one or the other. In addiƟon, the site has made it much more cumbersome to get to the USGS source pages for the gauge informaƟon, although with persistence you can make it there. Even the state river gauge summary pages, the most helpful and heavily used pages on the site, are harder to get to now. Here are two Ɵps for those parƟcular issues: To access a river gauge summary page, from the top menu dropdowns select River Info, then NaƟonal Whitewater Inventory (how’s that for a user‐friendly label—NOT!), and then State Gauges to pick a state from the map or a list below. To access the USGS source gauge, from a parƟcular river summary page click on the Flow tab, scroll down to find and click on Gauge LocaƟon, then on the resulƟng page look for the link to Source Gauge’s Page. 

The site does render more readable on a mobile device, judging by its appearance on an Apple iPhone 7. AW has asked paddlers to bear with them while efforts to fix and enhance the site conƟnue and has suggested that feedback will be most valuable once the dust has truly seƩled (whenever that might be). If paddlers do want to provide input now, comments can be sent to Don't hope for even a temporary rollback to the old site while work conƟnues, though. Colburn says, "We can't switch between the old and new site because of complexiƟes with the vast database behind the site." 

Comment: Whether the AW site has achieved its goals of making it easier to edit pages and share informaƟon, I can't say, not having used that feature previously. With all the informaƟon it brings together, the AW site is a terrific resource and is well‐ deserving of the financial support that it seeks Note on New AWW Gauges response from AWW of inquiry by Barbara Brown. So the gauges. AWW redesigned their website so it works on mobile devices, encourages more crowdsourced content, has a modern code base for future enhancements, and places safety information more prominently. In the process of transitioning to the new site some wires got crossed and they are actively fixing bugs and enhancing design elements for a better user experience. This work will be ongoing, and they are making fixes and enhancements as quickly as possible given their small team. The gauge services of the AWW website work now, but will get much better in the coming weeks.

Brandywine Ck USGS Gauge at Chadds Ford, Penna. - Alf Cooley

This is the main gauge for the Brandywine, which ends in downtown Wilmington. It is distinguished by measuring not only precipitation in addition to the usual stage (height) and volume readings. But it has two sets of videocam images - the first shows today's pictures, hour by hour. The second shows the stream over the past 11 days - in 13 second intervals.    Do paddlers know of other such on-line gauge live cams?  

I know this has been suggested for the Belair Rd/Rte put in for the Lower GPF, but vandalism is feared.  Do they have a better breed up there in the Quaker State?

    Steve Ettinger led a Thursday trip up there in 2007 at 700 cfs - Gertler has 2 ft minimum (which translates into 251 cfs). Have there been any DC-area trips going up there since 2007 ?

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