Stories tagged river

Disaster junkies, prepare to be disappointed.

Hydrograph: 4/11/2011, 5pm
Hydrograph: 4/11/2011, 5pmCourtesy Advanced Hydrological Prediction Service

The National Weather Service says that the Mississippi River at downtown St. Paul has crested, again, at 18.71'. (Previous crest was on 3/30 at 19.1'.)

Forecasters say that the river will remain at this level for a few days before falling at the end of the week. And they caution that the model only includes precipitation anticipated in the next 24 hours. A lot of rain in the next few days could cause the river to rise. Again.

The river level here at downtown St. Paul has been going down since the crest on 3/30 at 19.1'. We're holding now at about 17.3', and the National Weather Service predicts that the trend will bottom out tonight at around 17.2' before the river starts rising again. We're expecting a second crest at about 19.5' on the evening of 4/10, but that prediction doesn't take into account any rain we might get later on this week. Stay tuned...

Here is a gigapan shot I took of the river yesterday. I will try to take a panorama every other day(at least). I intend to capture more of the river west in future shots.

http://gigapan.org/gigapans/73228/

BTW: pay special attention to the crazy time capture of a really long train that was passing by.

Please pass on the link to whomever you feel would be interested.

Rain and rivers

by Liza on Sep. 30th, 2010

Alright, it's absolutely beautiful outside today. So what's up with this predicted flooding?

Remember all that rain the week of September 20th? (We got 2-4" here in the Twin Cities, but areas to the southwest of us got as much as 10".)

Rainfall map
Rainfall mapCourtesy National Weather Service

It all had to go somewhere, and that somewhere was the Minnesota River. Why does that affect us here in St. Paul? Take a look at another map:

St. Paul and the rivers
St. Paul and the riversCourtesy NASA (Landsat)

Remember: rivers don't necessarily flow south. The reddish line is the Minnesota River. The blue is the Mississippi. And that little blip just north of where the two rivers come together is downtown St. Paul. (The yellow elipse is the area of highest rainfall.)

All that rain is flowing right past us. And it should be impressive. The river's at 15.4' this morning (moderate flood stage), and predicted to crest at 18' (major flood stage) on Saturday morning. But the recent spate of lovely weather means that the flooding should pass quickly--today's prediction has the water level back under 17" by Monday morning.

St. Paul police have closed all the river roads and parks, and are discouraging people from walking down by the river. But you can get a stellar view of everything from outside the Museum on Kellogg Plaza, or inside the museum from the Mississippi River Gallery on level 5.

Mar
20
2010

NOAA flood prediction: Up and up.
NOAA flood prediction: Up and up.Courtesy NOAA
When I woke up this morning and checked the NOAA flood forecast for the downtown Saint Paul station it was at 19.7 feet above the normal stage. Yikes, the forecast still keeps going up. The river is predicted to crest on March 24th (next Wednesday).

Other flood related resources from my morning browsing:

The StarTribune visits the NOAA, National Weather Service Weather Forecast Office, in Chanhassen, MN. The scientists at NOAA explain what's different about this year's snow melt...complete with some classic Minnesota accents.

Check out what downtown Saint Paul looked like in the 2001 Mississippi River flood. So far, no one's predicting this year's food will be as bad as that historic spring melt, when the river crested at 23.67 feet.

And, for purely nostalgic purposes, here's a pic of Minnesota Governor Karl Rolvaag (he's in front of the guy with a bag on his head), President Lyndon Johnson, and Senator Walter Mondale (looking quite dashing back in the day) standing dangerously close to the river in the really bad 1965 Mississippi river flood. The river crested at 26 feet that year.

Check out our full feature on the 2010 Mississippi River flooding.

Mar
19
2010

The Mississippi River here in Saint Paul is currently forecasted to crest at 19.8 feet next Wednesday and was measured at 12.9 feet at 7:00 this morning (Friday). All these river height numbers got me thinking about a really good question someone asked me last year about just what these numbers mean and how they are measured.

Stream gauge location: Readings of the Mississippi River at downtown St. Paul are taken by instruments here.
Stream gauge location: Readings of the Mississippi River at downtown St. Paul are taken by instruments here.Courtesy USGS

Here is an explanation: The Mississippi here in Saint Paul started being measured way back in 1893. The actual location of the measurement station is right by the High Bridge on the west side of the river. Currently the station is operated by the US Geological Survey and the US Army Corps of Engineers. At the time that the station was established, an arbitrary 0 measuring point was chosen (probably the bottom of the channel at the time). When the river reaches 14 feet at this station it is pretty much flowing above its banks in the vicinity of the gauge. All this is to say that the gauge numbers aren't really measuring anything specific about the river other than its height above a point established over a 100 years ago. This means that gauge readings can only be compared to other readings at the same gauge.

Kate's photos, 3/18 (2): Look across the river to the floodwall: thats the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and spelled the end for the communities down on the river flats.
Kate's photos, 3/18 (2): Look across the river to the floodwall: thats the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and spelled the end for the communities down on the river flats.Courtesy Kate Hintz

So if you call up your friends and family in Fargo/Moorhead today to compare notes about who is experiencing the worst flooding, you'll find that your Mississippi River measurement of 12.9 feet doesn’t look impressive by the measurement of over 35 feet at Fargo. And, your 12.9 feet will seem straight up puny compared to the 677 feet the Mississippi is flowing today at Prairie Island, Minnesota, where the river is measured against elevation.

For details on just how river gauges work, check out this explanation the US Geological Society offers.

Noteworthy flood heights in Saint Paul:
14.0 Portions of the Lilydale park area begin to experience flooding.
17.5 Harriet Island begins to become submerged.
18.0 Warner Road may become impassable due to high water.
19.8 Forecasted crest
26.4 Record 1965 crest!

Want to learn more about floods and the Mississippi River? Stop by the Mississippi River Visitor Center in the lobby of the Science Museum and talk to a National Park Ranger!

Check out our full feature on the 2010 Mississippi River flooding.

Volunteers in Fargo have been busy this week - they've placed 700,000 sandbags along the river, which should protect them from a flood of up to 40 feet. The rivers in North Dakota have also been busy — they've been tweeting.

Using data from the National Weather Service, these Twitter accounts are set up to pull in current river levels from several locations along a few different rivers:

http://twitter.com/jamestownflood (James River in Jamestown, ND)
http://twitter.com/VCfloodstage (Sheyenne River in Valley City, ND)
http://twitter.com/egffloodstage (Red River in Grand Forks, ND)
http://twitter.com/fargofloodstage (Red River in Fargo, ND)
http://twitter.com/oslofloodstage (Red River in Oslo, MN)

Check out our full feature on the 2010 Mississippi River flooding.

Mar
18
2010

If you're visiting the Science Museum of Minnesota, look out the windows from the Mississippi River Gallery on level 5. If you're in downtown St. Paul, stop by the museum and look at the river from the overlook on Kellogg Plaza. (City officials are asking folks not to flock to areas where barriers are going up - especially Harriet Island - but the view from in or around the museum is spectacular and safe.)

Kate's photos, 3/18 (3): Looks peaceful, doesn't it? Still, the city is warning people to stay off of the river, out of the low-lying parks, and away from Harriet Island and Water Street.
Kate's photos, 3/18 (3): Looks peaceful, doesn't it? Still, the city is warning people to stay off of the river, out of the low-lying parks, and away from Harriet Island and Water Street.Courtesy Kate Hintz

The Mississippi is going up FAST today, and forecasters expect that the river will officially reach "flood stage" by early this afternoon. (It's 10:45am, and the river's at 11.67'. It's risen a foot and a half in the last 24 hours, should reach 12' ("action stage") pretty soon, and 14' ("flood stage") by late today.

Kate's photos, 3/18 (2): Look across the river to the floodwall: that's the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and marked the end for the communities then down on the river flats.
Kate's photos, 3/18 (2): Look across the river to the floodwall: that's the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and marked the end for the communities then down on the river flats.Courtesy Kate Hintz

Kate's photos, 3/18 (1): Shepard/Warner roads will close from Chestnut Street to US 61 starting Saturday morning, and could remain closed for weeks. Take your river sightseeing drive/bike ride/walk before then!
Kate's photos, 3/18 (1): Shepard/Warner roads will close from Chestnut Street to US 61 starting Saturday morning, and could remain closed for weeks. Take your river sightseeing drive/bike ride/walk before then!Courtesy Kate Hintz

So what's going on around the river?

  • The city has closed all city boat launches and temporarily banned all recreational boating within the city limits.
  • Water Street will be entirely closed, starting this afternoon.
  • Hidden Falls and Lilydale regional parks are closed.
  • Flood barriers are going up at the St. Paul downtown airport and at Harriet Island.
  • Harriet Island will close once the river reaches 17'.
  • Warner/Shepard Roads will be closed from Chestnut Street to US 61 starting Saturday morning in preparation for the construction of a temporary levee that could withstand river levels to 26'. These roads could be closed for weeks, depending on the extent of the flooding.

Here's the latest hydrology graph:
3/18 hydrology graph, 10:15am
3/18 hydrology graph, 10:15amCourtesy USGS

Check out our full feature on the 2010 Mississippi River flooding.

Mar
17
2010

Look out the window or walk down the street to nearly any river or stream in Minnesota right now and you are likely to observe two things about the river:

  1. it is getting deeper (or “rising” in relation to the banks); and
  2. it appears to be moving faster.

You can, of course, confirm these observations by investigating reports from gauging stations along these rivers, maintained by the U.S. Geological Survey. (See data for the gauging station serving downtown St. Paul.) But what is really happening?

It may be high and fast...: ...but (as of today) the Mississippi at St. Paul is still in a bankfull state.
It may be high and fast...: ...but (as of today) the Mississippi at St. Paul is still in a bankfull state.Courtesy Liza Pryor

Until a river flows over its banks, it is considered to be in a “bankfull” state. In this state, the water flowing through the river is confined to a relatively fixed channel area. Simply put, floods occur because more water is being introduced into this channel from upstream, due to snowmelt, heavy rains, or a dam breach. As this added volume of water moves through a fixed area, it both increases in velocity and in depth until it overflows the banks, at which point some, but not necessarily a lot, of the volume and velocity moving through the channel are reduced.

Scientists call the rate of flow through a channel “discharge." Discharge is defined as the volume of water passing through a given cross-section of the river channel within a specified period of time.A simple equation for determining discharge is

Q = D x W x V

where Q = discharge, D = channel depth, W = channel width and V = velocity.

Looking at this equation, it is easy to see that if discharge becomes greater and channel width is fixed, then an increase in both volume and depth (or height relative to the banks) is likely to be the cause. Discharge can be measured in cubic feet per second or cubic meters per second, for example.

But is the river flowing at the same rate at the surface as it does along its banks and beds? Understanding this requires investigating some more detailed equations, as the banks and bed introduce friction, which affects the rate of flow.

To learn more about rivers and how they flow, you may want to check out the works of Luna Leopold, and M. Gordon Wolman. In particular:

  • Leopold, Luna B. (2006, reprint). A View of the River. Harvard University Press; and
  • Leopold, Luna B.; Wolman, M. Gordon; and Miller, John P. (1995). Fluvial Processes in Geomorphology. Dover Publications, both classics for understanding how rivers work.

Also, check out our full feature on the 2010 Mississippi River flooding.

Jun
14
2009

Mouth of the Columbia River
Mouth of the Columbia RiverCourtesy U.S. Army Corps of Engineers Digital Visual Library
Have you ever wondered what happens when a river ends and the ocean begins? Well, the scientists at the Center for Coastal Margin Observation and Prediction (CMOP) do. Based out of Oregon, the center conducts their research on the Columbia River. Their goal is to understand and predict how humans and the climate affect the costal margins. The research has three themes, to test and advance the way research is done, to understand the human and natural variables that affect the margin, and to integrate the two previous themes to create a functional research station.

So, are you still contemplating the question, what is going on in this unique area where fresh water that has travel the country meets the salty water of the ocean? Well, the center has opportunities for K-12 students and teachers and undergrad and graduate students to become involved. Everything from summer camps and programs for middle and high school students to internships for the undergrad and grad students. Not interested in traveling? Data is also available on their website for the free-lance researcher.

Before the next time you jump into the big blue, quench your thirst for knowledge and see what CMOP is doing to research and preserve the coastal margins of the Columbia.