Hi All,

 

In a few other threads I've used some online tools to help others understand their lakes and what was going on with them without actually being there.  I realized that not everyone will have seen all of the things available online so I wanted to have a reference thread that people could come back to.  For background, I'm an engineer and like data and interpreting data.  I'm also a bass fisherman.  If you polled my bosses and my fishes, I'm probably a better data person than bass fisherman.  So I'm not telling you how and where to fish in this thread.  I'm not saying that 51 degrees is magical number when fish bite.  I'm just saying that if you want to know whether your lake is at your own magical temperature and height, here are some tools to find out.

 

Also, I know a lot of tools, but I definitely don't know all of them.  New ones come out all of the time.  I'm only going to reference ones that I know and use.  There are a few more that I've tried and they haven't worked out so I won't mention them here.

 

First up is USGS.  You might have seen USGS monitors on buoys in your lakes, in roadside ditches, or various other places.  There are tons of different monitors for lakes, streams, rivers, canals, and estuaries/coastlines.  They measure things like water height for simple ones all the way up to pH, fluorescence (for algal bloom monitoring), sediment, or anything else deemed important enough to check in that station.  In the past, the data has been available, but the online interface has been very text and table based.  Its now in a great graphical web interface.  Every station has its own web page.  The national map has layers, toggles, and other data overlays.  Let's look at some examples:

 

USA Hydro Map

 

 

This is a broad map of the full US with some station data that I use, specifically, I've turned on streamflow (status), surface water (lakes), and water quality (temp).  Each dot is a station and tells its own story.  Each has a shape representing the type of station- circles (streams and rivers), squares (lakes), diamonds (springs), etc.  The colors represent where the stream flow is relative to normal this time of year.  Black/blue is really high, greens are normal, red is low.  There are other color indicators but the main other one I use is yellow which represents a station monitoring temp.  Looking at the map from today (above), you can see where rain has hit the north east, south east, and south recently.  You can see that everything from Wisconsin to Montana and down to Nebraska is largely icy (the brown dots are 'affected by ice').  You can see California streamflow has largely recovered from the recent floods.

 

Getting more specific I'll use NJ as examples.  This is my saved link view.  I have the same stations turned on for the above map, but its zoomed to my region.  From here, I'll navigate to various station maps to see what is going on with each.  You'll notice there aren't many lakes with temperature monitoring, so there is a little interpretive work needed.  Streams can begin to inform, but you need to consider if you just had a heavy cold rain, low water and lots of sunshine, etc.  Lake and stream levels are also useful to understand what conditions you're going to see when you get there.  From this map I can see that the streams are flooded and the lakes should be gaining water.  If you are interested, you can add other layers such as topography, street maps, even public transport maps.  Want to know the closest trainline to your lake?  Its there.  You can look at the hydrology and which rivers and streams flow into which lakes.  Does your lake barely change when it pours down rain?  Check how big the catchment area is of the streams that feed it- its probably small.  

 

One lake that I monitored a lot this year is spruce run (you can see it in the bottom left of the map- square dot).  I started fishing it last year.  Its 1300 acres of mixed cool and warm water fish- smallies, largemouth, hybrid stripers, pike, panfish, trout (washed in from streams above), herring forage.  Its restricted to 9.9 hp so a good kayak lake (negligible pleasure boats).  Good fishing.  It's also used to supplement waterflow to the downstream river (south branch raritan) in times of low rain.  Last year we had about 1" of rain over 60 days, so there was a lot of supplementing.  As I mentioned, each station has its own USGS page.  This is it for Spruce run lake (very zoomed out):

 

 

The base data is current conditions for the past week which is fine if you want to know right now info.  But you can do a lot more with it.  One point of data doesn't make a trend, but you can expand the data to as far back in time as the data was measured.  This lake only installed temperature last year, but if you wanted to see approximately when you hit that magic temp, expand the time span to be 5 years. Here's a temperature example for Lake Murray (SC) for the past 5 years or so.  If I'm looking for 60 degree water, that's the first or second week of April in the spring.  Planning a trip?  Look for lakes around it with similar characteristics.  You could use lake Murray as a decent proxy for Santee Cooper (that's what I was looking at).  

 

 

Surface elevation is useful too.  Spruce is nominally full at 273'.  You can see the clear flat top to the graph in that area.  You can also see the normal summer reduction about 8' low in past years.  2021 was a reasonably wet summer so it stayed pretty full and steady.  Last year though, it went off a cliff.  That was the second lowest its been since data started here.  How do you use this info?  Well to start, get familiar with your lakes that have monitoring and you can start tying data to actual conditions.  We don't have a ton of lake monitoring here, but I know if Spruce is down 10', the natural lakes around here will be down at least a foot (and when spruce was 20' low the natural lakes were 2' low with no outflow).  Also, for the monitored lake, you can start building other information.

 

 

First, you can tie water level to actual fishing conditions.  I fished the lake at full pool in April and May.  I have a pretty good idea where fish are holding at that water level.  When I went back in august, it was about 10-12' low.  It later bottomed out at 22' low.  Do you take pictures of your lakes on your phone?  If so, you have a treasure trove of data available to you.  Here are some pics from my visit in August where you can see what's normally covered in water.  I have a lot more of things you'd have never known was there.  I can now tie the dates on the pictures to water levels.  The waterline in these pictures is at nominal 11FOW at full pool.  The tree comes above the water, but now I know if its full pool there is a lot more under there than you can tell.  I often take pictures of my Humminbird either when taking pictures of fish or of the lake.  That helps confirm water temps vs USGS and for a given date.

 

 

 

 

The next tool to tie in is Navionics online.  Many of you will know navionics from your fish finders.  There is also an app (paid I think).  The online version is free.  

https://webapp.navionics.com/?lang=en#boating@2&key=maeyFfv`kP

 

I've found navionics online to be the most accurate depth data of any of the online tools.  It may miss some detail on lakes with limited data, but generally it is very close.  The more popular the lake the better the data.  How do you use it?  For me, its two things: 1- scouting on lakes I've never fished and 2- finding patterns with varying lake levels.  Scouting is obvious and discussed elsewhere.  If you want to fish bluff walls, sloping points, of big flats you can find them.  The clever thing is using USGS data and Navionics to see what those areas look like now.  Navionics will let you set safety depths where it highlights various depth ranges.  The app is even better for it and allows multiple ranges and colors.  Below is the same spruce run at 12' low.  Anything in blue is dry land. 

 

 

Want to target dropoffs that go from 10' to 20'?  Just use the contour data and subtract 12 from the numbers.  On the map you'd look for 22'-32' at full pool.  Here would be some likely places (I graphed fish there when it was the water level).  The data can't tell you that fish are there or that your intuition is right.  It can help you narrow down the places to look though.  If you're using the free versions, you can then just drop some pins in google maps and confirm precise locations with your boat's electronics.  

 

 

 

 

There are other water resources available on the net.  The US Army corps of Engineers is one.  The data is sometimes fragmented by region and not as simple as USGS.  I've linked to the Detroit region and great lakes below.  If you have a specific Corps lake, google is your friend. 

 

California uses lakes for water supply and the local water control boards have water data as I found in the thread with Darth-baiter.  Here is one example of the same.

 

https://cdec.water.ca.gov/index.html

 

There are other online resources available and if you have a good one, please post it below and what you do with it.  If you can't get out on a lake or have minimal time available, sometimes online scouting is just what you need to be ready when you are there.

 

thanks,

Rick

Man, it’s gonna take me a while to digest all this. Really appreciate you spontaneously throwing this out; there is a ton of info here. 

Google Earth is another good scouting source of lake history. Checking different date views when the lake is down and marking weigh point on rock piles, stumps and whatever else you see that might be productive. Edwin Evers has a video on you tube discussing how he does it.

FM

Thank you for posting this!

27 minutes ago, Fishingmickey said:

Google Earth is another good scouting source of lake history. Checking different date views when the lake is down and marking weigh point on rock piles, stumps and whatever else you see that might be productive. Edwin Evers has a video on you tube discussing how he does it.

FM

 

Yes, very true.  If you have a desktop, the desktop version of google earth allows you to roll back time and see the lake when it is low (which you can then correlate to USGS water data).  I can't do that in google earth for ipad and I can't install Google earth on my work desktop so I forget about it.

No problem,  Thank you for you very informative post regarding the GS Hydro maps.  I'll have to check them out for my next tournament. 

Best regards,

Fishingmickey

18 hours ago, casts_by_fly said:

First up is USGS

 

Someone round here been preaching that for years. 

2 hours ago, Catt said:

 

Someone round here been preaching that for years. 

For good reason!  But the old website was cumbersome and the data sometimes limited (or the ability to find or manipulate the data limited) so I can see why a lot of people couldn't be bothered.

 

is there a USGS or equivalent for Toledo Bend?  I looked when I wrote the post above but couldn't find anything on USGS website.  

27 minutes ago, casts_by_fly said:

I can see why a lot of people couldn't be bothered.

 

They ain't dedicated enough!

 

I got a whole stack of Toledo Bend maps from USGS along with survey maps from prior to the lake being impounded.

 

Some state or counties will have servey maps.

 

Before the WWW you had to be a gumshoe detective!

51 minutes ago, Catt said:

 

They ain't dedicated enough!

 

I got a whole stack of Toledo Bend maps from USGS along with survey maps from prior to the lake being impounded.

 

Some state or counties will have servey maps.

 

Before the WWW you had to be a gumshoe detective!

 

I found some 'live' data.  2011 looks like it was rough.  60% full.  Must have been 8-10' low

 

https://waterdatafortexas.org/reservoirs/individual/toledo-bend

25 minutes ago, casts_by_fly said:

I found some 'live' data.  2011 looks like it was rough.  60% full.  Must have been 8-10' low

 

Actually it was a phenomenal year, the low water constrated the bass on specific structure. 

This is immensely useful.  Many thanks.