# Is there an app to determine the "head" of a stream? **URL:** \ **Category:** Factual Questions\ **Created:** [March 4, 2015, 3:34am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173 "2015-03-04T03:34:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 4, 2015, 3:34am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/1 "2015-03-04T03:34:00Z")
I am installing a mini hydro electric system in the stream that runs along the property line to power my home. I need to determine the “head” or height of the highest point of the stream below the waterfall and the low point where the hydro turbine will be set up. A four inch pipe that begins near the top of the waterfall will carry the water to the unit. The pipe runs down along the wall of the canyon. The palm and banana trees and other vegetation are thick and difficult to go through. You can’t begin to see the bottom of the canyon from where the upper piece of pipe is located. The “head” will determine how much electricity the system will generate and what kind of unit I need. Is there an app for this? ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [March 4, 2015, 3:40am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/2 "2015-03-04T03:40:16Z")
See [here](http://www.canyonhydro.com/guide/HydroGuide7.html) ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [March 4, 2015, 3:49am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/3 "2015-03-04T03:49:20Z")
The GPS altimeter and possible barometer in your phone are unlikely to be accurate enough for this. Are you somewhere reasonably well-mapped? Maybe you can try the Google Earth method? [http://www.appropedia.org/How\_to\_measure\_head\_for\_microhydro\_with\_Google\_Earth](http://www.appropedia.org/How_to_measure_head_for_microhydro_with_Google_Earth) If not, am77494’s manual method might be the way to go. Here are a few more manual methods involving hoses and the such: > **[Planning a Microhydropower System](https://www.energy.gov/energysaver/planning-microhydropower-system)** > > Interested in a microhydropower system? To see if a microhydropower system would work for you, determine the vertical distance (head) available and... ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 4, 2015, 3:51am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/4 "2015-03-04T03:51:45Z")
Method one: Surveyor’s transit The canyon is much too thick with trees to use a surveyor’s transit. You just can’t see the bottom from the top. Method two: Garden hoses The stream is over 200 feet long and goes down over some rather treacherous terrain. Trying to place several garden hoses in the stream would be impossible. Thanks for the link. ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [March 4, 2015, 4:19am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/5 "2015-03-04T04:19:46Z")
You don’t do the whole stream at once, but break it down into manageable sections and then add it all up at the end. Did you try the Google Earth measurement? If your area is well-surveyed, it might be accurate enough for your needs. If you want to try the smartphone, just get a [generic GPS app](https://play.google.com/store/apps/details?id=com.eclipsim.gpsstatus2) and let it acquire a good fix on several satellites and see if the altitude is accurate enough. Write down the altitude at the top and bottom and there’s your head, no special app needed. Or get the horizontal GPS position at both locations and measure them on Google Earth afterward. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [March 4, 2015, 1:04pm UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/6 "2015-03-04T13:04:53Z")
Here is a method I suggest : 1a. Less accurate due to the possibility of air traps: Take a fishing pole with reel etc. Tie a large float (tennis ball or similar) - stand on the top of the stream and let the float come down in the waterfall while you let the reel go. When you come down to the base of the waterfall, you will see the floating ball. Now buy 300ft clear flexible hose from a hardware store, fill it with water avoiding air bubbles in the system. Attaxh a pressure gauge to one end. Tape the other end to the float / tie it. Pull the end up by reeling in the fishing pole while keeping the pressure gauge at the bottom. Once you have reeled it all the way to the top, the pressure guage will give you the head. 1b. If you want more accurate head, attach a pump at the bottom before the pressure guage and pump water at a high rate to take out all the air trapped in the tube. ---
**Author:** ![chappachula](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@chappachula](https://boards.straightdope.com/u/chappachula)\ **Post date:** [March 4, 2015, 3:10pm UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/7 "2015-03-04T15:10:40Z")
> [@Mangosteen](#): > > I need to determine the “head” or height of the highest point of the stream below the waterfall and the low point\*\* where the hydro turbine will be set up.\*\* > > The palm and banana trees and other vegetation are thick and difficult to go through. You can’t see the bottom of the canyon I’m confused…you can’t see the bottom, but you want to set up a turbine there? Won’t you have to move through the vegetation-- carrying tools, construction equipment, and the turbine itself?. Find a route down there, and hire a professional surveyor to follow that route with his equipment. If somewhere near the bottom, close to your turbine, there is a clearing with visiblity to the sky, a professional surveyor has GPS equipment that can measure that spot to one-centimeter accuracy, and then from there maybe it’s only a short distance to the actual location of the turbine, easy to measure. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 12:15am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/8 "2015-03-05T00:15:44Z")
> [@chappachula](#): > > I’m confused…you can’t see the bottom, but you want to set up a turbine there? Won’t you have to move through the vegetation-- carrying tools, construction equipment, and the turbine itself?. > > Find a route down there, and hire a professional surveyor to follow that route with his equipment. > If somewhere near the bottom, close to your turbine, there is a clearing with visiblity to the sky, a professional surveyor has GPS equipment that can measure that spot to one-centimeter accuracy, and then from there maybe it’s only a short distance to the actual location of the turbine, easy to measure. The pipe (and only the pipe) is installed. At the top, an intake value will be placed in a pool under one of the waterfalls. This intake valve will be attached to the upper end of the pipe. The turbine will be installed at the bottom of the pipe. There is a way to get from the top to the bottom without going through the vegetation. Installing the pipe along the canyon wall just above the stream was a nightmare, but at least this part is done. Before I install the turbine, I have to find out how much head I have so I get the right type and size turbine. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 12:20am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/9 "2015-03-05T00:20:01Z")
> [@am77494](#): > > Here is a method I suggest : > > 1a. Less accurate due to the possibility of air traps: > > Take a fishing pole with reel etc. Tie a large float (tennis ball or similar) - stand on the top of the stream and let the float come down in the waterfall while you let the reel go. When you come down to the base of the waterfall, you will see the floating ball. > > Now buy 300ft clear flexible hose from a hardware store, fill it with water avoiding air bubbles in the system. Attaxh a pressure gauge to one end. > > Tape the other end to the float / tie it. Pull the end up by reeling in the fishing pole while keeping the pressure gauge at the bottom. Once you have reeled it all the way to the top, the pressure guage will give you the head. > > 1b. If you want more accurate head, attach a pump at the bottom before the pressure guage and pump water at a high rate to take out all the air trapped in the tube. Its a very treacherous stream with many rocks, waterfalls, twists and turns. I’m afraid the tennis ball would get hung up along the way and never make it to the bottom. ---
**Author:** ![Dickerman](https://avatars.discourse-cdn.com/v4/letter/d/8baadc/32.png) [@Dickerman](https://boards.straightdope.com/u/Dickerman)\ **Post date:** [March 5, 2015, 12:43am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/10 "2015-03-05T00:43:09Z")
If you raised a balloon on a string at the lower end to a height that’s the same as the upper end of the pipe, would you be able to see it from the top? ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 1:56am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/11 "2015-03-05T01:56:24Z")
> [@Dickerman](#): > > If you raised a balloon on a string at the lower end to a height that’s the same as the upper end of the pipe, would you be able to see it from the top? Thanks, its a great idea, but there is enough of a turn in the stream so that the balloon would not be visible. [![](https://img.photobucket.com/albums/v61/GarySiegel/2014-05-15%2010.27.19_zpskqvvlu5v.jpg) ](https://img.photobucket.com/albums/v61/GarySiegel/2014-05-15%2010.27.19_zpskqvvlu5v.jpg) [![](https://img.photobucket.com/albums/v61/GarySiegel/2014-05-24%2013.16.17_zpstvmnhvdg.jpg) ](https://img.photobucket.com/albums/v61/GarySiegel/2014-05-24%2013.16.17_zpstvmnhvdg.jpg) [![](https://img.photobucket.com/albums/v61/GarySiegel/2014-05-17153542_zps70fbad56.jpg) ](https://img.photobucket.com/albums/v61/GarySiegel/2014-05-17153542_zps70fbad56.jpg) ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [March 5, 2015, 2:30am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/12 "2015-03-05T02:30:46Z")
> [@Mangosteen](#): > > Thanks, its a great idea, but there is enough of a turn in the stream so that the balloon would not be visible. > > [http://img.photobucket.com/albums/v61/GarySiegel/2014-05-15%2010.27.19\_zpskqvvlu5v.jpg](http://img.photobucket.com/albums/v61/GarySiegel/2014-05-15%2010.27.19_zpskqvvlu5v.jpg) > > [http://img.photobucket.com/albums/v61/GarySiegel/2014-05-24%2013.16.17\_zpstvmnhvdg.jpg](http://img.photobucket.com/albums/v61/GarySiegel/2014-05-24%2013.16.17_zpstvmnhvdg.jpg) > > [http://img.photobucket.com/albums/v61/GarySiegel/2014-05-17153542\_zps70fbad56.jpg](http://img.photobucket.com/albums/v61/GarySiegel/2014-05-17153542_zps70fbad56.jpg) based on those pics, if it’s not something you could suss out with the help of a fluid mechanics textbook, there’s probably not going to be “an app for that.” ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [March 5, 2015, 2:41am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/13 "2015-03-05T02:41:13Z")
> [@Mangosteen](#): > > I am installing a mini hydro electric system in the stream that runs along the property line to power my home. [ul] [li]Does the owner of the other property know about this?[/li][li]Is the water body regulated? If so, have you informed that agency of your intentions?[/li][li]Do you actually own or lease the water rights to do this?[/li][li]Does the water body contain any species that might be considered protected?[/li][/ul] ---
**Author:** ![newme](https://avatars.discourse-cdn.com/v4/letter/n/e0b2c6/32.png) [@newme](https://boards.straightdope.com/u/newme)\ **Post date:** [March 5, 2015, 2:59am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/14 "2015-03-05T02:59:08Z")
If the pipe is already in place, install a pressure gauge at the bottom of the pipe and close it off, fill the pipe with water at the top, and read the pressure. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [March 5, 2015, 3:06am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/15 "2015-03-05T03:06:06Z")
and is it navigable any time of the year would be another restriction in general, not here in particular… height difference from maps or GPS might be good enough. flow rate at the turbine. ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [March 5, 2015, 3:13am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/16 "2015-03-05T03:13:23Z")
Have you (assuming you’re in the US) looked at the USGS 7.5 minute quadrangle for where you are? Especially if it’s a somewhat newer map they tend to be pretty darn accurate. They’re usually 20 foot contour intervals, but even if you have to extrapolate between the contours a little you should be safely in the ballpark. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 4:40am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/17 "2015-03-05T04:40:19Z")
> [@Duckster](#): > > [ul] > [li]Does the owner of the other property know about this?[/li] > Yes, written permission. He says that if my system “works”, he’ll be putting one in himself. > > [li]Is the water body regulated? If so, have you informed that agency of your intentions?[/li] > Permits applied for and approved in writing. > > [li]Do you actually own or lease the water rights to do this?[/li] > Own. > > [li]Does the water body contain any species that might be considered protected?[/li] > According to the permit above, none. > [/ul] Anything else? ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 4:41am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/18 "2015-03-05T04:41:59Z")
> [@newme](#): > > If the pipe is already in place, install a pressure gauge at the bottom of the pipe and close it off, fill the pipe with water at the top, and read the pressure. I’ll try this and see what I get. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 4:50am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/19 "2015-03-05T04:50:24Z")
> [@GreasyJack](#): > > Have you (assuming you’re in the US) looked at the USGS 7.5 minute quadrangle for where you are? Especially if it’s a somewhat newer map they tend to be pretty darn accurate. They’re usually 20 foot contour intervals, but even if you have to extrapolate between the contours a little you should be safely in the ballpark. Thanks for the map, but its just not quite detailed enough. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [March 5, 2015, 4:56am UTC](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173/20 "2015-03-05T04:56:12Z")
> [@johnpost](#): > > and is it navigable any time of the year would be another restriction in general, not here in particular… > > height difference from maps or GPS might be good enough. flow rate at the turbine. Not navigable any time of the year. On any map I’ve seen, I really don’t know where I am. I see the nearby road, but I can’t tell exactly where the pipe starts in relationship with it. The length of the pipe is only 200 feet (give or take). [Next page](https://boards.straightdope.com/t/is-there-an-app-to-determine-the-head-of-a-stream/714173.md?page=2)