Rainwater Harvesting for Drylands and Beyond by Brad Lancaster

September 22, 2011

Watershed Maps Are Community Maps

by Brad Lancaster © 2011

A watershed is “that area of land, a bounded hydrological system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community.”
— John Wesley Powell

Political boundaries are arbitrary. Watershed boundaries are real.

Click here for John Wesley Powell’s 1890 map of the “Arid Region of the United States, showing Drainage Districts.”

Click here and here for different versions of the United Watersheds of America map.

What watershed, what naturally bounded community, do you live within?
Have you walked, run, biked, danced, kayaked it in a big rain?
Have you watched the water flow, its volume, its quality, its source, and its destination?

I recommend you do. You will better know the Place you live within. You will better know the community to which you are connected, and with which you could connect better still.

Below are examples of how some communities are encouraging the strengthening of this connection.

Excellent watershed maps are available for Oakland and Berkeley, CA, showing current and historic boundaries and conditions.

The even more-elaborate Mannahatta project shows us what Manhattan looked like in its natural state (in 1609) before the city was built.

Watershed Management Group, with TerraSystems Southwest, has made a some great Tucson Basin Watershed Maps.

You can use these resources to make signs that highlight your neighborhood’s or community’s watershed(s). Scroll to the bottom of the page to see the sign we made for my Dunbar/Spring neighborhood and its watersheds (and click on the link below it to download as a jpeg).

Santa Cruz County, in California, is one municipality that places watershed signs where roads cross over watershed boundaries/ridgelines.

This was a follow up to a watershed road-signage project in Sonoma County conceived of by Brock Dolman and the Water Institute, funded by the State Coastal Conservancy, and partnered with the Southern Sonoma RCD. Download the how-to guide: Creek Signs: Guide to Developing a Local Watershed and Creek Signage Program.

These efforts help show the flow, instead of obscuring it within drain pipes and other hidden infrastructure, so we can better celebrate the flow, and enhance it and the watershed by turning draining watersheds into harvesting-water catchments.

For more on how we can do this on our own sites and within our own neighborhoods, read Rainwater Harvesting for Drylands and Beyond, Volume 1 and Volume 2.

For images of examples you can also check out my Water Harvesting Image Galleries.

Also check out Brock Dolman’s excellent Basins of Relations booklet, and while you’re at it check out his wonderful Bioneers presentation. It is on YouTube in three parts: Part one, Part two, and Part three.


This 17″ x 16″ all-weather reflective aluminum sign was made for $42 at SignAge in Tucson. We provided the pdf image, they made the sign, and we’ll post it on the Dunbar/Spring community bulletin board on the southeast corner of 9th Ave and University Blvd.

Click to download the JPEG of this Dunbar/Spring Washes and Watersheds sign.

For maps of major watershed boundaries in North America, Europe, and the globe click here.

Check out Veins of America, watershed maps showing the vein-like network of rivers and streams in the continental 48 U.S. states.

3 Responses to “Watershed Maps Are Community Maps”

  1. Andy in Germany Says:

    Those are interesting projects. Being car free I’m very much aware of watersheds around me: following rivers can get me around hills.

    From our balcony we can see about 20km, and the horizion is the watershed between the Rhine and Danube. Water falling this side of the hills will end up in Rotterdam, Water falling the other side will flow through Romania to the Black sea.

  2. Mead Mier Says:

    This is great to see. Thanks for all the super resources and research!

    Although only Dunbar Spring has this great metal sign up so far (which is fun to look at when I ride my bike through the neighborhood), there is another resource I wanted to share that is all around town. The City of Tucson has marked their washes with signs stating their names at many of the crossings to increase familiarity. (info at http://cms3.tucsonaz.gov/stormwater/education/onlyrain ) Not quite the same as a map sign, which I would love to see at every path and trailhead, but very helpful none-the-less.

    Additionally, there is an INTERACTIVE ON-LINE MAP (YAY!) to viewing your watershed and washes in Tucson. You can also turn on layers such as where the wash signs are and the Only Rain In the Drain markers at storm drain inlets, which teach people that anything dumped down these drains leads directly to our fragile desert washes.

    I am inspired by the Oakland maps and would to see that provided in our community (like the bike maps). I hope to do that for the Tucson region through our Clean Water Starts With Me! campaign at Pima Association of Governments in the coming year. Historic references to flowing water and springs would be so informational in the desert where once had greater flows before changes in landuse and drought. http://www.PAGstorm.com

    Thanks again!

  3. Episode 13: Watershed Maps are Community Maps | Wading In The Water Says:

    […] Rainwater Harvesting for Drylands and Beyond, Watershed Maps are Community Maps  […]

Drops in a Bucket Blog

 »Read all blog posts...

Upcoming Events

Also see the full list of upcoming events.

Umbrella Newsletter

The Umbrella: Spring Equinox 2017

A catch-all of resources,
events, media, and more
from Brad Lancaster
Spring Equinox 2017
Around here we like to rhyme with the seasons whenever possible. In this case, that means welcoming the fast-approaching beginning of SPRING (the Vernal Equinox (in the northern hemisphere) is March 20 this year in Tucson, and marks one of only two […]

 »Read all newsletters...

Like what this website offers?

Donations are greatly appreciated as they enable us to continuously update this expansive resource and generate new content. Thanks!