California Water Geek-Out, Maps Edition

A couple years ago, I made up what I don’t mind saying is a pretty cool Google Maps map outlining where the proceeds of a planned $11 billion California water bond would go (here’s the link). Not to shortchange the amazing capacity of Google Maps, but once you’d played with them for awhile you want to do more. And if you’re adept with code, you can muck around and do something more sophisticated with Google Maps. I am not allergic or adverse to code, but neither am I adept and it would probably take me a while to learn even the basics. But I am impatient and want to find a shortcut.

So, searching around for online mapping tools today, I happened across the National Atlas. There is no such thing as a map that’s not cool (or at least interesting in some way), but the site and basic outline map on the Map Maker page are a little plain vanilla. But then I started to play with it a little: I drilled in on California, then selected some data layers–highways, lakes and rivers, average precipitation. OK–the result was both useful, if I had a use for it, and kind of pretty (precipitation data will do that every time). Then I saw a layer for dams, and added that. Instantaneously, I had a view of the region that both answered and provoked my curiosity (there are at least 1,200 dams under state jurisdiction here–meaning they’re at least 25 feet or store at least 50 acre feet of water). That is a lot of dams, and when you click on individual structures on the map, you realize how few of them you know anything about. I can’t find a way to embed the map here, but here’s the link. Below is a screen shot (click for larger version); every inverted triangle is a dam.


Another layer you could add to the map: A grid that depicts an index of aerial maps. I superimposed the grid to take a look at an aerial photograph of the area of Lake Berryessa, the large elongated body of water at lower center, just west of Interstate 505. The lake (the state’s seventh largest reservoir, with a capacity of 1.6 million acre feet) is formed by Monticello Dam, which impounds a stream called Putah Creek about seven miles as the crow flies west of the town of Winters. I know the dam and the road that passes it from many bike rides from Davis, and one outstanding feature of the little visitors area at the top of the dam is the Glory Hole. It’s a circular intake for the reservoir’s spillway, which empties into Putah Creek.

So, once I found the aerial image (you need to superimpose the aerial photograph grid from the map layers, click on the “Identify” tab above the map, then click again on the spot you want to take a look at; the link to the image is in the “Identify” pop-up window; and as I write this I see how complicated it might seem to the ordinary user), I drilled down to Monticello Dam. Here’s the image (click for a larger version):


See that round thing to the left of the lower edge of the dam? That’s the Glory Hole. What’s remarkable here is that it’s high and dry. It does not overflow every year, but here it looks like it’s unusually exposed. It turns out the picture is dated June 16, 1993, and though the reservoir level had bounced back from the effects of a string of dry years that had shrunk it to just a third of capacity in 1991 and 1992, on this date the lake was little more than half full.

For a contrast, here’s a New Age-y slideshow on the Glory Hole in wet and dry times:


longbeach090310.jpg (Above: Looking south down the Los Angeles River, center, and across the junction of Interstate 405, the San Diego Freeway (running right and left) and Interstate 710, the Long Beach Freeway (which runs down the river’s western bank). Long Beach Harbor is in the distance. Taken just after takeoff from Long Beach Airport, September 3, 2010. Google map link.)

I took a long bike ride once from near Boulder, at the foot of the Colorado Rockies, to east central Kansas, then turned around and came most of the way back. The route was given not in a map but in a sort of schematic of the roads on the route. That was a simple matter because a good 80 percent of the route seemed to be on a single highway, U.S. 36. There was a point marked on the diagram about 80 miles or so southeast of Boulder–the point where the Rockies vanished as you headed east across the Plains and reappeared on the westbound route.

That mark on the map made an impression: I loved the idea of a point on the landscape where such a dramatic change is made visible. Most long-distance travel, especially between the Rockies and the Appalachians, I think, is a tale of subtle changes, watching landscapes shift slowly as you gain or lose elevation or encounter wetter or dryer climatic zones. It’s much different from traveling north or south, east or west across California, where the next amazing transformation seems always to be around the next bend.

And then there’s flying across country–by which I mean commercial airline flight–which compresses experience and landforms into an extended narrative of geographic changes. I’ve often fantasized about coming up with some manual or device that would serve as a guide to what the airline passenger sees as he or she soars overhead. At first I envisioned it as a fold-out book in which each page would show landmarks, landforms and highways all the way along the air route, and now I imagine that GPS and map software can hand you a continuous unfolding picture with as much detail as you desire.

The strip of landscape that rolls out beneath the main air routes between the Bay Area and Chicago has become familiar, but it’s still exciting to see from the air: the cityscape, the bay, the bridges, the islands, the towns, the freeways, the hills and mountains that slide beneath you as you head out into the Central Valley. The Sacramento-San Joaquin Delta with its knot of waterways, the farm geometry of the valley floor, the big valley cities. Then the foothills and big reservoirs and forests as the hills turn into mountains and the checkerboard of raw-looking clearcuts. Then granite and almost before you know it you’ve vaulted the crest of the Sierra Nevada, maybe within view of Yosemite or Lake Tahoe–so much of what you see depends on what side of the fuselage you gaze from.

Then Nevada: basin and range and uncountable debris fans at the foot of mountains and dried-up courses of old floods. You might be able to place yourself by the appearance of a road–Interstate 80, maybe, or the thin ribbon of U.S. 50, or one of the north-south routes. Then maybe you get a look across one of the mountain ranges at the Great Salt Desert, signaling Utah. Maybe you see that lake, or the Wasatch Mountains rearing up from the middle of the city. The Rockies may appear, or coral-painted canyonlands, or the course of the Green River or the Colorado.

By this time you might be an hour and a half into the flight, maybe more. If you’re connecting at Denver, you might sweep down to the plains across Rocky Mountain National Park. If you’re on a non-stop, you might or might not ever see a square inch of Colorado, but you’ll see some part of the mountain chain. When that’s over, you’ll see the dry, sparsely roaded High Plains. You might meet up with Interstate 80 again near the course of the North Platte River, a rough guide to the old pioneer routes. In western Nebraska the country looks hilly and potholed. Anywhere in these dry plains you might see broad circles of wheat or alfalfa irrigated straight out of the Ogalalla Aquifer. Slowly, the roads increase and the green becomes more intense. You might see Omaha; even if you don’t, you’ll see the Missouri River below, running across a floodplain marked by tall bluffs.

After that, you’re almost home. Iowa, farmed and fertile looking and looking anything but flat, a rolling landscape broken by hundreds of small and big streams. The Mississippi is ahead, impossibly wide and complex looking as it braids among heavily wooded islands. And then it’s southwest Wisconsin or northwest Illinois, with county roads knocked askew from the preferred township grid as they straggle across thousands of square miles of glacial debris dumped in the last ice age. And then towns: Madison in the distance, Janesville, Beloit, Rockford. The Rock River. The Fox River, the suburbs, the city, the airport. Touchdown.

(Flying out here Friday, my routine was interrupted. I flew down to Long Beach, then from there to Chicago. Terra incognita, mostly, especially sitting over the plane’s port wing. But I did get glimpses. I puzzled over our route after leaving Long Beach; we took off to the northwest, then turned and flew south out over the ocean before turning to head east, and I just don’t know the landscape down there. The first good reference point I spotted was crossing the Colorado River. And after that, just a lot of guesswork. (The actual flight path appears to be here.)