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:


Another incarnation of Google Maps: The site takes preliminary police reports from several dozen participating jurisdictions and maps their locations and details. Here’s the report for Berkeley (Google defeats my feeble efforts to make a screenshot of one of their maps — hey, sounds like a weekend project). Anyway, it’s a useful display if your thinking about what the ne’er-do-wells are doing in your town (we recently had a couple of daylight stickups within a block of our place). The limitation right now is that so few localities are listed, maybe because relatively few offer readily usable data.

OK, so poking around, I see a reference to, which does essentially the same thing as the IncidentLog does elsewhere. ChicagoCrime has a new Google Maps gadget that essentially combines the routemaking feature on Gmaps Pedometer and the site’s crime database. The resulting tool lets you plot a route anywhere in the city, set the parameters for time and type of crime, then get a Google map showing all the bad stuff that happens along the path of your evening constitutional. When you reach a danger spot, you can break into a run, resulting in fitness and personal safety benefits, or at least a good sweat.


Even though I love Google Maps, I found a flaw in the service: For whatever reason, the maps don’t always show rivers. If you call up a map of the Quad Cities, no problem. The Mississsippi and Rock rivers are depicted in beautiful traditional mapper’s blue (if that’s not an actual color, it should be). Now check out Princeton, California, one of America’s favorite former ferry crossings; if you click on the satellite image of the view, though, the Sacramento River pops into view.

What gives? I have no idea. On the maps, the river just kind of disappears about 75 miles north of Sacramento for some reason.

But what I really wanted to point out was a pretty cool application built on Google maps, the Gmaps Pedometer, that lets you chart your walks — the app is really designed for urban hiking, because it relies on drawing straight lines from point to point — and calculates the distance you’ve covered. Here’s a picture of Wednesday’s rambles in a well-known western town. You could put it to the test in Chicago and Brooklyn, but maybe not in neighborhoods that didn’t exist a year ago.

Where We Were

The map jones never stays quiet for long, though my habit is really just an incidental one. In late March, I wrote something in passing about Google Maps and what I liked about them. Since then, Google has combined its maps with the database of aerial and satellite photographs I think it acquired when it bought a company called Keyhole. Now you can specify any location in the United States — maybe the world, but I haven’t tried that — and in addition to the traditional map, you can also see an aerial image that matches the maps frame precisely.

So one of my first impulses is to look up places I lived growing up — like 196 Monee Road, in Park Forest, where we lived from 1958 through 1966 (the house had great heating ducts for storing beer, but my brothers have to relate that story).

Here’s a map that shows 196 Monee Road (unfortunately, I can’t figure out how to display the Google map on this page — if indeed that’s possible for a mere Web mortal such as myself).

Here’s the corresponding aerial image.

And here’s an aerial that shows how to get from 196 Monee Road to the next house we lived in, on Oak Hill Drive, a mile away.

Google Maps

I’ve always liked online mapping services, especially for getting directions and checking distances between points. Until very recently, I most often used Yahoo! Maps. Probably out of force of habit more than anything else, since there’s not a lot of difference between Yahoo!’s product and that offered by one of the other leading sites, Mapquest. Also, Google has always returned Yahoo! and Mapquest results when you look up place names.

A couple of weeks ago, I noted that there was a third map listing: Google Maps. I took a look. There are a couple significant differences from the others: In appearance, Google appears to be trying to deliver a graphically more finished or tasteful look — clearer labeling and muted grays, blues, yellows and greens. But the big change is in functionality: Google, which is delivering map data from Navtech (the same company that supplies maps to Yahoo!), has implemented a “scrolling” map function. So when you want to take a look at something that’s outside the frame of the map you’re looking at, you hit an arrow and move the map up or down, left or right, instead of hitting a link — as you need to do on Yahoo!, Mapquest or other sites — and waiting for a new map to download. This is a huge advantage when you want to do something like trace a route and allows you to use the online map much the way you’re accustomed to usiing a paper one.

Where the mainstream online mapping sites are wanting is in providing contextual data. When you drill down to a certain level, especially outside urban areas, the mapping service turn roads into simple lines flung across blank landscapes. That’s true to a large extent with paper maps, too, of course; but one thing that comes with a paper map is a representation of how all the roads and towns relate to each other, even if there’s lots of blank space (take a look at maps of western Kansas or Nebraska). The ideal online map would combine some of the detail you find on topographic maps — like those available online at TopoZone — with the user-friendliness of Google Maps.

For now — well, I guess there’s plenty of cartographic stuff to noodle around with — and I’m sure there’s all sorts of stuff going on out there that I have no idea about.