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Kansas River Watershed

When most people think of the Kansas
River they think of the main river itself, beginning at the point where the Republican and Smoky Hill Rivers join in Junction City and ending at the point where the Kansas River joins the Missouri River in Kansas City. That is about 173 miles of river channel.

But the Kansas River Watershed includes all of the tributaries that flow into the main river; the Republican River, Smoky Hill, the Big Blue River, and many others flow into the Kansas River from throughout its watershed.

All told, the Kansas river drains an area of 36,000 square miles of land in Kansas  (almost the entire northern half of the state), 11,000 square miles in Nebraska, and 6,000 square miles in Colorado—53,000 square miles in all.

In turn, the Kansas River is itself a tributary of the Missouri River. The larger Missouri River Watershed, in which the Kansas River Watershed is nested, drains almost ten times as much land--523,000 square miles.

To complete the picture, the Missouri River is a tributary of the Mississippi River. The Mississippi River Watershed drains 1.83 million square miles! This is forty percent of the United States (not including Alaska and Hawaii). It is the second largest watershed in the world.*

So the Kansas River Watershed is nested within the Missouri River Watershed, and the Missouri River Watershed is nested within the Mississippi River Watershed, making all of us in northern Kansas part of a truly world class river system.

Here is an interactive map of the Kansas River watershed (outlined in green), which includes the Smoky Hill and Republican Rivers. You can zoom in and out and change to Satellite view to explore the watershed and see the location of towns, cities, rivers and reservoirs.  If you would like to view it in Google Earth click here

Google Map

So What is a Watershed?

No matter where you live in the world, you live in a "watershed." You're sitting in a watershed right now.

A watershed is bordered by higher ground, and since water runs downhill a watershed can be defined by the area of land that catches rain and snow and drains or seeps into a common point. Watersheds can drain into a marsh, stream, river, lake, ocean, or even into the groundwater. Homes, farms, ranches, forests, small towns, big cities and open land can all be part of watersheds. 

Some watersheds cut across county, state, and even international borders, and may be millions of acres in size. Smaller watersheds can be nested into larger watersheds, just as creeks drain into rivers, and rivers run to the ocean.

Watersheds within watersheds

The United States has been divided into a series of smaller and smaller watersheds, and each has been given a Hydrologic Unit Code (HUC). The HUC number can be thought of as something like a Zip Code for rivers. The HUC code is set up so that the large watersheds have a shorter code and the smaller watersheds have a longer code-- for example, the Kansas River watershed is a HUC 4 with the code number of 1027 (notice that there are four numbers in this code). Within this big watershed there is the Lower Kansas River watershed with a HUC 8 code number of 10270104 (this one has eight numbers within the code). So the smaller watershed is nested within the larger watershed and the HUC code for the smaller watershed contains the HUC code for the larger watershed: 1027 for the Kansas River and 10270104 for the smaller Lower Kansas River watershed that is nested within it.

The smaller HUC 8 watersheds that are part the Kansas River Watershed are the watersheds of its major tributaries:

HUC 10270101 - Upper Kansas
HUC 10270102 - Middle Kansas
HUC 10270103 - Delaware
HUC 10270104 - Lower Kansas
HUC 10270205 - Lower Big Blue
HUC 10270206 - Upper Little Blue

Google Map

These HUC 8 watersheds contain even smaller watersheds. For example, in Johnson County there are several creeks nested within the Lower Kansas Watershed: Captain Creek, Cedar Creek, Kill Creek, Mill Creek, and Turkey Creek. These are HUC 11 watersheds, which mean that they are smaller than the HUC 8 or the HUC 4 watersheds that they are part of. For example, Kill Creek has the HUC code 10270104150 (this starts with 1027 that means it is within the big Kansas River watershed, followed by 0104 that means its within the smaller Lower Kansas River watershed, and 150 that gives the "address" of the little Kill Creek watershed).

* From: The Mississippi River Basin, in The Water Encyclopedia