Milfoil, and maps of where to expect it

It's a fact of life, both Lake Harriet and Lake Calhoun are plagued by Eurasian Milfoil. This non-native water plant was brought to the lakes on the propellers of powerboats. Once it hits a lake, there is little to do except try and control it by mechanical harvesting. It is a slow and costly process.

Milfoil grows into a thick clumpy mat, and depending on your keel and rudder configuration, sailing into it can range from a nuisance to a danger. But where might you find it? Well, the key is that the Milfoil seeds need sunlight to sprout, so on Minneapolis lakes, that means less than 10 feet of water. For everyone's benefit, I have created two maps that show the problem areas. See them after the break:

On the maps, the light blue areas represent water less than 10 feet deep, where Milfoil CAN in theory grow. It is not intended to state that all the blue areas will contain milfoil. But they could. Also, the weed takes time to grow each year, so the problem will not really start until late June.

Here is the Lake Harriet map . You can click on it to make it full size.  The only real problem area is on the east side of the lake. Because the water is consistently deep everywhere else, including the buoy field, you are unlikely to be surprised by Milfoil.

And now Lake Calhoun. You can see Calhoun has more shallow water, and more problematically, it is scattered about the lake. Be careful!

The city of Minneapolis cuts the Milfoil on a regular basis, but is can never be expected to get it all, or even keep up. As you sail on your lake, you get a better feel for where it is. Night sailing could be a challenge, however!