2.5 Hydrologic Systems

The Department of Natural Resources? Public Waters Inventory identifies numerous basins within the Long Lake subwatershed under the jurisdiction of the DNR (see Figure 10).  These include seven lakes and the following major unnamed basins:

Table 3.  Public Waters in the Long Lake subwatershed.

Name and DNR ID #

Name and DNR ID #

Name and DNR ID #

Name and DNR ID #

Dickey's (27-161 W)

Unnamed (27-469 W)

Unnamed (27-511 W)

Unnamed (27-839 W)

Holy Name (27-158 P)

Unnamed (27-470 W)

Unnamed (27-512 W)

Unnamed (27-856 W)

Long (27-160 P)

Unnamed (27-471 W)

Unnamed (27-514 W)

Unnamed (27-858 W)

Lydiard (27-159 P)

Unnamed (27-472 W)

Unnamed (27-516 P)

Unnamed (27-859 W)

Mooney (27-134 P)

Unnamed (27-473 W)

Unnamed (27-829 W)

Unnamed (27-860 W)

Unnamed (also known as School) (27-151 W)

Unnamed (27-476 W)

Unnamed (27-832 W)

Unnamed (27-861 W)

Tanager (27-141 P)

Unnamed (27-477 W)

Unnamed (27-833 W)

Unnamed (27-862 W)

Wolsfeld (27-157 P)

Unnamed (27-478 W)

Unnamed (27-834 W)

Unnamed (Pond A) (27-864 W)

School (27-150 P)

Unnamed (27-479 W)

Unnamed (27-835 W)

Long Lake Creek

Unnamed (27-155 W)

Unnamed (27-508 W)

Unnamed (27-836 W)

Unnamed watercourse from Holy Name Lake to S26T118R23

Unnamed (27-466 W)

Unnamed (27-510 W)

Unnamed (27-837 W)

Unnamed watercourse from School Lake to Long Lake

Source: Minnesota DNR.  See Figure 10.

The HHPLS included detailed modeling of the current and 2020 hydraulic and hydrologic conditions in the subwatershed.  That modeling includes the following results for modeled locations (lakes, ponds, channels, and crossings) within the subwatershed (see Table 4):

  • Existing Normal Water Level;
  • Existing High Water Level, peak discharge, and peak velocity for the 1.5 year, 24-hour and 100-year, 24-hour events;
  • 2020 predicted HWL, peak discharge, and peak velocity for the 100-year, 24-hour event; and the
  • Existing High Water Level for the 100-year, 10-day snowmelt event.

Those detailed results are not reproduced here, but are incorporated by reference.  The HHPLS model predicted that development in the western subwatershed along the Highway 12 corridor by 2020 would likely increase runoff volume and peak rates from those subwatershed units.

There are several landlocked basins within the subwatershed, including Mooney Lake and Lydiard Lake.   There are numerous wetland pockets with no natural outlet. 

Table 4.  Modeled peak discharge from the Long Lake subwatershed (cfs).

Event

Existing

2020

Snowmelt

1.5 year, 24 hour

708.8

-

-

100 year, 24 hour

708.8

708.8

-

100-year, 10-day

-

-

413.7

Source:  2003 MCWD Hydrologic, Hydraulic, and Pollutant Loading Study (HHPLS)