Low Impact Development Manual for Michigan - OSEH - University ...

Maintenance
Local land conservancies are excellent resources when
considering the long-term stewardship of the area. If a
site has critical value, a local conservancy may be interested
in holding a conservation easement on the area, or
may be able to provide stewardship services and assistance.
The following organizations may also provide
resources:
• Stewardship Network (www.stewardshipnetwork.
org), a statewide organization, provides
informational and educational resources about
stewardship in Michigan
• Wild Ones (www.for-wild.org/) is a national
organization with local chapters which may also
provide stewardship resources.
Applying a carefully selected herbicide (Roundup or
similar glyphosate herbicide) around the protective
tree shelters/tubes may be necessary, reinforced by
selective cutting/manual removal, if necessary. This
initial maintenance routine is often necessary for the
first two to three years of growth and may be needed
for up to five years until tree growth and tree canopy
form, naturally inhibiting weed growth (once shading
is adequate, growth of invasives and other weeds will
be naturally prevented, and the woodland becomes selfmaintaining).
Survey the new woodland intermittently
to determine if replacement trees should be provided
(some modest rate of planting failure is usual).
Prairie management is somewhat more straightforward.
A seasonal mowing or burning may be required,
although care must be taken to make sure that any
management is coordinated with essential reseeding
and other important aspects of meadow reestablishment.
In addition, burning needs to be coordinated with
the local fire marshall and follow local regulations. In
the first year, weeds must be carefully controlled and
consistently mowed back to four to six inches tall when
they reach 12-18 inches in height.
In the second year, continue to monitor and mow weeds
and hand-treat perennial or rhizomatous weeds with
herbicide. Weeds should not be sprayed with herbicide
if the drift from the spray may kill large patches
of desirable plants, allowing weeds to move in to these
new open areas. If necessary, controlled spot herbicide
applications may be used to treat invasive plants if the
treatments can be completed without damage to offtarget
vegetation.
A prescribed burn should be conducted at the end of
the second or beginning of the third growing season.
If burning is not possible, the prairie should be mowed
very closely to the ground instead. If possible or practical,
the mowed material should be removed from the
site to expose the soil to the sun. This helps encourage
rapid soil warming which favors the establishment
of “warm season” plants over “cool season” weeds.
Long-term maintenance should incorporate burning or
mowing on a two to five year cycle to minimize woody
species growth while encouraging development of the
native prairie species.
Stormwater Functions and
Calculations
Volume and peak rate
Native revegetation will lower runoff volume and peak
rates by lowering the runoff coefficient (i.e., curve
number). Designers can receive credit based on the
square feet of trees or shrubs being added. Proposed
trees and shrubs to be planted under the requirements
of these BMPs can be assigned a curve number (CN)
reflecting a woodlot in “good” condition for an area of
200 square feet per tree or the estimated tree canopy,
whichever is greater. For shrubs, the area should be
25 square feet per shrub. Calculation methodology to
account for this BMP is provided in Chapter 9.
Example of savanna restoration
Source: JFNew
LID Manual for Michigan – Chapter 7 Page 237