HomeMy WebLinkAboutCOW Agenda Item V 05/13/2008
Mount Prospect
Mount Prospect Public Works Department
INTEROFFICE MEMORANDUM
TO:
VILLAGE MANAGER MICHAEL E. JANONIS
FROM:
VILLAGE ENGIN EER
DATE:
MAY 7.2008
SUBJECT:
PRIVATE PROPERlY DRAINAGE ISSUES
Problem Statement
Every storm event triggers numerous calls from residents with private property drainage
issues. As a recent example, the August 2007 storm was typical. After that storm, the
Engineering Staff received 30 service requests about back yard flooding. Flooding which
in most cases does not cause damage to buildings, but does create a pool of water which
can stay in a back yard for days. Of these 30 calls, 17 were resolved through engineering
recommendations to relocate sump pump hoses and downspout locations. However, 13
needed further attention, including requests for designs and cost estimates to alleviate
standing water in their backyard. This winter and spring have been unusually wet and
have generated an additional 24 requests for help with drainage problems.
The Engineering Staff established a policy to assist residents with the resources we had
available, namely to analyze the problem, identify a solution and provide the design and
cost estimate for the residents at no cost. We provide free engineering services to the
residents, but the residents must pay for the improvements. The residents then are
instructed to obtain a permit for the work utilizing the Village prepared plan, hire a
contractor and have the work completed. The Village also provides financial assistance
with any work within the Village ROW. If the work involves any construction within
Village ROW, our policy has been to reimburse the resident for that portion of the cost
of the work within Village ROW. The resident is to present a copy of the paid bill to
Engineering for processing of the reimbursement.
The cumulative effect over the years has resulted in the preparation of 73 flood
protection plans by the Engineering Staff since 1997. Of those, only 5 have been
constructed. 54 are still pending resident action to move forward. From this winter and
spring, 14 properties are awaiting design plans and estimates. Typically projects are not
moved forward by the residents because of the cost. This is a significant expenditure of
time for the Engineering Staff which has provided engineering expertise to the residents
but has produced very little positive results in terms of flooding resolutions.
Residents often feel that it is not fair for them to absorb the burden for providing a
drainage solution for the entire block just because they are the lowest lying lot. In some
cases, the flooding is caused by code violations such as regrading in the rear yard
easement without a permit or by the construction of fences and sheds which restrict the
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Private Property Drainage Issues
May 7, 2008
flow across the drainage easement. However in most cases simply enforcing the code
will not alleviate the flooding problem. Typically the flooding is not caused by code
violations but is caused by a failure of the rear yard swales to function as they were
designed, leaving water trapped in one or more back yards. We are not blessed with a
great deal of elevation variation in Mount Prospect, so most yards are graded with
minimal slope. Over time the swales become filled with silt. And as a pocket of water
develops, the land begins to subside as this water carries the fine material from the dirt
lower into the ground. This pocket then becomes the back yard trap for rain water.
Reestablishing the rear yard swales would involve removal of fences, bushes and other
planting areas that obstruct the flow. However, this would only provide a temporary
solution at best until the bushes and fences have a negative impact again.
Typically the most effective rear yard drainage solution is comprised of some
combination of under-drain pipes, catch basins and a connection to the Village storm or
combined sewer systems in order to alleviate the flooding problem.
New Resource
In late 2006, the Village Board approved the collection of 'Fee in Lieu of Stormwater
Detention' for certain improvements which increased the impervious area and
stormwater runoff from a site, but that was too small to practically provide stormwater
detention. The Village began collecting this fee in January 2007. For the entire year of
2007, over $91,000 was collected. The Engineering Staff views this fee as a new
resource to combat rear yard drainage problems. Utilizing this money to pay for a larger
portion of the rear yard flooding solutions could be just the enticement that residents
need to move forward with construction of projects that would minimize recurring rear
yard flooding.
Eligible Locations
Because there is a long list of current locations desiring drainage improvements, staff
believes that projects should meet certain criteria to be eligible for expenditure of Village
funds. Staff considers the following criteria as a minimum:
* Water visibly remaining on the surface of the yard 48 hours after the end of a storm
event.
* Residents must agree to pay for the restoration of their yard after completion of the
construction.
* Residents must agree to maintain the improvements after construction.
Program Details
Similar to current procedures, the Engineering Staff will inspect all requests concerning
private property drainage problems and determine if a location meets the minimum
criteria for inclusion in the program. If it does staff will gather the necessary field
measurements and complete a design for drainage improvements. The project will then
be placed in line for construction when funds are available. The Village will pay for all
improvements except for the restoration of the private property. This will give the
resident the opportunity to have the work done by the contractor or to potentially
reduce cost by completing the restoration work themselves. The Village will hire a
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Private Property Drainage Issues
May 7. 2008
contractor to complete the work schedule for each year and inspect the work during
construction. Following construction. the residents will be responsible for future
maintenance and operation of the drainage system.
Village Staff will establish a priority ranking of the projects based on the seriousness and
extent of flooding at each location. Projects will be constructed on a worst first basis
according to that list. New projects will be evaluated and added to the list according to
their ranking.
A typical drainage project is estimated to cost approximately $15.000. It is anticipated
that roughly 6 projects can be completed per year at the current rate of fee in lieu
collection.
Design Features
Each project will be designed to provide an efficient system to drain stormwater away
from rear yards while minimizing the impact to the receiving sewer system. The smallest
practicable size restrictor will be installed in the drainage system to reduce the rate of
stormwater flowing into the Village's drainage system. This design will establish an outlet
for all trapped water in rear yards, but because of the restrictor, water may stay in the
backyards for a short period of time.
Des Plaines Experience
The City of Des Plaines instituted a similar program to address private property flooding
four years ago. Projects qualify if the flooding affects more than one property owner
and if the water stands in the yard for at least 24 hours. During that time they have
identified 300 locations that qualify for projects and have spent $2,000,000. The City
pays 1000/0 of the construction cost and the residents are required to sign an agreement
to maintain the improvements after construction. The City hopes to phase out the
program by next year with funding of $200,000 this year and $100,000 in 2009.
COW Meeting
It is intended to present this information to the Village Board at the May 13th COW
Meeting. Staff will prepare a PowerPoint presentation that will include pictures that
illustrate typical rear yard flooding conditions. Staff has also informed a few residents
who have flooding conditions in their yards that may want to come and share their
experiences. I am seeking comments from the Village Board concerning this program and
the utilization of the 'Fee in Lieu of Stormwater Detention' for this program. If you have
any questions, please feel free to contact me.
~~
Cc: Glen R. Andler. Public Works Director
H: Engineering\Drainage\PrivPropFloodingMm