What
are the problems?
The construction projects were designed to reduce flooding and sewer
back-ups in the Brookside Watershed Area of Kansas City, Missouri.
A questionnaire was sent to all of the properties in the area. The
following is a summary of some of the results to show the extent
of the problem:
- 64 percent (198/310)
responding to the survey reported flooding at their address during
the past 5 years.
- 19 percent (58/310)
responding reported over 6 inches of water entered their address.
- 10 reported
flooding explicitly because of sanitary sewage during dry weather.
- More than 30 percent (100/310)
reported flooding from sanitary sewage entering residence in
the past 5 years.
What causes the flooding?
The Brookside area was built in the post World War I era. Many streets
were built on or near creeks and named to reflect their location; for
example “Brookside.” Water flows naturally in a watershed to creeks
whether they have been built upon or remain natural. This is one reason
that the Brookside area experiences flooding.
The majority
of the existing public and private systems are very old and some
pipes have deteriorated. At several locations, pipes are collapsed,
and are full of debris and sedimentation. This reduces the carrying
capacity of the systems; meaning water cannot be carried away quickly
enough to avoid flooding. In addition, when these houses were built,
storm drains were considered a luxury item (similar to digital
cable of today), so the consensus was “undersized pipes are better
than no pipes."
In the early
1900s, engineering standards were different. The storm drainage
system constructed was not as large as those required by today’s
standards. Much of the development upstream was not considered
when designing the size of the system. The current storm drainage
system even when functioning properly is not adequately sized to
handle current and future conditions.
Will the improvement
program eliminate the chance of my property flooding?
The proposed public improvement program will NOT protect every
property in the Brookside area from flooding or sewage backing up
into basements. The only way to ensure that structures will not flood
in this area is to remove many of the structures. Due to the number
of structures and impact on the neighborhood, this is not a preferable
option. Rather than 100 percent protection, the community will attempt to
reduce the risk of flooding through public and private improvements.
The storm drainage
system in the Brookside area was designed to provide protection
for approximately the 2-year or 5-year storm event. (This is an
approximation because the concept of designing for a certain level
of protection wasn’t even practiced. Builders just installed storm
drains as large as they could afford or how big they thought they
should be). This means the system is designed to handle the size
storm that has a 20-50 percent statistical chance of happening every
year. (Note: many mistakenly think the 2-year storm means one that
happens every two years—not true.) The proposed system improvements
will be designed to increase the neighborhood’s protection against
flood damage. With the proposed improvements, the system should
adequately handle the size of storm event that has a 10 percent statistical
chance of occurring each year. The October 1998 storm was considered
to be at least a 100-year storm. This means that there is a 1 percent
statistical chance of that type of storm happening each year. Protecting
a community from the 100-year storm is a much higher level of protection
than what is planned (10-year storm). That means flooding will
probably still occur if this type of storm occurs. In an area such
as Brookside, it would be impossible to provide 100-year protection
without restoring the natural drainage paths. This would mean relocating
hundreds of homes, business, churches, and schools and converting
the area back to the natural flood plain. The City realizes the
social and economic impacts of relocating homes in Brookside does
not consider it a viable option.
What
causes the sanitary sewer back-ups?
The Brookside area was built in the post World War I era. The majority
of the existing public and private systems are very old and deteriorated.
Separate public storm drainage and sanitary sewer systems were built
in the southern portion of the watershed. Rather than hooking up
to the appropriate system, many builders hooked both the private
storm drainage and sanitary sewer lines up to the public sanitary
sewer system. The sanitary sewers were not designed to carry both
stormwater and sewage and this is why sewage back-ups occur into
many homes when it rains.
How
will the City’s planned public improvement projects reduce
flooding and sanitary sewer back-ups?
The approach to reducing flooding and sanitary sewage backups is
to increase the carrying capacity to allow more flow through the
system and to disconnect the storm drainage and sanitary sewers from
each other.
The City plans to increase the carrying capacity of the storm drainage
system by:
- replacing
deteriorated catch basins
- cleaning
existing catch basins
- replacing
existing old, undersized pipes with new larger pipes;
- lining
existing pipes
- installing
new pipes and leaving the existing ones in place so two parallel
storm drainage pipes will carry the stormwater runoff.
The
City plans to increase the carrying capacity of the sanitary sewer
system by:
- replacing
pipes with new larger pipes
- lining existing
pipes
- disconnecting
the publicly owned storm drainage and sanitary sewer system.
The City’s investment
in the public system will be important, but citizens’ investment
will also be needed to ensure that the entire system functions
properly.
What
can residents do to reduce flooding and sewage back-ups into
homes and buildings?
To achieve the neighborhood goals of reducing flooding and sewer
backups, residents will need to take action. At the same time the
City is making a substantial investment in improving the public systems,
citizens will need to make repairs and modifications to the system
on their property so the goals of the program can be achieved.
For both the storm drainage and sanitary sewer system, there are
portions that are publicly owned and there are portions that are
privately owned. The City is improving the publicly owned system
and citizens will need to make improvements to the portion of the
system they own and are responsible for in order for the systems
to function properly. The following are a few of the types of citizen
actions that are recommended:
Sewer Lines
Some
privately owned sewer lines are damaged or undersized. Citizens
are encouraged to clean, repair or enlarge sewer lines if needed
to improve carrying capacity to the publicly owned system. It is
recommended that citizens employ a licensed plumber to assist them
with these repairs.
Disconnect
Downspouts and Drains
The Brookside
area was developed in the post-World War I era. Separate public
storm drainage and sanitary sewer systems were built. Many builders
at that time connected the property’s downspouts and drains to
the sewer system rather than the storm drainage system. This
causes too much water to flow into the sanitary sewer lines causing
sewage to backup into homes and businesses. Because of the problems
connections cause, the City has made them illegal. Citizens should
disconnect drains and downspouts from the sanitary sewers even
if they have not experienced problems with backups. Your connections
may be the cause of sewage backups in your neighbor’s basement.
Citizens should check to see if they have downspouts or floor,
basement, driveway, stairwell or other stormwater drains connected
to sanitary sewer system. You can view examples of potential
improper private connections on the Typical
Private Sector figure. If a plumber is employed to assist
property owners, they should be licensed with the City. If the
downspout is disconnected, consider building a rain garden to
absorb and treat stormwater. Learn how at http://www.epa.gov/reg3esd1/garden/stormwater.htm
Backflow Preventers
Citizens
should install a backflow valve in the sewer line to reduce sewage
and septic back-ups. This backflow valve is opened by the flow
of sewage exiting the house but closes when the flow reverses,
preventing sewage from backing into the house. Even if property
owners have not experienced sewer back-ups, it may be advisable
to install backflow valves in this neighborhood. Backflow valves
or preventers should be installed by a licensed plumber. A city
building permit is required. To find out more about backflow preventers,
check out the Federal Emergency Management Agency (FEMA) website
at http://www.fema.gov/plan/prevent/howto/how2007.shtm
Other FEMA
Recommendations:
The Federal
Emergency Management Agency (FEMA) recommends a few other steps
citizens can take to mitigate the effects flooding.
Elevate or
relocate furnaces, hot water heaters, electrical panels and other
equipment as well as important personal items or property so
they won’t get damaged.
Buy and install
sump pumps with back-up power.
Don’t drive
through water in the street. It only takes two feet of water
to carry an automobile away.
Purchase government
subsidized flood insurance at a reduced rate. To find out more,
check out http://www.floodsmart.gov/floodsmart/pages/index.jsp.
“Six Ways to
Protect Your House from Flooding” is available at: http://www.fema.gov/rebuild/mat/rfit.shtm.
How will residents
be affected during construction?
The storm drainage and sanitary sewer system are located in citizen’s
yards and in the streets. Most of the publicly-owned lines located
in yards are within the city’s easement. This means while the pipe
system is located in your yard, the City has legal right to work
in the easement on publicly owned facilities. The City will also
be working in streets and which may mean limiting access to these
streets during construction. It is the goal of the City in designing
and building the public improvements to minimize the impact on citizens
during construction. Your cooperation and patience is appreciated.
Please click on “Alerts” to
find out more.
