Using GIS to estimate impervious surface area

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Impervious surfaces are typically artificial structures, such as
roads, sidewalks, driveways, etc… that are covered by in impenetrable
materials like asphalt, concrete, and rooftops. These surfaces can
become environmental concerns because they eliminate rainwater
infiltration and groundwater recharge, resulting in a significant impact
on flooding. The Village of Wheeling calculates the impervious surface
area for each parcel whenever there is a plan for new construction. If
any amount of new impervious surface area is planned, an equivalent
amount of water retention area has to be created. Typically, the
Village engineers would make these calculations by measuring the
impervious surface area using engineering drawings. This process can
take a significant amount of time and effort to get an accurate
measurement. The Engineering department requested that something be
created that would allow them to quickly get amount of impervious
surface for each lot in the Village.

To create an impervious surface area, existing base data such as
roads, driveways, sidewalks, and buildings were combined to form one
impervious surface area feature. This feature was then clipped by the
Village lot lines to separate the impervious surface area by each lot.
The amount of impervious and pervious surface area was then calculated
for each lot by comparing it to the overall square footage. By
combining all the data and then doing one mass calculation, the
engineering department does not have to spend time calculating each lot
by hand. By using GIS, the engineering department can reference the
calculations faster and with more accuracy.

Using GIS to estimate impervious surface area

Blog_UsingGIStoestimateimpervioussurfacearea.png

Impervious surfaces are typically artificial structures, such as
roads, sidewalks, driveways, etc… that are covered by in impenetrable
materials like asphalt, concrete, and rooftops. These surfaces can
become environmental concerns because they eliminate rainwater
infiltration and groundwater recharge, resulting in a significant impact
on flooding. The Village of Wheeling calculates the impervious surface
area for each parcel whenever there is a plan for new construction. If
any amount of new impervious surface area is planned, an equivalent
amount of water retention area has to be created. Typically, the
Village engineers would make these calculations by measuring the
impervious surface area using engineering drawings. This process can
take a significant amount of time and effort to get an accurate
measurement. The Engineering department requested that something be
created that would allow them to quickly get amount of impervious
surface for each lot in the Village.

To create an impervious surface area, existing base data such as
roads, driveways, sidewalks, and buildings were combined to form one
impervious surface area feature. This feature was then clipped by the
Village lot lines to separate the impervious surface area by each lot.
The amount of impervious and pervious surface area was then calculated
for each lot by comparing it to the overall square footage. By
combining all the data and then doing one mass calculation, the
engineering department does not have to spend time calculating each lot
by hand. By using GIS, the engineering department can reference the
calculations faster and with more accuracy.

Creating hospital mapbooks with GIS

Blog_CreatinghospitalmapbookswithGIS.png

The ambulances for the Village of Wheeling Fire Department can take
patients to approximately 30 hospitals in the Chicago-land area.
Because some of the hospitals are frequented less and are many miles
outside the Village limits, each ambulance contains a book of maps
detailing the location of each hospital. The maps are simple location
maps made from data over 10 years old. The Fire Department requested
that the maps be modified and updated to reflect current data.

A new map book was created with each page of the book representing a
different hospital. The street data was updated and the page was
divided into two separate maps: a large map showing the location of the
hospital and a smaller map showing its location in relation to the
surrounding communities. By having the maps in each ambulance, the
paramedics are able to easily locate hospitals that they are not
familiar with, and make sure they arrive at their destination.

Creating hospital mapbooks with GIS

Blog_CreatinghospitalmapbookswithGIS.png

The ambulances for the Village of Wheeling Fire Department can take
patients to approximately 30 hospitals in the Chicago-land area.
Because some of the hospitals are frequented less and are many miles
outside the Village limits, each ambulance contains a book of maps
detailing the location of each hospital. The maps are simple location
maps made from data over 10 years old. The Fire Department requested
that the maps be modified and updated to reflect current data.

A new map book was created with each page of the book representing a
different hospital. The street data was updated and the page was
divided into two separate maps: a large map showing the location of the
hospital and a smaller map showing its location in relation to the
surrounding communities. By having the maps in each ambulance, the
paramedics are able to easily locate hospitals that they are not
familiar with, and make sure they arrive at their destination.

CRS Review Drainage Maintenance

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After the Village of Wheeling had its scheduled review for the CRS
program (A review of the Village’s flood safety infrastructure), the
independent reviewer left a list of items that needed to be completed in
the next month to receive credit in specific categories. One of these
items pertained to storm system drainage, specifically the locations of
known problem areas in the storm drainage system and which features,
such as ditches and streams that the village maintains. The engineering
department asked the GIS department to put something together that
would meet all the requirements and could be submitted to the reviewer.

For the submission, a map was created showing the water features that
the village maintains, as well as locations of drainage trouble areas
designated by the village. Without GIS, the village would have had to
create the map in a different program, such as AutoCAD, due to new
regulations specifying that all maps submitted to the CRS review have to
be done in a computer program. By using GIS, the village was able to
submit a required document in the short amount of time required.

CRS Review Drainage Maintenance

Blog_CRSReviewDrainageMaintenance.jpg

After the Village of Wheeling had its scheduled review for the CRS
program (A review of the Village’s flood safety infrastructure), the
independent reviewer left a list of items that needed to be completed in
the next month to receive credit in specific categories. One of these
items pertained to storm system drainage, specifically the locations of
known problem areas in the storm drainage system and which features,
such as ditches and streams that the village maintains. The engineering
department asked the GIS department to put something together that
would meet all the requirements and could be submitted to the reviewer.

For the submission, a map was created showing the water features that
the village maintains, as well as locations of drainage trouble areas
designated by the village. Without GIS, the village would have had to
create the map in a different program, such as AutoCAD, due to new
regulations specifying that all maps submitted to the CRS review have to
be done in a computer program. By using GIS, the village was able to
submit a required document in the short amount of time required.

Verifying sales tax information using GIS

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Every year, The Village of Wheeling finance department receives tax
information from the State. This information includes the amount of
money the village received from sales tax and which companies provided
it. In previous years, the finance department would look over the data
and try to find any discrepancies in the data and see if they were
missing sales tax from companies in the Village. They would typically do
this by comparing the sales tax information with the business license
data by hand. This year, the Village wanted to do a more thorough check
and one that wasn’t as time consuming, so they decided to compare the
two tables by using GIS.

Because both the sales tax information and the business license
tables contained address information, the data was easily mapped using
the Village’s address database. With both tables mapped, checks were run
to determine which business license records did not have a sales tax
record, and which sales tax records did not match any existing business
license. This process would help find any businesses that Wheeling did
not receive sales tax from and additionally businesses that did not have
an existing business license.

The finance department received full lists of businesses within the
Village that they did not receive sales tax from and businesses that
were listed in the sales tax table that did not have a business license.
There are many possible reasons why both situations exist, but by
having a list the finance department was able to go to the state and
figure out each record discrepancy. By using GIS, the finance department
was able to expand on an already existing project and save some time in
the process.

Verifying sales tax information using GIS

Blog_Verifyingsalestax.png

Every year, The Village of Wheeling finance department receives tax
information from the State. This information includes the amount of
money the village received from sales tax and which companies provided
it. In previous years, the finance department would look over the data
and try to find any discrepancies in the data and see if they were
missing sales tax from companies in the Village. They would typically do
this by comparing the sales tax information with the business license
data by hand. This year, the Village wanted to do a more thorough check
and one that wasn’t as time consuming, so they decided to compare the
two tables by using GIS.

Because both the sales tax information and the business license
tables contained address information, the data was easily mapped using
the Village’s address database. With both tables mapped, checks were run
to determine which business license records did not have a sales tax
record, and which sales tax records did not match any existing business
license. This process would help find any businesses that Wheeling did
not receive sales tax from and additionally businesses that did not have
an existing business license.

The finance department received full lists of businesses within the
Village that they did not receive sales tax from and businesses that
were listed in the sales tax table that did not have a business license.
There are many possible reasons why both situations exist, but by
having a list the finance department was able to go to the state and
figure out each record discrepancy. By using GIS, the finance department
was able to expand on an already existing project and save some time in
the process.

Tracking benchmark locations

Blog_Trackingbenchmarklocations.png

The Village of Wheeling is currently preparing for the National Flood
Insurance Program Community Rating System (CRS) review. The review
takes into account various aspects of flood prevention infrastructure in
the village and ultimately decides the percentage of savings a resident
receives for flood insurance. One of the important aspects of the
review is a village’s maintenance of a network of surveying benchmarks.
By having a system of maintained benchmarks, surveyors are able to
locate them and depend on their accuracy, while the village receives a
higher score.

For the village to receive credit for Benchmark Maintenance, it must
meet a list of requirements: It must be in the National Spatial
Reference System (NSRS) database or be a permanent monument with key
data readily available to surveyors, such as the village website. There
must be a note that it’s been recovered in the past 5 years and it must
be a first or second order vertical control benchmark. Finally, each
benchmark but have a stability rating of A or B and be within 1 mile of
the community’s regulatory floodplain. In addition to the benchmarks
meeting these requirements, proper documentation is needed, which
includes a map showing the location of each benchmark.

By creating the map documentation for benchmark maintenance in GIS,
the village was able to satisfy multiple requirements with one product. A
series of small maps were created, each representing one of the
benchmarks in the village. In addition, a large overview map was created
showing the location of each benchmark at a large scale. The overview
map was added to the village website, and when a surveyor clicks on a
benchmark on the map, a PDF opens up with the smaller map representing
the information for that specific benchmark. By having this map located
on the village website, it meets the requirements of having it
accessible to surveyors and the public as well as being a document of
each benchmark’s location. By using GIS, the engineering department was
able to create a product that met CRS requirements and was accessible to
the public.

Tracking benchmark locations

Blog_Trackingbenchmarklocations.png

The Village of Wheeling is currently preparing for the National Flood
Insurance Program Community Rating System (CRS) review. The review
takes into account various aspects of flood prevention infrastructure in
the village and ultimately decides the percentage of savings a resident
receives for flood insurance. One of the important aspects of the
review is a village’s maintenance of a network of surveying benchmarks.
By having a system of maintained benchmarks, surveyors are able to
locate them and depend on their accuracy, while the village receives a
higher score.

For the village to receive credit for Benchmark Maintenance, it must
meet a list of requirements: It must be in the National Spatial
Reference System (NSRS) database or be a permanent monument with key
data readily available to surveyors, such as the village website. There
must be a note that it’s been recovered in the past 5 years and it must
be a first or second order vertical control benchmark. Finally, each
benchmark but have a stability rating of A or B and be within 1 mile of
the community’s regulatory floodplain. In addition to the benchmarks
meeting these requirements, proper documentation is needed, which
includes a map showing the location of each benchmark.

By creating the map documentation for benchmark maintenance in GIS,
the village was able to satisfy multiple requirements with one product. A
series of small maps were created, each representing one of the
benchmarks in the village. In addition, a large overview map was created
showing the location of each benchmark at a large scale. The overview
map was added to the village website, and when a surveyor clicks on a
benchmark on the map, a PDF opens up with the smaller map representing
the information for that specific benchmark. By having this map located
on the village website, it meets the requirements of having it
accessible to surveyors and the public as well as being a document of
each benchmark’s location. By using GIS, the engineering department was
able to create a product that met CRS requirements and was accessible to
the public.