DESIGN SUMMARY TABLES
FOR
EROSION AND SEDIMENT CONTROL AND STORMWATER MANAGEMENT PLAN
REVIEWS
CVESCC
Definition: Design Summary Table - a standardized table which summarizes design parameters
and resulting construction parameters for a variety of Erosion & Sediment
Control (ESC) and Stormwater Management (SWM) features.
Central Virginia Erosion and
Sediment Control Committee - The CVESCC
consists of Erosion and Sediment Control Managers, Plan Reviewers, and
Inspectors from
The
committee has developed a series of standardized tables to summarize design
parameters and construction parameters for a variety of Erosion and Sediment
Control and Stormwater Management features frequently found on plans. Since basic design parameters are often
missing, or are lost in a series of difficult to understand calculations, and some
of the construction parameters required to build these features are frequently
missing from plan sheets, we as a group have decided to standardize and
simplify how we will require this information is to be presented. This should assist both the review and
construction processes.
Design Summary Tables - Design Summary Tables will be required on any submitted
plan sheet which includes any of the following features:
Stormwater Feature Alpha Identifier
Temporary
Temporary Slope Drain TSD
Stormwater Conveyance
Channel SCC
Outlet Protection OP
Rip Rap RR
Rock Check Dam CD
Level Spreader LS
Temporary Vehicular
Stream
Utility Stream
Crossing USC
Dewatering Structure DS
Stormwater Drainage
Pipe P
Drainage Area DA
The
CVESCC standard Design Summary Table for each of these features will consist of
the list of required parameters in the first column, and one additional column
for each occurrence of that type feature found on the plans. The list of required parameters for each of
these features is found on the attached list.
Each
occurrence of the feature must be labeled on the plan with a unique
identifier. The identifier will consist
of a standard alpha identifier followed by a dash followed by a numeric counter
(no spaces). In many cases the alpha
identifier will be the standard identification for E&S features as
specified by the Virginia Department of Conservation and Recreation in the
Virginia Erosion and Sediment Control Handbook.
For
example if a plan set includes four instances of outlet protection, these
occurrences shall be identified on the plan drawing as OP-1, OP-2, OP-3 and
OP-4. These identifiers should be
located inside the standard circle used for ESC features. Since the addition of a numeric counter will
create a longer identifier, an oval or ellipse may be more appropriate than a
circle. On the plan sheet a table will
be required listing the design and construction parameters for Outlet
Protection features in the first column followed by four columns indicating the
respective value for each parameter.
Sample Table
Format
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OUTLET PROTECTION SUMMARY TABLE |
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ID |
OP-1 |
OP-2 |
OP-3 |
OP-4 |
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DESIGN FLOW * |
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TAILWATER DEPTH |
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DISCHARGE VELOCITY |
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RIP RAP GRADATION |
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APRON LENGTH |
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APRON WIDTH(S) |
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SIDE SLOPES |
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APRON
DEPTH |
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This
example table will help the plan reviewer quickly know what design parameters were
used for sizing the outlet protection and quickly supply the contractor with
the required size information for construction which has been frequently
missing from submitted drawings.
Be
sure to include units for all entries either within each individual cell or
noted in the first column along with the parameter name.
Each
feature which requires a ‘design flow’ in its summary table must also have an
entry in the Flow Summary Table.
Flow Summary Table
Many
of the features to be summarized in the Design Summary Tables require a ‘design
flow’ to be properly sized. Since the
design flow itself also requires a series of input parameters in order to be
calculated, all of the basic information such as drainage area, runoff factor,
time of concentration, etc. could also have logically been included in many of
the Design Summary Tables. Instead
however, the committee has elected to not require this information in the
individual feature tables but to combine all of these parameters into a single
Flow Summary Table and require only the resulting ‘design flow’ to be
transferred into the individual feature table.
This allows the reviewer to quickly and easily compare the design flow
calculations for all types of features in a single location.
Thus,
along with the above sample there would also need to be at least four columns
in the Flow Summary Table indicating the input parameters for the four Outlet
Protection features. See below.
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FLOW SUMMARY TABLE |
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FEATURE ID |
OP-1 |
OP-2 |
OP-3 |
OP-4 |
etc. |
etc. |
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DESIGN EVENT FREQUENCY |
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RAINFALL INTENSITY |
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POST DEVELOPMENT |
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DRAINAGE AREA ID(S) |
DA-1 |
DA-2+3 |
DA-4+5+6 |
DA-7 |
DA-8+9 |
DA-10+11+12 |
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TOTAL DRAINAGE AREA SIZE |
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TIME OF CONCENTRATION |
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COMPOSITE RUNOFF FACTOR |
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DESIGN FLOW |
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PRE DEVELOPMENT (if needed) |
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DRAINAGE AREA ID |
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TOTAL DRAINAGE AREA SIZE |
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TIME OF CONCENTRATION |
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COMPOSITE RUNOFF FACTOR |
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DESIGN
FLOW |
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Drainage Area Map - A Drainage Area Map should be included in each ESC Plan
set. To prevent clutter, it may often
need to be a separate sheet, probably at the same scale as the site plan. The Drainage Area Map should delineate the
drainage area to each ESC and SWM feature for which the design requires a
drainage area. Be sure to show all
off-site drainage areas on the Drainage Area Map.
Frequently
the various ESC and SWM features will have drainage areas which are subsets of
one another. To prevent confusion, the
labeling of drainage areas should not involve overlapping areas. Each individually delineated area should be
labeled with its own ID and its own associated area in acres. Whenever cumulative drainage areas to certain
features occur, these drainage areas will be expressed as sums of the smaller
areas.
For
example a system of three inlets, three consecutive pipes, and outlet
protection at the end might have pipe P-1 with drainage area DA-1, pipe P-2
with drainage area of DA-1+2, pipe P-3 with drainage area DA-1+2+3, and outlet
protection OP-3 with drainage area DA-1+2+3.
Each
entry in the Design Flow Summary table must correspond with a defined and
labeled drainage area or a combination of drainage areas on the Drainage Area
Map.
ESC Narrative - Virginia Erosion and Sediment Control regulations require
an ESC Narrative to be included with each ESC Plan. Such narratives have been found both printed on
the plan documents or included with the plan documents as a separate 8-1/2 by
11 inch package. Due to the difficulty
in keeping separate smaller documents associated with larger plan documents the
CVESCC has elected to require that all ESC Narratives be included on the plan
documents.
Computer Outputs and Hand
Calculation Sheets - For many of
the simpler design calculations, the Design Summary Tables will reduce or
eliminate the need to include calculation packages with design plan
submittals. However in more complex
cases such as computer calculations for integrated pipe networks, submittal of
separate calculation packages will still be required. Be sure each
calculation sheet is labeled to reference the appropriate occurrence of the
plan feature. For example, make sure that
computer routing outputs for DB-1 are clearly labeled and distinguished from
calculations for DB-2, or that pipes in an integrated network are labeled with
the same identifiers in both the calculations and on the plans.