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Drainage Design Criteria

Quiz Questions

1.____________ reviews and approves permits relating to developments requiring publicly maintained storm drain systems, connections of private drain systems to public systems, improvements to existing public storm drain facilities, and/or plan approval for subdivision development.
None of the above
2. Deep pipes are considered to be installed at depths ranging from 12 feet to 20 feet below ground elevation.
3.The ______________ is the period of time required for the storm water runoff to flow from the hydraulically most distant point, representative of the tributary area, to the point under consideration.
Time of Concentration (TC)
Storm of Concentration (SC)
Water of Concentration (WC)
None of the above
4.One of the most commonly used equations for the calculation of peak flow from small areas is the Rational formula, which is below. What does "i" represent in the formula?
Drainage Design Criteria
Peak Discharge
Correction factor
Units Conversion factor
Rainfall intensity
5.Inlets can be placed in cross walks or impede pedestrian movement.
6.Which of the following is not a type of loss that may exist within a storm drain system?
Inlet losses
Transition losses
Manhole losses
Piping losses
7.Any culvert with diameter over six feet is designated and reviewed as a bridge.
8. Assessment and mapping of which of the following natural resources are necessary in order to assist in properly locating a crossing?
Existing stream channel geometry
Width, depth, and velocity of the bankfull storm event.
Location of steep slopes
All of the above
9.___________ are alluvial channels formed through long term geomorphic activity including erosion and sedimentation.
Natural channels
Artificial channels
Biological channels
None of the above
10.The designer must be cognizant of the whether the proposed storm drains will impact any Federal or State waterways. A joint permit application must be submitted for any project that impacts which of the following?
100-year floodplain
All of the above
11.Ditches are considered integral components of the County drainage system. Ditch capacity shall be calculated using __________ formula.
12.A pre-formed scour pool is an excavated hole or depression that is lined with riprap of a stable size to prevent scour.
13.Which of the following Sump Pump discharges allowed?
Discharge to a roadside swale without curb
Discharge to a curb outlet or alternative discharge into right of way
Discharge to an existing County facility
All of the above
14.Generally, the _________ storm frequency shall be used in designing pavement drain systems.
15._____________ is the shallow mass of runoff on a planar surface with a uniform depth across the sloping surface. This usually occurs at the headwater of streams over relatively short distances, rarely more than about 300 ft (on paved lots), and likely less than 100 ft.
Sheet flow
Water flow
Slope flow
None of the above