STORM TEST 3 QUESTIONS AND ANSWERS LATEST UPDATE 2025-2026
true or false: urban growth trees were found to typically have larger and more effective canopies
for intercepting rainfall than forest grown trees - Answers true
which type of tree - deciduous or evergreen - was shown to be more effective at rainfall
interception regardless of region? - Answers evergreen
in which region - southeast of pacific northwest - was a higher percentage of precipitation
captured by tree canopies? - Answers pacific northwest
if you were calculating runoff using the rational formula, which variable (C,I, or A) would best
describe the impact of tree canopies on runoff based on the article "Give Me the Numbers"? -
Answers I
What does LID stand for? - Answers low impact development
What two major components make up the Lh for a watershed? - Answers overland flow and
channel flow
In the storm water runoff hydrograph, the point at the top of the curve (N) represents: - Answers
peak runoff rate and time of peak
the shaded area beneath the curve on the hydrograph represents: - Answers Qvol
The two portions of this stream hydrograph identified at top and bottom of curves repectively: -
Answers base flow; storm flow
true or false: infiltration is the primary hydrologic process supporting stream base flow -
Answers true
true or false: runoff on a slop typically flows downhill perpendicular to the contours - Answers
true
true or false: the rational formula is most appropriate for use in relatively small watersheds
because inherent model error becomes excessive as the watershed are gets larger - Answers
true
determining Qvol is an essential hydrologic modeling practice because it allows the designer to:
- Answers size storage areas appropriately
why did teague and kuehler's research show that trees in the NW capture and retain more
rainfall than trees in the SE? - Answers rainfall events in the NW are less intense than in SE
a slope of 6% is equivalent to a ratio of: - Answers 16.67H:1V
a depression pond is proposed. what is the mose correct point for the at-grade overflow? -
,Answers the lowest point within the water limits
in the article "Give Me the Numbers", when comparing comparably sized trees, what kinds of
trees were most effective at capturing and retaining rainfall volume in the canopy? - Answers
conifers
true or false: creating an impervious area on a site will typically increase both Qp and Qvol. -
Answers false
along the centerline of a gradually descending roadway, the 426 contour is 135' away from the
420 contour. the gradient of the road is: - Answers D=L/G
G=L/D
G= 6/135
G=.044 = 4.44%
true or false: the faster the time of concentration, the lower the intensity. - Answers false
true or false: Teague and Kuehler's research found that the typical forest frown tree most
commonly has a more effective canopy for rainwater capture than the typical urban tree -
Answers false
a co-worker of yours calculated before-development and after-development site stormwater
runoff using the rational formula and also SCS method for an 18-acre watershed. he carefully
followed the procedures you have learned. based on the results, which finding is most correct? -
Answers both are equally correct even with different results
the LH for a watershed includes 1,800 feet of a mountain stream. if the channel drops 20 feet
over that distance, approximately how long will it take water to travel that distance (rounding to
the nearest minute) - Answers 14 mins - use figure 11.4 (nomograph for channel flow time)
true or false: given equal lengths and slope of flow, overland flow is typically faster than channel
flow - Answers false
both the FAA formula for calculating the time of concentration and the SCS method for
calculating the time of concentration rely on what criticl information? - Answers slope, land
surface characteristics, LH length
a reasonable minimum slop for reliable draining turf area is: - Answers 2%
a map is drawn at 1:24,000. which side of a standard engineering scale should you measure it
with? - Answers 1 inch = 24000 in
1 inch = 24000/12
, 1 inch = 2000 ft
20 scale
the modified rational formula "improves" the rational formula by accounting for: - Answers
antecedent precipitation
which topographic form (swale, ridge, constant) is most likely to exhibit the longest sheet flow
condition? - Answers ridge
when designing a development on a site which currently is undeveloped, and modeling runoff
using the SCS method, keeping the first portion of the LH in its existing condition is important
because: - Answers sheet flow accounts for more travel time than shallow concentrated flow &
maintaining a longer time of concentration will minimize increase runoff due to development
the Tc for an Athens, GA watershed is 34.3 minutes. what is the intensity (in/hr) for the 50 year
event in the watershed? - Answers use table provided
when applying the modified rational formula, why must adjusted C values must not exceed 1.0?
- Answers it represents a percentage of runoff and you cant have over 100%
true or fall: given equal slope and soil conditions, good dense forest usually generates less
runoff than good dense turf grass. - Answers true
based on the following watershed information, what is the peak rate of runoff? - Answers Qp=
CIA
=.37(34.23)(4.49)
=56.87
true or false: based on our class discussions, Qd is understod to be the runoff depth. - Answers
true
true or false: when comparing watersheds in the same geographic setting using the SCS
method, the major factor influencing Qvol is CN - Answers true
a storm event is calculated to produce 1.00 acre-feet of runoff from a 4.7 acre watershed. what
is the equivalent volume in cubic feet? - Answers 43,560 CF
which of the following stormwater management practices controls both Qp and Qvol? - Answers
infiltration
how do you find average weighted c-value of a watershed? - Answers divide each acre section
by 100
true or false: urban growth trees were found to typically have larger and more effective canopies
for intercepting rainfall than forest grown trees - Answers true
which type of tree - deciduous or evergreen - was shown to be more effective at rainfall
interception regardless of region? - Answers evergreen
in which region - southeast of pacific northwest - was a higher percentage of precipitation
captured by tree canopies? - Answers pacific northwest
if you were calculating runoff using the rational formula, which variable (C,I, or A) would best
describe the impact of tree canopies on runoff based on the article "Give Me the Numbers"? -
Answers I
What does LID stand for? - Answers low impact development
What two major components make up the Lh for a watershed? - Answers overland flow and
channel flow
In the storm water runoff hydrograph, the point at the top of the curve (N) represents: - Answers
peak runoff rate and time of peak
the shaded area beneath the curve on the hydrograph represents: - Answers Qvol
The two portions of this stream hydrograph identified at top and bottom of curves repectively: -
Answers base flow; storm flow
true or false: infiltration is the primary hydrologic process supporting stream base flow -
Answers true
true or false: runoff on a slop typically flows downhill perpendicular to the contours - Answers
true
true or false: the rational formula is most appropriate for use in relatively small watersheds
because inherent model error becomes excessive as the watershed are gets larger - Answers
true
determining Qvol is an essential hydrologic modeling practice because it allows the designer to:
- Answers size storage areas appropriately
why did teague and kuehler's research show that trees in the NW capture and retain more
rainfall than trees in the SE? - Answers rainfall events in the NW are less intense than in SE
a slope of 6% is equivalent to a ratio of: - Answers 16.67H:1V
a depression pond is proposed. what is the mose correct point for the at-grade overflow? -
,Answers the lowest point within the water limits
in the article "Give Me the Numbers", when comparing comparably sized trees, what kinds of
trees were most effective at capturing and retaining rainfall volume in the canopy? - Answers
conifers
true or false: creating an impervious area on a site will typically increase both Qp and Qvol. -
Answers false
along the centerline of a gradually descending roadway, the 426 contour is 135' away from the
420 contour. the gradient of the road is: - Answers D=L/G
G=L/D
G= 6/135
G=.044 = 4.44%
true or false: the faster the time of concentration, the lower the intensity. - Answers false
true or false: Teague and Kuehler's research found that the typical forest frown tree most
commonly has a more effective canopy for rainwater capture than the typical urban tree -
Answers false
a co-worker of yours calculated before-development and after-development site stormwater
runoff using the rational formula and also SCS method for an 18-acre watershed. he carefully
followed the procedures you have learned. based on the results, which finding is most correct? -
Answers both are equally correct even with different results
the LH for a watershed includes 1,800 feet of a mountain stream. if the channel drops 20 feet
over that distance, approximately how long will it take water to travel that distance (rounding to
the nearest minute) - Answers 14 mins - use figure 11.4 (nomograph for channel flow time)
true or false: given equal lengths and slope of flow, overland flow is typically faster than channel
flow - Answers false
both the FAA formula for calculating the time of concentration and the SCS method for
calculating the time of concentration rely on what criticl information? - Answers slope, land
surface characteristics, LH length
a reasonable minimum slop for reliable draining turf area is: - Answers 2%
a map is drawn at 1:24,000. which side of a standard engineering scale should you measure it
with? - Answers 1 inch = 24000 in
1 inch = 24000/12
, 1 inch = 2000 ft
20 scale
the modified rational formula "improves" the rational formula by accounting for: - Answers
antecedent precipitation
which topographic form (swale, ridge, constant) is most likely to exhibit the longest sheet flow
condition? - Answers ridge
when designing a development on a site which currently is undeveloped, and modeling runoff
using the SCS method, keeping the first portion of the LH in its existing condition is important
because: - Answers sheet flow accounts for more travel time than shallow concentrated flow &
maintaining a longer time of concentration will minimize increase runoff due to development
the Tc for an Athens, GA watershed is 34.3 minutes. what is the intensity (in/hr) for the 50 year
event in the watershed? - Answers use table provided
when applying the modified rational formula, why must adjusted C values must not exceed 1.0?
- Answers it represents a percentage of runoff and you cant have over 100%
true or fall: given equal slope and soil conditions, good dense forest usually generates less
runoff than good dense turf grass. - Answers true
based on the following watershed information, what is the peak rate of runoff? - Answers Qp=
CIA
=.37(34.23)(4.49)
=56.87
true or false: based on our class discussions, Qd is understod to be the runoff depth. - Answers
true
true or false: when comparing watersheds in the same geographic setting using the SCS
method, the major factor influencing Qvol is CN - Answers true
a storm event is calculated to produce 1.00 acre-feet of runoff from a 4.7 acre watershed. what
is the equivalent volume in cubic feet? - Answers 43,560 CF
which of the following stormwater management practices controls both Qp and Qvol? - Answers
infiltration
how do you find average weighted c-value of a watershed? - Answers divide each acre section
by 100
