Millers Rainwater Project

1
Millers Rainwater Project
Briarcliff Raingarden
After
Before
2
Plymouth Pond
After
Before
3
Storm Comparison 1 Hydrographs
2003
Total Rain 0.6 inches in 2 hours prior to
highest flow 1 inches total of rain received on
April 4
Note plymouth transducer was offline
Total Rain 0.62 inches in 2 hours prior to
highest flow 0.97 inches total of rain received
on May 11-May 13.
2010
Prior moisture conditions In 2003, off and on
rains occurred throughout the day of the storm.
In 2010, off and on rain occurred throughout 2
days prior to the storm. Both years had
substantial rains 6 days prior to dates shown on
graph.
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Storm Comparison 1 Water Calculations for
Glazier Way study site
Watershed size 1.519 mi2
April 4, 2003
May 13, 2010

• Inches of rain during storm 0.62 inches
• Total amount of rain 2,188,216 ft3
• Percent of rain leaving system via stream 52
  (1,131,702 ft3)
• Percent of rain trapped in BMPs, soil, plants,
  ponds, or evaporated
• 48 (1,056,514 ft3)
• Percent of rain trapped in 75 rainbarrels
  (assuming they fill completely) 0.03 (602 ft3)
• Percent of rain absorbed by Thurston Elementary
  Raingarden 0.01 (191 ft3)
• Percent of rain absorbed by Briarcliff
  Raingarden 0.10 (2,118 ft3)
• Peak Flow 131 cfs
• Time from peak rain to peak flow
• 1 hour, 20 min

• Inches of rain during storm 0.70 inches
• Total amount of rain 2,470,258 ft3
• Percent of rain leaving system via stream
• 43 (1,064,717 ft3)
• Percent of rain trapped in soil, plants, ponds,
  or evaporated
• 57 (1,405,541 ft3)
• Peak Flow 184 cfs
• Time from peak rain to peak flow 5 min
• Rate of flow increase, once flow started to
  increase
• Approx 1.5 cfs/min
• Length of time it takes to return to pre-storm
  flow
• 14 hours 6 min

5
Storm Comparison 2 Hydrographs
Total Rain 0.4 inches in 2 hours (plus an
additional 0.1 inches earlier in the day)
2003
Total Rain 1 0.5 inches mostly within 2
hours Peak Flow 42 cfs Time from peak rain to
peak flow 2 hours Total Rain 2 0.42 inches
mostly within 1 hours Peak Flow 49 cfs Time
from peak rain to peak flow 1 hr, 24 min
2010
Prior moisture conditions 2003 had only minor
precipitation throughout March. 2010 had a major
storm (about 1 inch rain) five days prior to
dates shown on graph.
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Storm Comparison 2 Water Calculations for
Glazier Way study site
Watershed size 1.519 mi2
March 20, 2003
May 7, 2010 (note these numbers are for the
second peak, indicating pre-existing wet
conditions

• Inches of rain during storm 0.42 inches
• Total amount of rain 1,482,155 ft3
• Percent of rain leaving system via stream
  Difficult to determine w/ 2 rain peaks
• Percent of rain trapped in BMPs, soil, plants,
  ponds, or evaporated
• Difficult to determine w/ 2 rain peaks
• Peak Flow 49 cfs
• Time from peak rain to peak flow
• 1 hour, 24 min
• Rate of flow increase, once flow started to
  increase
• Approx 0.61 cfs/ min
• Length of time it takes to return to pre-storm
  (peak 1) flow
• 48 hours

• Inches of rain during storm 0.4 inches
• Total amount of rain 1,411,576 ft3
• Percent of rain leaving system via stream
• 29 (414,465 ft3)
• Percent of rain trapped in soil, plants, ponds,
  or evaporated
• 71 (997, 111 ft3)
• Peak Flow 82 cfs
• Time from peak rain to peak flow 19 min
• Rate of flow increase, once flow started to
  increase
• Approx 1.1 cfs/min
• Length of time it takes to return to pre-storm
  flow
• 48 hours

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Storm Comparison 3 Hydrographs
Total Rain 0.4 inches in 3 hours (first peak
only) with 0.2 inches in 1 hour
2003
Total Rain 0.40 inches in 5 hours (first peak
only) With 0.19 inches in 1 hour.
2010