2012-09-20_HYDROLOGY - M1987049

• Permit No: M1987049
• IBM Index Class Name: HYDROLOGY
• Doc Date: 9/20/2012
• Doc Name: AMENDMENT TO COMBINED SUBSTITUTE WATER SUPPLY PLAN
• From: DWR
• To: BISHOP-BROGDEN ASSOCIATES
• Email Name: BMK
• Media Type: D
• Archive: No

Month
Exposed
Ground
Water Area
(acres)
[1]
Gross
Evaporation
Rate
(inches)
[2]
Effective
Precipitation
Rate
(inches)
[3]
Net
Evaporation
Rate
(inches)
[4]
Historical
North
Tower Pit
ET Credits
[5]
Net
Evaporation
[6]
Gravel Production
Aggregate
Moisture
Content
Depletion
[8]
Total
Site
Depletion
[9]
Lagged
Site
Depletion
[10]
Above
GW Table
(tons)
Below
GW Table
(tons)
[7]
Sep
121.5
4.45
0.9
3.6
0.4
35.6
0
160,000
4.7
40.3
48.8
Oct
107.1
3.12
0.5
2.6
0.2
23.2
0
140,000
4.1
27.3
38.6
Nov
107.1
1.78
0.6
1.2
0.0
10.3
0
110,000
3.2
13.5
27.7
Dec 2012
85.6
1.34
0.3
1.1
0
7.7
0
80,000
2.4
10.0
21.1
Jan 2013
53.6
1.34
0.4
1.0
0
4.4
0
80,000
2.4
6.7
16.8
Feb
53.6
1.56
0.3
1.3
0
5.6
0
80,000
2.4
8.0
15.1
Mar
53.6
2.45
0.8
1.6
0.0
7.1
0
110,000
3.2
10.4
15.2
Apr
53.6
4.01
1.2
2.8
0.1
12.5
0
140,000
4.1
16.7
17.7
May
53.6
5.34
1.6
3.8
0.2
16.6
0
140,000
4.1
20.8
20.4
Jun
53.6
6.46
1.1
5.3
0.5
23.3
0
140,000
4.1
27.4
24.0
Jul
53.6
6.68
1.1
5.6
0.7
24.3
0
160,000
4.7
29.0
26.1
Total
-
38.51
8.7
29.8
2.2
170.6
0
1,340,000
39.4
210.0
271.4
[1] Total surface area of exposed ground water is conservatively projected to be 121.5 acres in September 2012, 107.1 acres in October and November 2012, 85.6 acres in December 2012 and
53.6 acres from January through July 2013 (28 acres at North Tower Pit, 20.6 acres at Bromley Lakes Cell 2, 1 acre at Arends Pit from September thru December 2012, and 71.9 acres at
Ready Mixed Pit 1/Bromley Cell 3 which is dewatered to a total of 5 acres by January 2013).
[2] Gross evaporation rate equals 44.52 inches (3.71 ft) per year, based upon NOAA Evaporation Atlas. Monthly distribution based upon SB -120 Guidelines.
[3] Effective precipitation rate equals 70% of total precipitation, based upon average precipitation at the Brighton weather station.
[4] Net evaporation equals [2] - [3].
[5] Historical ET credits at the North Tower Pit from 7.4 acres of pasture grass using ground water at a depth of 4 feet (does not include an effective precipitation credit).
[6] Net evaporation equals the net evaporation volume minus the historical ET credits, [1] x [4]/12 - [5].
[7] Production above and below the static ground water (GW) table. Since the exact timing of production above the GW table is not known, projections conservatively show all production
below the GW table.
[8] Wash water and aggregate moisture content equals 2% by weight for gravel mined above the ground water table and 4% by weight for gravel mined below the ground water table.
[9] Total site depletion equals [6] + [8].
[10] Lagged site depletion equals the depletion in column [9] lagged over 12 months plus depletions from previous lagging patterns.
BBA
- at, on,uir tills 8 I5 IIUP - 8,00c DEN A330c. /ArL' IN(
Table IA
Ready Mixed Concrete Company - Bromley Lakes Site & North Tower Pit
Depletion Analysis (September 2012 - July 2013)
Projections for 2012 -2013 SWSP Amendment
(all values in acre -feet unless specified)
9/5/2012 3 40 PM JAK