Chart 1A

Hackensack River at West Nyack, NY

Sheet 1

Excess Flow in years of Mandatory Water Use Restrictions or Intense Observation by the County of Rockland Historic Median Flow The 50th percentile (median) of daily mean values for each day of 50 years of records Based on USGS Monitoring Site 01376800 / 1.0 mi Downstream of Lake DeForest http://waterdata.usgs.gov/nwis/dvstat?referred_module=sw&search_site_no=01376800&format=sites_selection_links

In Million Gallons Per Day *

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

16.41

18.52

28.56

29.82

18.45

12.80

11.40

10.99

13.14

12.70

13.92

14.76

Sep

Oct

Nov

Dec

(0.73)

(0.21)

(Gallons per day = 7.48051945 gallons per cubic foot x 86,400 seconds per day x Cubic Feet Per Second)* Raw data from USGS

*Computations By Bob Dillon

Key To Chart: Severe or Extreme Droughts in the Hudson Valley based on Meteorological Records Derived from Northeast Regional Climate Center (Cornell)

SD

http://www.nrcc.cornell.edu/drought/NY_drought_periods.html

Droughts derived from NYS Climate Division #5 exceeding 6 months in length

D

http://superfund.ciesin.columbia.edu/Rocklandwater/supply_droughts.html

IO

County of Rockland – Intense Observation MR County of Rockland – Mandatory Water Use Restrictions With No Drought Year

Examples : 2007 January 2005 August

SD SD SD SD

D IO MR D IO MR D D IO MR

1995 July 2002 March 2001 Dec. 1995 Sept. Jan

SD D IO MR

1995

20.15

In Million Gallons Per Day 26.32 Excess Flow - No Drought (1.69) Deficit Flow - No Drought 14.00 Excess Flow - During Drought (0.11) Deficit Flow - During Drought 0.86 Excess Flow - During Severe Drought (0.73) Deficit Flow - During Severe Drought Feb

8.88

Mar

20.25

Apr

6.82

May

Jun

Jul

14.31

14.31

14.00

Aug

0.78

(1.23)

(1.85)

Flow of the Hackensack River at West Nyack, NY:

* Million Gallons Per Day Over or (Under) the 9.75 Million Gallon Minimum Flow Required The NYS DEC Permit for Lake DeForest requires a minimum flow of 9.75 million gallons per day from DeForest. DEC Modification to 6 MGD For Drought / July – November 2002 If Lakes Tappan, Woodcliff and Oradell drop to 50 percent capacity more water can be sent downriver to New Jersey.

SD D SD D D D SD D D D

IO IO IO MR IO IO MR IO IO MR IO IO

Excess Months Drought Months

2007 2005 2002 2001 1999 1997 1995 1993 1991

Jan 26.32 41.56 (1.32) 0.40 (0.30) 26.96 20.15 35.51 37.14

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

(0.01) 23.88 (3.55) (0.40) (0.38) 22.20 8.88 16.75 20.58

49.36 30.95 (0.11) 41.56 0.22 23.25 20.25 76.92 49.94

96.14 55.76 0.38 26.81 (1.13) 34.85 6.82 61.41 27.76

10.16 4.66 0.88 (1.09) (0.56) 13.18 14.31 3.41 16.33

1.00 1.28 0.36 28.90 (1.41) 4.23 14.31 0.68 3.89

2.20 1.88 (2.96) (2.80) (3.23) 0.49 14.00 7.47 6.07

3.24 (1.69) (4.13) (1.87) 2.70 0.05 0.78 15.73 17.90

3.37 11.94 (4.44) (0.03) 58.05 12.38 (0.73) 6.49 10.03

8.20 26.57 (0.56) (2.46) 11.62 14.02 (0.21) (0.60) 1.80

4.20 30.32 0.53 (4.23) 6.89 3.22 (1.23) 0.29 4.15

3.78 43.37 12.45 0.86 8.89 (0.24) (1.85) 1.11 3.32

4 5

4 6

4 6

4 7

4 7

5 7

4 6

2 3

1 2

Excess Flow During Drought Months In Years of County of Rockland Intense Observation 38 1 1 3 2 2 61 3 3 4 3 4 62.3% Of Drought Months Had Excess Flow

Daily Average Net Excess Flow For Drought Months

6.31 Million Gallons Per Day* 5.26 Million Gallons Per Day*

Adjusted For Hurricane Floyd

Excess Months Drought Months

Excess Flow During Drought Months In Years of County of Rockland Mandatory Water Use Restrictions 18 0 0 2 2 2 33 2 2 3 3 3 54.5% Of Drought Months Had Excess Flow

Daily Average Net Excess Flow For Drought Months Adjusted For Hurricane Floyd By: Bob Dillon

http://rocklandraft.com/

2 3

2 3

2 3

1 3

2 3

4.04 Million Gallons Per Day* 1.66 Million Gallons Per Day* *See Sheet 2

Flow of the Hackensack River at West Nyack, NY:

Chart 1A Sheet 2

Million Gallons Per Day Over or (Under) the 9.75 Million Gallon Minimum Flow Required DEC Modification to 6 MGD For Drought / July – November 2002

SD D SD D D D SD D D D

IO 2007 IO 2005 IO MR 2002 IO 2001 IO MR 1999 IO 1997 IO MR 1995 IO 1993 IO 1991

Jan 26.32 41.56 (1.32) 0.40 (0.30) 26.96 20.15 35.51 37.14

Feb

Mar

Apr

May

Jun

Jul

Aug

(0.01) 23.88 (3.55) (0.40) (0.38) 22.20 8.88 16.75 20.58

49.36 30.95 (0.11) 41.56 0.22 23.25 20.25 76.92 49.94

96.14 55.76 0.38 26.81 (1.13) 34.85 6.82 61.41 27.76

10.16 4.66 0.88 (1.09) (0.56) 13.18 14.31 3.41 16.33

1.00 1.28 0.36 28.90 (1.41) 4.23 14.31 0.68 3.89

2.20 1.88 (2.96) (2.80) (3.23) 0.49 14.00 7.47 6.07

3.24 (1.69) (4.13) (1.87) 2.70 0.05 0.78 15.73 17.90

Sep

3.37 11.94 (4.44) (0.03) 58.05 12.38 (0.73) 6.49 10.03

Oct

Nov

Dec

8.20 26.57 (0.56) (2.46) 11.62 14.02 (0.21) (0.60) 1.80

4.20 30.32 0.53 (4.23) 6.89 3.22 (1.23) 0.29 4.15

3.78 43.37 12.45 0.86 8.89 (0.24) (1.85) 1.11 3.32

Excess Flow During Drought Months In Years of County of Rockland Intense Observation

Million Gallons Per Month SD D SD D D D SD D D D

IO IO IO IO IO IO IO IO IO

2007 2005 2002 2001 1999 1997 1995 1993 1991

(40.88)

(99.53)

(3.26)

(9.21)

(10.72)

6.69

1100.90

468.97

627.80 2384.49

11,699.05 191.79 6.31

11.27

27.37 10.82 (91.74) (128.07) (133.18) (17.48) 15.86 (33.64) 866.99 (86.83) (58.01) (1.01) (76.30) (126.78) 26.66 (33.97) (17.22) (42.38) (100.28) 83.67 1741.46 360.22 206.84 275.56 371.27 434.55 96.58 (7.53) 204.52 443.60 429.44 433.90 24.14 (21.76) (6.50) (36.95) (57.30) 20.32 231.61 487.55 194.82 (18.52) 8.68 34.48 188.30 554.77 300.82 55.81 124.37 102.99

Sum Total Monthly Average Net Excess Flow For Drought Months Daily Average Net Excess Flow For Drought Months

Adjusted For Hurricane Floyd 9,114.97 159.91 5.26

Sum Total Monthly Average Net Excess Flow For Drought Months Daily Average Net Excess Flow For Drought Months

Excess Flow During Drought Months In Years of County of Rockland Mandatory Water Use Restrictions

Million Gallons Per Month SD D D SD D

MR 2002 MR 1999 MR 1995

(40.88) (9.21)

4,052.73 122.81 4.04

(99.53) (10.72)

(3.26) 11.27 27.37 10.82 (91.74) (128.07) (133.18) (17.48) 6.69 (33.97) (17.22) (42.38) (100.28) 83.67 1741.46 360.22 627.80 204.52 443.60 429.44 433.90 24.14 (21.76) (6.50)

Sum Total Monthly Average Net Excess Flow For Drought Months Daily Average Net Excess Flow For Drought Months

Adjusted For Hurricane Floyd 1,468.64 50.64 1.66

Sum Total Monthly Average Net Excess Flow For Drought Months Daily Average Net Excess Flow For Drought Months

15.86 206.84 275.56 (36.95) (57.30)