Broward Rainfall & Discharge Analysis. TAC Friday December 20 th, 2013 Michael Zygnerski

Transcription

1 Broward Rainfall & Discharge Analysis TAC Friday December 20 th, 2013 Michael Zygnerski

2 Objectives Review local and regional hydrologic patterns and variability, both recent and historic. Evaluate rainfall trends relative to water management considerations. Consider longer-term implications on system capacity.

3 Outline Present recent rainfall data Examine rainfall variations Yearly Monthly Spatially & Temporally Evaluate design storm frequency Examine relationship of rainfall to structural inflows/outflows Demonstrate recharge capacity Present findings

4 Rainfall Cumulative average rainfall for LEC SA2 (Broward): November influence 7.13 (217% above ave)

5 Seasonal Rainfall

6 Regional Averages

7 Comparison to Other Major Cities City Inches City Inches Atlanta, Georgia 49.7 Nashville, Tennessee 47.3 Austin, Texas 34.2 New Orleans, Louisiana 62.7 Baltimore, Maryland 41.9 New York, New York 49.9 Birmingham, Alabama 53.7 Oklahoma City, Oklahoma 36.5 Boston, Massachusetts 43.8 Orlando, Florida 50.7 Buffalo, New York 40.5 Philadelphia, Pennsylvania 41.5 Charlotte, North Carolina 41.6 Phoenix, Arizona 8.2 Chicago, Illinois 36.9 Pittsburgh, Pennsylvania 38.2 Cincinnati, Ohio 41.9 Portland, Oregon 43.5 Cleveland, Ohio 39.1 Providence, Rhode Island 47.2 Columbus, Ohio 39.3 Raleigh, North Carolina 46 Dallas, Texas 37.6 Richmond, Virginia 43.6 Denver, Colorado 15.6 Riverside, California 10.3 Detroit, Michigan 33.5 Rochester, New York 34.3 Hartford, Connecticut 45.9 Sacramento, California 18.5 Houston, Texas 49.8 Salt Lake City, Utah 16.1 Indianapolis, Indiana 42.4 San Antonio, Texas 32.3 Jacksonville, Florida 52.4 San Diego, California 10.3 Kansas City, Missouri 39.1 San Francisco, California 20.7 Las Vegas, Nevada 4.2 San Jose, California 15.8 Los Angeles, California 12.8 Seattle, Washington 37.7 Louisville, Kentucky 44.9 St. Louis, Missouri 41 Memphis, Tennessee 53.7 Tampa, Florida 46.3 Miami, Florida 61.9 Virginia Beach, Virginia 46.5 Milwaukee, Wisconsin 34.8 Washington, DC 39.7 Minneapolis, Minnesota 30.6 NOAA's Climate Normals

8 Rainfall Variations Demonstrate high monthly variability

9 Yearly Rainfall-std dev Rain Year (in) Broward 30-yr average = Standard Deviation = 7.47

10 Monthly Rainfall Averages

11 Broward Monthly Rainfall

12 Monthly Rainfall- Standard Deviation January 1.63 February 1.81 March 1.83 April 2.33 May 3.22 June 4.57 July 2.23 August 2.46 September 2.6 October 4.63 November 1.9 December 1.48 Based of SFWMD average Broward average rainfall

13 Monthly Rainfall Much greater variability in monthly totals Largest surplus was October 2011 Oct 2011 = in. vs Ave of 5.53 = surplus Largest deficit was June 2004 Jun 2004 = 2.66 in. vs Ave 8.8 = deficit Only 42 of 156 months within 1 in. of historical average (27%)

14 Spatial & Temporal Variability

15 Summary points Rainfall highly variable temporally & spatially Important to capture for beneficial use Drought buffering Flood protection adds complexity

16 Storm Frequency Design storm criteria revisions?

17 Design Storms Duration Return Period (yr) Broward Rainfall (in) 1 hr day day day day day day day day Following data for all active DBHYDRO rain station in Broward County for period of January 1998-December 2012 SFWMD - Environmental Resource Permit Information Manual Vol. IV 2009

18 Rain Stations

19 1-Day/5-Year 15+ events

20 3-Day/25-Year 8+ events

21 3-Day/100-Year 2 events

22 100 yr storm Dec in Southern Broward County 1d/100yr = in in. 3d/100yr = in in.

23 10 yr storm Oct tidal event 1d/10yr = 7-11 in 6.24 in. 3d/10yr = in in.

24 NOAA Atlas 14, vol 9 (2013) Recent NOAA study revisited storm probabilities and showed minor change from SFWMD estimates (net Δ -0.4 in) Location SFWMD NOAA Δ (in) Deerfield FLL Hallandale NNR & Flamingo Hillsboro & C-11 & US *Preliminary analysis by Lenny Vialpando

25 Comparison of 100yr- 1day maps

26 Regional Structure Operations Routing water: Where, When, & How Much * Structure Data used in this analysis spans Jan 2000 Dec 2012

27 SFWMD Structures- Inflows 5 primary structures control inflows from WCA and upstream District canals Structure Basin Design Capacity (cfs) S-39 Hillsboro 800 S-38 C S-124 C-13/NNR 490 S-34 NNR 350 S-30 C-9 560

28 Inflows 25.3% 2.3% 30.6% 39.3% Of the total yearly values Most of the inflows come from S-39 (30.6%) S-38 (39.3%) S-34 (25.3%) Other structures S-124 (2.3%) S-30 (2.6%) 2.6%

29 Inflows 2.78 Yearly average total flow in billions of cubic feet Structure Billion ft 3 Acre*ft S ,820 S ,185 S ,030 S ,821 S , billion cubic foot ~ 23,000 acre*ft

30 Yearly Inflows

31 Inflows

32 Inflows S-38 (C-14), S-39 (Hillsboro), and S-34 (NNR) provide majority of inflows Month by month data shows all inflows greatly decrease during water restriction conditions Most inflows occur during end of wet season through beginning of dry season

33 SFWMD Structures- Discharges 10 primary structures control discharges from Broward Basins 8 Discharge to Ocean 2 Discharge to WCAs* *G-123 not operated since Jan 2004 ** S-9 & S-13 only pump driven stations Structure Basin Design Capacity (cfs) G56 Hillsboro 1600 G57 Pompano 375 S37A C S36 C S33 C G54 NNR 1300 S13 C S-9 C S-29 C G-123 NNR 400

34 SFWMD Structures- Discharges 0.9% 16.4% 3.7% 10.1% 17.0% Of the yearly total discharge values 0.9% 12.0% 0.4% Most discharges are through S29 (27.1%) G56 (17.0%) S9 (16.4%) S37A (12.0%) S13 (11.6%) G54 (10.1%) Other structures 11.6% S36 (3.7%) 27.1% G57 (0.9%) G123 (0.9%) S33 (0.4%)

35 SFWMD Structures- Discharges Of the Smaller discharges S36 (3.7%), G57 (0.9%), and S33 (0.4%) have much smaller basins than other structures G57 is in close proximity to S37A which receives discharges from neighboring C-14 West

36 SFWMD Structures- Discharges 5.94 Yearly average total flow in billions of cubic feet Structure Billion ft 3 Acre*ft S ,401 G ,364 S ,543 S-37A ,189 S ,975 G ,497 S ,614 G ,117 G ,117 S ,984 *S-9 & S ,518

37 SFWMD Structures- Discharges

38 SFWMD Structures- Discharges All

39 SFWMD Structures- Discharges Yearly Restrictions Restrictions Restrictions

40 SFWMD Structures- Discharges Consistently all major structures are discharging most in the wet season between June and October Unlike inflows, discharges still occur on a basin scale during water restrictions due to local runoff Seasonal Averages (cfs): Wet: 9,670 Dry: 3,667

41 Inflows & Discharges (*9.78)

42 LIDAR More discharges in southern Broward due to lower land elevation/storage

43 Comparison of All- Billion ft3

44 Yearly Comparison of All

45 Summary Points Total volume of rain out number total discharges (infiltration) which are greater than total inflows Highest inflows come from stations further north higher water levels in WCA also occur further north Most discharges come from structures with largest basins and that are better connected to regional system S29 has highest discharge but receives minimal regional deliveries discharges generated from basin runoff and possible seepage Volume of discharges ~ ½ rainfall for

46 Recharge Fran Henderson- April 14, 2011

47 Broward Rainfall

48 G /17 -> 3.18 ft 3/18 -> 5.26 ft

49 G-57 Rain Station 5.5 inches of rainfall resulted in GW increase of + 2 ft.

50 Summary Points Local water resource conditions most strongly influenced by basin-specific influences More and larger regional diversion impoundments (and potentially ASR), coupled with canal interconnects, continue to be a wise water management strategy Topographically higher capacity for storage in northern Broward more interconnects and alternative routing strategies may be needed Same interconnects may help with other regional projects such as C-51