The Sustainability of Floods Pond

Transcription

1 The Sustainability of Floods Pond Bangor Water District s Public Water Supply Presented By: Rick Pershken Bangor Water District

2 Overview Brief BWD History Watershed Characteristics Lake Characteristics Safe/Sustainable Yield Pumpage & Usage Records Precipitation Records Lake Levels

3 BWD History The Bangor Water District was formed in 1957 Prior to the formation of the Water District, water was supplied by the City of Bangor from a treatment plant located on the Penobscot River March 10, 1951 And while this water is somewhat less vile than that which Philadelphia drinks, it has a noticeable flavor of rotten sawdust and moose tracks.

4 BWD History Initially looked at ground water (Veazie) and surface water sources. Floods Pond in Otis was eventually selected Johnston Pump Station, 5 miles of road, overhead electric and 17 miles of transmission main were constructed for a cost of $4,000,000 (about 32.2 million today) Butler Water Treatment Facility Constructed ($8,000,000) 2013 UV Facility Constructed ($3,000,000)

5 Watershed Map Drainage Area 8.8 square miles (5,632 acres). Topography Hills and lakes, glacial scoured. Soils Glacial till based Dixfield- Colonel-Lyman- Brayton association. Land Use Forested, managed sustainably.

6 Watershed Characteristics Burnt Pond 326 acres, 33 feet deep Little Burnt Pond 10 acres 15 ephemeral and 1 perennial inlet streams Tannery Brook - outlet 1% Wetland Sand & Gravel Aquifers - none 98.7% Owned or Protective Agreement

7 Bedrock Lucerne Granite

8 Lake Characteristics Surface area 756 acres Maximum Depth 142 feet Spillway feet, fixed crest Mean Depth 41 feet Usable Storage 4.5 billion gallons to elevation 282 Temperature 33.2 low, 74.5 High, 50.7 Avg. Quality Coldwater Lake high quality, oligotrophic Secchi Disk 23 to 26 feet/thermocline Biology Arctic Charr. Spawn at Kimball Point on shallow cobble shoal highly susceptible to water level fluctuations

9 Depth Map

10 Charr Sustainability Charr Management Plan (IF&W, BWD) Limit BWD withdrawal to 6 MGD (1990) Limit BWD withdrawal to 6.5 MGD (1991) Withdrawal limit no longer appropriate (1996) IF&W & BWD Joint management of Charr Employ range of alternatives to withdrawal limitations to ensure sustainability of the Charr. Annual monitoring of Charr population. Kimball Point Dec. 2001, Elev /- October, 2009 Elev /-

11 Elevation of Charr Spawning Beds

12 Safe/ Sustainable Yield Difficult to define. Safe yield is more of a maximum drought yield while sustainable yield may be more conservative as it considers maintaining baseflow. The use of the term safe yield is declining.

13 Regulations Chapter 587 In-stream Flows and Lake and Pond Water Levels (2007) establishes river and stream flows and lake and pond water levels to protect natural aquatic life and other designated uses in Maine 's waters Standard Allowable Alteration April 1 to July 31 (1 foot drawdown) August 1 to March 31 (2 foot drawdown) Public Water Utilities - these requirements will not apply to an existing Community Water System operating within its system design capacity providing that (1) the Community Water System, so operating, cannot attain the applicable requirements, and (2) the Community Water System has received, and is operating in accordance with, or is otherwise satisfying the requirements of, a Community Water System Withdrawal Certificate issued by the Department. A Community Water System Withdrawal Certificate will be issued by the Department to any existing Community Water System that demonstrates that it cannot operate at its system design capacity and attain the applicable flow or water level requirements of this chapter. There is also a drought flow variance for Community Water Systems

14 Safe Yield Black & Veatch (1989) Used a monthly water balance equation; Water In = Water Out +/- Changes in Storage Analyzed for period of March 1948 to February 1952 (2 nd driest period on record). Assumed a maximum of 23.5 foot drawdown Results 8.2 MGD safe yield.

15 Safe Yield Rule of Thumb 1 Square Mile = 1 MGD Average Yield in Maine (MGD) = DA (acres) * 43,560 ft2/acre * 7.48 gal/ft3* 0.5 (APT) / 365 days/year/1,000,000 DA = drainage area (acres) APT = average annual precipitation (feet) Floods Pond average annual yield = 8.8 MGD Drought Yield = 8.8 * 85% = 7.5 MGD 50% = 4.4 MGD The more conservative the more sustainable

16 Johnston Pump Station Two intakes: one 185 feet long at 292 feet (13.5 ); the other 302 feet long at feet (23 ). Four 3,000 GPM x 150 HP, vertical turbine pumps Initial Maximum Design Capacity = 16 MGD. Current Design Capacity 13 MGD (limited by Ozone Treatment Plant 1995).

17 Water Pumped Aug Summer Peaks 5.00 MGD PUMPED Winter Lows 3.77 (Dec.) Oct-97 Nov-99 Dec-01 Jan-04 Feb-06 Mar-08 Apr-10 May-12 Jun-14 Jul-16 DATE

18 Water Pumped as Percentage of Safe Yield (8.2 MGD) 100% 90% 80% 70% 68% 67% PERCENT OF SAFE YIELD 60% 50% 40% 30% 20% 10% 0% Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13 DATE

19 Pumped Vs. Metered Water Used Water Pumped WATER USED (MGD) Metered Water YEAR

20 Unmetered/Unaccounted Water Unmetered - Hydrant & Main Flushing Standpipe Draining Process Water Fire Fighting Main Breaks Unaccounted for Leaks we don t know about Unauthorized use or unreported use Measurement inaccuracy

21 Precipitation Average annual precipitation = 42 8 drought periods in the record with the two worst occurring between (Before use as PWS) and between Drought What is It? 85% of average annual precipitation A period of below average water content in streams, reservoirs, ground water aquifers, lakes and soils. a deficit of precipitation sufficient to create stress on and competition for otherwise adequate drinking water supplies Schmitt 2003 Palmer drought severity index is negative 2.0 or less

22 Historical Precipitation % % MONTHLY PRECIPITATION (INCHES) % 100% 80% 60% 40% PERCENTAGE OF AVERAGE ANNUAL PRECIPITATION % 0.0 1/2/1991 1/2/1993 1/3/1995 1/3/1997 1/4/1999 1/4/2001 1/5/2003 1/5/2005 1/6/2007 1/6/2009 1/7/2011 1/7/2013 0%

23 Lake Levels Natural Outlet Level = New dam lake level (1978) = October, 2001 Level = 301 +/- Steve on the Dam Level = 306 +/- June, 2013

24 Low Lake Levels Floods Pond Lowest Annual Intake Level spillway Feet outlet pipe Natural charr beds New Beds - Down to

25 Lake Levels More Conservative = More Predictable? Spillway Crest LAKE LEVEL (FT) Pipe Outlet /24/01 Record Ground Water Low in Closest USGS Bedrock Well Ground water/surface Water Interaction? /13/ /23/88 9/19/91 6/15/94 3/11/97 12/6/99 9/1/02 5/28/05 2/22/08 11/18/10 8/14/13 5/10/16 DATE

26 The Sustainability of Floods Pond Bangor Water District s Public Water Supply Presented By: Rick Pershken Bangor Water District

27 Partial List of References The Soils of Maine, John A. Ferwerd, Kenneth J. LaFlamme, Norman R. Kalloch, Jr., Natural Resources Conservation Service, USDA and Robert V. Rourke Department of Applied Ecology and Environmental Sciences, University of Maine. Geologic map of the Lucerne Granite, Hancock and Penobscot Counties, Maine Wones, D.R., and Ayuso, R.A. Publishing Organization: U.S. Geological Survey SUSTAINABLE YIELD OF GROUNDWATER Victor M. Ponce May Dina Page, Kathy Moriarty, Data, Photos, Advice. Bangor Water District THE EFFECTS OF THE DROUGHT ON MAINE DRINKING WATER SUPPLIES, DRINKING WATER PROGRAM Department of Health & Human Services Catherine Schmitt January 2005 Management Plan Landlocked Arctic Charr Floods Pond, Otis, Maine, 1996.