Hydrology and Water Quality Considerations in NH Lakes Region. Barbara McMillan

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2 Hydrology and Water Quality Considerations in NH Lakes Region Barbara McMillan

3 Watershed

4 Watershed

5 Watershed

6 The Water Cycle

7 Undeveloped Area 50% soaks in 10% runs off

8 Highly Developed Area 15% soaks in 55% runs off

9 Credit: Think Blue Maine stormwater runoff Water from rain or melting snow that doesn t soak into the ground. rain water runoff stormwater C:\barb\RainGarden.mp4

10 Why does it matter? Stormwater runoff causes or contributes to over 90%?% of the water pollution problems in NH.

11 Why does it matter? Aquatic Life Use Primary Contact Recreation

12 Two Runoff Issues 1. CARRIES POLLUTION 2. TOO MUCH WATER

13 1. Carries Pollution

14 Sediment

15 Nutrients

16 Pathogens

17 Toxic Contaminants

18 Chlorides (Road Deicing Agents) Water Softener, 2% Salt Piles, 7% Food Waste, 1% State Roads, 9% Atmospheric Deposition, 1% Parking Lots, 50% Municipal Roads, 27% Private Roads, 3% Sources of chloride in Policy Brook, Salem

19 Liability Protection Walking on snow and ice is inherently dangerous

20 2. Effects of Too Much Water

21 Too Much Water Natural/undeveloped Urban/highly developed Runoff Rate The peak flashiness is reduced Time

22 Effects of Too Much Water

23 Impacts to Water Undeveloped Maintained PRE-Development lawn forest Runoff 6% slope volume: to lake3,000 ft 3 Home Sandy TSS: 123,350ft loam pounds soil 2 Pit Paved Phosphorus: and drive mound ft topography pounds 2 Nitrogen: 0.4 pounds POST Runoff - Development volume: 3,000 ft 3 Runoff TSS: volume: 12 pounds 28,000 ft 3 (9X) TSS: Phosphorus: 55 pounds (5X) 0.03 pounds Phosphorus: Nitrogen: pounds (16X) Nitrogen: 2.9 pounds (7X) Adapted from Jeff Schloss, UNH CE and Wisconsin Dept. of Natural Resources and the Wisconsin Lakes Partnership using the Simple Method and the Residential Loading Models. Photo source:

24 NH Lakes

25 Some Top Concerns About Our Lakes Stormwater Runoff Overall Water Quality Population Growth & Shoreland Development Air-Borne Pollution (acid deposition, mercury) Threats and Impairments from Invasive Species

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30 nutrients

31 Phosphorus in NH Lakes resuspension and release from sediments shoreline erosion street runoff Lawn clippings Fertilizer wastewater From Winnipesaukee Gateway

32 The Impact of Phosphorus PHOSPHORUS P More Phosphorus Leads to: A L G A E More Plant and Algae Growth S D Lower Water Clarity D. O. Lower Dissolved Oxygen

33 Algae Impacts water clarity Too many nutrients can increases in algae... and possibly Cyanobacteria!

34 Another Big Problem Invasive Aquatic Species Impair designated uses of waterbodies Can cause declines in shorefront property values

35 HIGH RISK! HIGH RISK!

36 What can we do to protect NH Lakes?

37 Questions or Comments? Have questions? Want to get involved? Barbara McMillan, NHDES Watershed Assistance Section

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39 Phosphorus in NH Lakes Watershed P Loads to Webster Lake Atmospheric Direct Rainfall Septic Systems Source Mass (kg) % of Total Watershed Direct Rainfall Atmospheric Septic Systems Total Watershed Watershed P Loads (VHB, 2006)

40 Nutrients : Algae : Clarity Relationships Increases in nutrients (P) Increases in algae (chl-a) Decreases in lake clarity (SD) Decreases in property values!

41 Activities and Factors in the Watershed that Can Affect Water Quality Construction Road Runoff Shoreline Erosion Forestry Activities Fertilizing Washing Cars Septic System Failure/leaking Herbicide Application Sediment Disruption Farming/Animals Gasoline Spills Urban Development Commercial Development Improperly Constructed Beaches

42 Nitrogen in Great Bay Total Nitrogen Load NPS Nitrogen Load Wastewater Treatment Facilities 32% Non-Point Sources, 68% CHEMICAL FERTILIZER BREAKDOWN: Human Waste, 29% Animal Waste, 14% 70% from lawns (10.5% of total NPS load) Chemical Fertilizer, 15% 22% from agriculture 8% from recreational fields, including golf courses Atmospheric Deposition, 42% Data source: GBNNPSS, DES 2014

43 What can we do to protect Great Bay? Photo: Jerry & Marcy Monkman

44 What is Internal P Loading? Sediments consist of solid particles separated by liquid-filled interstitial spaces containing pore water. The sediment-water interface is the barrier to free interchange of phosphorus between sediments and lake water. If the interface is anoxic phosphate ions can pass between the sediments and lake water. If the interface is oxygenated, phosphate ions are precipitated and do not pass freely to lake water.

45 Revised Watershed P Loads Septic Systems Atmospheric Watershed P Loads to Webster Lake Internal Source Mass (kg) % of Total Watershed Direct Rainfall Atmospheric Septic Systems Internal Total Direct Rainfall Watershed

46 NH Lakes that Experience Cyanobacteria Blooms Greenwood Pond, Kingston Country Pond, Newton French Pond, Henniker Monomonac Lake, Rindge Harvey Lake, Northwood Turtle Pond, Concord Baboosic Lake, Amherst Webster Lake, Franklin Bow Lake, Northwood Long Pond, Pelham Showell Pond, Sandown Phillips Pond, Sandown Robinson Pond, Hudson York Pond, Berlin Pawtuckaway Lake, Nottingham Harris Pond, Pennichuck Water Works, Nashua Bow Lake, Northwood, 2006

47 Merrell and Howe 2008

48 Merrell and Howe 2008

49 Top 10 Big Lakes in NH Waterbody Name / Town Area (acres) Winnipesaukee / Wolfeboro 44, Umbagog / Errol 7, Squam Lake / Holderness 6, Winnisquam / Belmont 4, Newfound Lake / Bristol 4, Sunapee Lake / Sunapee 4, Moore Reservoir / Littleton 3, Ossipee Lake / Ossipee 3, Lake Wentworth / Wolfeboro 3, Massabesic Lake / Auburn 2,899.94

50 Trophic Status of NH Lakes Eutrophic 176 lakes 22% Oligotrophic 230 lakes 29% Mesotrophic 387 lakes 49%

51 Activities and Factors in the Watershed that Can Affect Water Quality Construction Road Runoff Shoreline Erosion Forestry Activities Fertilizing Washing Cars Septic System Failure/leaking Herbicide Application Sediment Disruption Farming/Animals Gasoline Spills Urban Development Commercial Development Improperly Constructed Beaches