Ballston Lake Management Plan

June 14, 2022

TABLE OF CONTENTS
1 Executive Summary ................................................................................................................. vii
2 Objectives and Scope................................................................................................................ 1
3 Cultural and Environmental Setting ...................................................................................... 2
3.1 Ballston Lake and Watershed ......................................................................................................................... 2
3.2 Land Use and Development Patterns .......................................................................................................... 6
4 Ballston Lake Water Quality Status and Trends ............................................................... 13
4.1 Regulatory Classification and Best Use .................................................................................................... 13
4.2 Limnological Characteristics and Trophic State ................................................................................... 15
4.2.1 Physical Characteristics and Stratification Regime .............................................................. 15
4.2.2 Trophic State and Water Chemistry .......................................................................................... 16
4.3 CSLAP Results from 2020 .............................................................................................................................. 22
4.4 Long-Term Water Quality Trends .............................................................................................................. 23
4.5 Emerging Issues ................................................................................................................................................ 25
4.5.1 Cyanobacterial Blooms ................................................................................................................... 25
4.5.2 Pathogenic Microorganisms ........................................................................................................ 26
4.5.3 Organic Micropollutants ................................................................................................................ 28
4.5.4 Flooding ............................................................................................................................................... 29
5 Ballston Lake Biological Community Status and Trends .............................................. 30
5.1 Macrophyte Community ................................................................................................................................ 30
5.2 Fish Community ................................................................................................................................................ 31
5.3 Benthic Community ......................................................................................................................................... 33
6 Sources of Phosphorus .......................................................................................................... 33
6.1 External Loading: Watershed and Groundwater Contribution ....................................................... 33
6.1.1 Subwatershed Monitoring Data.................................................................................................. 33
6.1.2 Modeled Estimates of Phosphorus Load................................................................................. 35
6.2 Internal Loading ................................................................................................................................................ 39
7 Recent Actions to Advance Lake Management ............................................................... 41
7.1 Water Quality Testing ..................................................................................................................................... 41
7.2 Town of Ballston Sewer District and Ballston Lake Public Sewer Project ................................... 42
7.3 Regulatory and Programmatic Initiatives for Water Quality ........................................................... 43
7.3.1 Municipal Codes and Guidelines ................................................................................................ 43
Ballston Lake Management Plan ii February 2022
7.3.2 New York State Initiatives ............................................................................................................. 44
8 Management Alternatives .................................................................................................... 45
8.1 Reduce External Loads of Phosphorus and Sediment ....................................................................... 45
8.1.1 Improved Wastewater Collection and Treatment ................................................................ 45
8.1.2 Improved Stormwater Management ........................................................................................ 47
8.1.3 Agricultural Best Management Practices ................................................................................ 48
8.1.4 Lawn Care Best Management Practices ................................................................................... 50
8.1.5 Land Protection and Preservation .............................................................................................. 51
8.1.6 Education and Outreach ................................................................................................................ 52
8.2 Reduce Internal Load of Phosphorus ....................................................................................................... 53
8.3 Invasive Species Management .................................................................................................................... 55
8.3.1 Current Conditions ........................................................................................................................... 55
9 Macrophyte Management Strategies ................................................................................ 56
9.1 Overview .............................................................................................................................................................. 56
9.2 Physical Control Measures ............................................................................................................................ 59
9.2.1 Hand Harvesting ............................................................................................................................... 59
9.2.2 Benthic Mats ....................................................................................................................................... 61
9.2.3 Mechanical Harvesting ................................................................................................................... 62
9.2.4 Diver Harvesting and Diver-Assisted Suction Harvesting (DASH) ................................. 63
9.3 Aquatic Herbicides ........................................................................................................................................... 64
9.4 Biological Methods .......................................................................................................................................... 68
9.4.1 Herbivorous Insects ......................................................................................................................... 69
9.4.2 Herbivorous Fish (Grass Carp; Ctenopharyngodon idella) ............................................... 70
9.5 Education and Outreach ................................................................................................................................ 71
9.6 No Action Alternative ..................................................................................................................................... 72
10 Recommended Actions and Implementation Plan ........................................................ 73
11 Adaptive Management ........................................................................................................... 77
12 Glossary ..................................................................................................................................... 80
13 Resources .................................................................................................................................. 82
14 References ................................................................................................................................ 84
15 Appendices ............................................................................................................................... 88