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Milestone II - No-action Alternative - 1987
STUDY TO DETERMINE THE NECESSITY AND, IF APPLICABLE, THE METHODS OF MITIGATING THE DECREASE IN STREAMFLOW AND RELATED EFFECTS ASSOCIATED WITH SEWERING SUFFOLK COUNTY SOUTHWEST SEWER DISTRICT NO. 3 AND NASSAU COUNTY SEWER DISTRICT NO. 3 LONG ISLAND, NEW YORK U.S. EPA GRANT NO. C-36-1036-04 TO SUFFOLK COUNTY MILESTONE II REPORT ON THE NO-ACTION ALTERNATIVE SUFFOLK COUNTY PETER F. COHALAN COUNTY EXECUTIVE FRANK R. JONES DEPUTY COUNTY EXECUTIVE JOSEPH H. BAIER, P.E. PROJECT MANAGER 1981 I COUNTY OF' SU FF'O LK I FRANK R. JONE~ March 13, 1981 I I i,i I I I I I I I I I Mr. Charles S. Warren Regional Administrator United States Environmental Protection Agency 26 Federal Plaza New YQrk, NY 10278 Dear Mr. Warren: SUBJECT: EPA GRANT NO. C-36-1036-04, SUFFOLK COUNTY FLOW AUGMENTATION NEEDS STUDY; MILESTONE II REPORT ON THE NO-ACTION ALTERNATIVE I am pleased to submit the subject report to your office for review, comment and recommendations. The report presents the predicted environmental impacts from the operation of the Suffolk County Southwest Sewer District. Specific environmental factors are discussed, along with the impacts associated with specific streams. The predicted im- pacts are based on the U.S. Geological Su~vey's sub-regional groundwater model which represents the groundwater table, streamflow and underflow systems as a result of the sewering program. Changes in stream dimension and flow are shown, as are the resulting salinity changes in Great South Bay. The salinity information has also been transmitted to your con- sultant, WAPORA, for their analysis. The Milestone II Report contains an executive summary, an introduction to the project and the objectives of this mile- stone. It gives the modeling results for the groundwater system, the streams and Great South Bay, and predicts the environmental changes. The findings of Milestone II will be presented to the communi- ties, the Suffolk County Legislature, local municipalities and environmental groups for their comments and reaction. This will be done during the 45-day EPA review period. I I ! I I I I I I I I I I I I I I I Mr. Warren Page 2 March 13, 1981 The next phase of this project, Milestone III, will begin upon receipt of recommendations for implementation from your office. I would call your attention to the fact that further work cannot begin until a decision on mitigation needs for specific streams and Great South Bay is communicated to this office. This office, staff members and the consultants are available to provide any additional information you may require. Very truly yours, Frank R. Jones Deputy County Executive FRJ/jb I I i I I I i I ! I ! I ! ! I I STUDY TO DETERMINE THE NECESSITY AND, IF APPLICABLE, THE METHODS OF MITIGATING THE' DECREASE IN STREAMFLOW AND RELATED EFFECTS ASSOCIATED WITH SEWERING SUFFOLK COUNTY SOUTHWEST SEWER DISTRICT NO. 3 AND NASSAU COUNTY SEWER DISTRICT NO. 3 LONG ISLAND, NEW YORK U.S. EPA GRANT NO. C-36-1036-04 TO SUFFOLK COUNTY MILESTONE II REPORT ON THE NO-ACTION ALTERNATIVE SUBMITTED BY: SUFFOLK COUNTY PETER F. COHALAN COUNTY EXECUTIVE FRANK R. JONES DEPUTY COUNTY EXECUTIVE JOSEPH H. BAIER, P.E. PROJECT MANAGER 1981 ! ! I I I I I I ! I I I I I i I I I I This document was prepared by Suffolk County, New York, pursuant to 40 CFR, Part 30 and Part 35, Sub. E of the Federal Water Pollution Control Act, Construction Grants. This pro- ject has been financed in part with federal funds from the United States Environmental Protection Agency under Grant No. C-36-1036-04. The contents do not necessarily reflect the views and policies of the United States Environmental Protec- tion Agency, nor does mention of trade names or commercial products constitute endorsement or recommendations for use. I I I I I I I I I I I I I i I I I I ACKNOWLEDGEMENTS This report is a result of the combined efforts of many indi- viduals. Written material was received from the following sources: United States Department of the Interior - Geological Survey, Long Island Section - Syosset,. New York. Tetra Tech, Inc. - Melville, New York; Arlington, Virginia and Lafayette, California. Pandullo Quirk Associates - Wayne, New Jersey. Geraghty & Miller, Inc. Syosset, New York. Suffolk County: Steven Cary Larry Stipp Larry Weisberg Ben Wright The work involved and final product is greatly appreciated. I I 1 I i I I I I I I I I I I I I I I MILESTONE II REPORT ON THE NO-ACTION ALTERNATIVE TABLE OF CONTENTS Chapter I - Introduction Chapter II - Modeling Results Chapter III - Environmental Results . Page No. I-l-1 II-l-1 III-l-1 I I ! I ! i I I ! I I I I I I I I I Table No. II-l-1 II-l-2 II-l-3 II-l-4 II-2-1 II-3-1 III-l-1 III-2-1 III-2-2 III-3-1 III-3-2 III-3-3 III-3-4 LIST OF TABLES Estimated Water Levels for FANS Wells Selected Cross Sections Predicted Total Steady-State, No-Action Flows and Stream Shortening Steady-State and No-Action Streamflow Lake Characteristics Comparison of Steady-State "Present" and "No-Action" Freshwater Inflows to Bay Model . Summary of Environmental Factors Predicted Changes in Stream Environmental Values Predicted Changes in Environmental Factors Summary of Ecological Ratings Summary Table of Aesthetic Rating Summary Table of Stream Recreational Ratings (No Action) Summary Table of Socio-Economic Rankings Page No. II-l-4 II-l-5 II-l-15 II-l-16 II-2-31 II-3-2 III-l-2 III-2-2 III-2-3 III-3-3 III-3-7 III-3-12 III-3-18 I I ! I I I I I I I I I i I I I I I Figure No. I-l-1 I-2-1 II-l-1 II-l-2 II-l-3 II-l-4 II-l-5 II-l-6 II-2-1 II-2-2 II-2-3 II-2-4 II-2-5 II-2-6 II-2-7 II-2-8 II-2-9 II-2-10 LIST OF FIGURES Study Area Streams and Lakes Cross Section A-A Cross Section B-B Cross Section C-C Cross Section D-D Cross Section E-E Predicted Drawdowns Due to Loss of Recharge from Sewering Predicted Stream Characteristics Amityville Creek . Predicted Stream Characteristics Woods Creek Predicted Stream Characteristics Great Neck Creek . Predicted Stream Characteristics Strong's Creek . Predicted Stream Characteristics Neguntatogue Creek . Predicted Stream Characteristics Santapogue Creek - West Branch Santapogue Creek - East Branch . Predicted Stream Characteristics Carll's River Predicted Stream Characteristics Sampawams Creek Predicted Stream Characteristics Skookwams Creek Predicted Stream Characteristics Willets Creek Page No. I-1-2 I-2-2 II-l-8 II-l-9 II-l-10 II-l-ll II-l-12 II-l-13 II-2-4 II-2-5 II-2-6 II-2-7 II-2-8 II-2-9 II-2-10 II-2-11 II-2-13 II-2-15 II-2-16 I I I I I I I I I '1 I ! [ I I I I I I Figure No. II-2-11 II-2-12 II-2-13 II-2-14 II-2-15 II-2-16 II-2-17 II-2-18 II-2-19 II-2-20 II-2-21 II-2-22 II-3-1a II-3-1b III-3-1 III-3-2 III-3-3 III-3-4 LIST OF FIGURES (cont'd) Predicted Stream Characteristics Trues Creek Predicted .Stream Characteristics Thompson's Creek Predicted Stream Characteristics Cascade Lakes Predicted Stream Characteristics Lawrence Creek Predicted Stream Characteristics Watchogue Creek Predicted Stream Characteristics Penataquit Creek - East Branch Penataquit Creek - West Branch Predicted Stream Characteristlcs Awixa Creek . · Predicted Stream Characteristics Orowoc Creek - West Branch Predicted Stream Characteristics Orowoc Creek - East Branch Predicted Stream Characteristics Champlin Creek Predicted Stream Characteristlcs West Brook Predicted Stream Characteristics Connetquot River Calculated Increase in Bay Salinities Due to the No-Action Sewering Stresses Calculated Increase in Bay Salinities Due to the No-Action Sewering Stresses Impacts on Stream'Ecological Values Impacts on Stream Aesthetic Values Impacts on Stream Recreational Values Impacts on Residential Properties Values Page No. II-2-17 II-2-18 II-2-19 II-2-20 II-2-21 II-2-22 II-2-23 II-2-24 II-2-25 II-2-26 II-2-27 II-2-28 II-2-29 II-3-5 II-3-6 III-3-4 III-3-8 III-3-13 III-3-19 I I I I I I I I I I I I I I I I I I I MILESTONE II - SUMMARY The objective of this milestone was to present the pre- dicted environmental and hydrological impacts of the sewering program as they relate to the 22 streams in the study area and to the salinity of Great South Bay. Results are as follows: · Groundwater Table - The U.S. Geological Survey's sub- regional three-dimension groundwater model showed a maximum water-table drop of 7 feet near the Nassau/Suffolk border at the Long Island Expressway; a minimum of 0.7 feet in Amityville; no change in the northeastern part of the study area (Great River, Central Islip); and a 0.7-foot change at Heckscher State Park. The greatest change is nearest the Nassau/Suffolk County line, reflecting the additional effect of the Nassau County sewering program. Changes were minimal east of the Carll's River. · Streamflow - A total flow loss of 34 cfs (22 MGD) was predicted, with the percentage of flow loss ranging from 75 percent for Amityville Creek to <1 percent at Connetquot River. · Stream Length - Four streams showed shortenings of 1,000 feet or more, but in general most streams were predicted to still have enough water to sustain the wetland and upland communities. Shortenings will occur from the northern portion of the streams and extend south. · Underflow - A change of only 6.7 cfs (4.4 MGD) was noted for the study area. I I I I I I I I I I I I I I I I I I ® Water Quality - Due to the great variability of ground- water quality, both area wide and on site, very little change in stream quality was predicted. ® Eutrophication - No evidence was shown that increased residence time will intensify nuisance algal bloom conditions. ® Salinity - Maximum increase of one part/thousand in the open portion of the bay, near shore, quickly dropping to 0.5 ppt at the Nassau/Suffolk border and Connetquot River on the east. Some higher increases did occur within the inlets and the mouths of several creeks. · Streambed Exfiltration - A maximum conservative design exfiltration loss, based upon a water table 4-6 feet below the streambed, of 7.44 x 10-4 cfs per foot of streambed was observed. · Recreation - Impact to recreational areas of only five streams was noted. · Aesthetics - This factor appears most sensitive to streamflow reductio~ as changes in stream and lake geometry will affect local scenic vistas. · Ecology - Wetlands show little impact and will gradually change their vegetation to accommodate any change in ground- water levels. · Property Value - Small to negligible changes are predicted. · Lakes - Play an important role in the environmental ratings, as they support and provide aquatic habitats, recre- ational areas and aesthetic vistas. 2 I I I I I I i I I I I I l I I I I I I · Time - The streaa%flow and water table for no-action results will reach 90 percent of the predicted values five (5) years after maximum hook-up is achieved (five years from start- up of the district). · Ranking - Streams in the western part of the Southwest Sewer District receive the most impact. Results for greatest _ to least ~mpacted are: !. Amityville Creek 2. Carll's River 3. Woods Creek 4. Santapogue Creek 5. Neguntatogue Creek 6. Lawrence Creek 7. Willets Creek 8. Great Neck Creek 9. Sampawams Creek 10. Cascade Lakes 11. Watchogue Creek 12. Strong's Creek 13. Trues Creek 14. Orowoc Creek - West Branch 15. Penataquit Creek 16. Connetquot River 17. Champlin Creek 18. Orowoc Creek - East Branch 19. West Brook 20. Awixa Creek 21. Skookwams Creek 22. Thompson's Creek The EPA must now make recomendations to the County on whether mitigation is needed for streams and/or the bay. If needed, specific streams are to be recommended by EPA. The County will then proceed with Milestone III to prepare a mitigation plan. In the event that no mitigation is required, the project will terminate. effects of the streamflow. The County will continue to monitor the sewering program on the groundwater and CHAPTER I. INTRODUCTION Section 1 - Background 1.0 Introduction . 1.1 Results of Milestone I 1.2 Ratings from Milestone I 1.3 Mitigating Alternatives 1.4 Public Participation Section 2 - Objectives 2.0 Discussion . Page No. I-l-1 I-1-3 I-1-5 I-1-6 I-1-6 I-2-1 I I I I I I I I I I I I I I I I I I SECTION 1 - BACKGROUND 1.0 Introduction The United States Environmental Protection Agency (EPA) has mandated that Suffolk County prepare and execute a study to determine the primary and secondary environmental effects of sewering in southwestern Suffolk County. This project is called the Suffolk County Flow Augmentation Needs Study (FANS). The major purpose of FANS is to determine whether it is necessary to moderate possible declines in streamflow and lake levels in the study area (see Figure I-l-l) in order to coun- teract any effects of sewering and to prevent adverse environ- mental consequences. A cost-effective plan will be developed using inputs from the general public and other governmental agencies. FANS is to be completed by July, 1981. Seventy-five percent of the study's cost is being funded by the EPA. New York State and Suffolk County share the remaining 25 percent of costs of the $3.7 million study. Principal features Of the study include the creation of a groundwater model by the U.S. Geological Survey to determine future stream conditions; an environmental inventory of the existing conditions of the wetlands, fish and wildlife in the study area by Pandullo Quirk Associates; and modeling of the streams, several lakes and Great South Bay by Tetra Tech, Inc. I-l-1 I I I I I I I I I I I I I I I I I I I H U LONG ISLAND SOUND A ZAHNS AIRPORT zl OF STUI~ i~- DEER PARK AIRPORT GREAT SOUTH I-1-2 M ] T H?F O 'HWEST SEWER ,ISTRIC'I P $0~ I I I I I I I I I I I I I I I I I I I Finally, a separate study of the impact of reduced stream flows on the salinity of Great South Bay is being undertaken by EPA. The project is divided into three milestones: Milestone I evaluated the existing conditions; Milestone II determined the effects of sewering (the no-action alternative); and Mile- stone III will present, if needed, a plan to alleviate the problems caused by the lowering of the groundwater table. 1.1 Results of~Milestone I The stream ranking procedure relied on an environmental quality-of-life index compiled for each stream. The environ- mental features of each stream--specifically, the ecology, aesthetics, recreational, socio-economic (property value) and water quality--were quantified for the purpose of providing an overall rating for each stream. The ratings can be assem- bled from highest to lowest to present the streams in order based on index parameters. Specifically, in ecology, the study inventoried and evaluated the woodland and wetland areas to characterize the plants and wildlife communities around each stream. Informa- tion was also collected for the aquatic communities, as well as migratory wildfowl. The data was assembled to comprise the ecological quality of each stream basin. In aesthetics, data was collected on visual stream char- acteristics including vegetation, water color, debris, natural conditions versus man-made conditions, and the presence or I-1-3 I I I I I I I I I I I I I I I I I I absence of different types of vegetation. Citizens were also asked to judge various types of scenes in order to measure their feelings on visual character. These two aspects were combined statistically to present the visual or aesthetic rat- ing for each stream. In recreation, all recreational locations adjacent to streams were identified. Data was collected on the types of recreational activities occurring at each area (fishing, boat- ing, swimming, etc.), as well as activities not relating to the presence of water (picnicking, bicycling, strolling and sporting activities). Usage at each facility was then sur- veyed, and the analysis produced a recreational rating for each stream. The socio-economic study concentrated on residential property values. Tax records were used to obtain information on residential properties adjacent to each stream (acreage, house size, age of home). A statistical procedure was followed to produce a predicted value for each home which could then be compared to the actual assessed evaluation. The total property value for each stream was then computed and ratings produced. For water quality, sampling was performed on all streams, and a standard system was used to numerically rank the water quality of each stream. Seven specific water quality parameters were used, and a rating was produced for each stream. I-1-4 I I I I I 1.2 Ratings from Milestone I The results of the above work produced the following: Environmental Index 1. Carll's River 8.46 2. Sampawams Creek 7.54 3. Connetquot River 7.23 4. Champlin Creek 6.45 5. Orowoc Creek - East Branch 5.83 6. Orowoc Creek - West Branch 5.47 7. Cascade Lakes 5.36 8. Santapogue Creek 5.33 9. West Brook 5.30 10. Penataquit Creek 4.91 11. Willets Creek 4.62 12. Awixa Creek 4.61 13. Trues Creek 4.60 14. Amityville Creek 4.60 15. Lawrence Creek 4.57 16. Great Neck Creek 3.91 17. Neguntatogue Creek 3.76 18. Skookwams Creek 3.31 19. Woods Creek 3.24 20. Thompson's Creek 3.04 21. Strong's Creek 3.03 22. Watchogue Creek 2.28 Milestone I determined that the first nine streams are the most important, and in Milestone II, a stream water quali- ty model was produced for each of them. Amityville Creek was added as a tenth stream, because it is the westernmost stream in Suffolk County and will receive the greatest hydrogeological impact from the sewering of Suffolk County Sewer District No. 3-Southwest and Nassau County Sewer District No. 3. All the streams were reviewed for the impact of sewering and the change in the environmental index. This change pro- duced a list of streams, at the end of Milestone II, which will be candidates for stream augmentation. Cost of alternatives I-1-5 !1 I I I I I I I I I I I I I I I I I I and cost effectiveness will determine the final stream recommendations. 1.3 Miti~atin~ Alternatives Various methods were reviewed as possibilities for future use in mitigating streamflow declines. Twenty-six alternatives were presented and investigated for technical and practical relevance. From this group, the following alternatives were selected to receive further consideration in Milestone II. Reduce water use. Restrictive barrier within the aquifer. - Relocate public water supply wells. - Recirculation of streamflows. - Stream and/or lake impoundments. - Addition of flows to streams. - Rehabilitate streambeds. - Restrict ocean flow into bay. - Well discharge to bay. 1.4 Public Participation Various types of public information and public involve- ment have been used in the project including newsletters, speakers, public agency meetings and public hearings. Each milestone will produce a report(s) for review and comment by the public and by professionals. Citizen comment and concern will be considered in all phases of the project. I-1-6 I I I I I I I I I I I I I I I I I I I SECTION 2 - OBJECTIVES 2.0 Discussion This report presents the results of the sewering impact on the environmental and hydrologic features of the 22 study area streams (see Figure I-2-1). 'These are the predicted re- sults should no mitigation be undertaken (no action). It should be noted at the outset of this report, that these are only predicted results, based on the use of the most up-to- date analytical tools. What actually will occur can only be found by observing the real system under actual recharge and sewering conditions. Only by closely monitoring the ground- water table, streamflow, headwaters and ecological changes can actual comparisons to the predicted conditions be performed. The report presents the predicted results to EPA for their review and recommendation. Upon receipt of instruction to mitigate a stream(s), Suffolk County will proceed with Milestone III, which will present a mitigation plan. The results of the Great South Bay model are also included and have been sent separately to EPA's consultant, WAPORA. They will report to EPA on potential salinity impact to the hard clam, whereupon EPA will also recommend whether mitiga- tion is needed for the bay. Should mitigation of the bay be required, Suffolk County wili prepare a mitigation plan as part of Milestone III. In the event that no mitigation is required, the project will terminate with Milestone II. I-2-1 I I I I I I I I I I I I I I I I I I I HUNTINGTON STREAMS FOR STUDY {KEY): Amityville Creek BABYLON / Amifyvil[e Brentwood Greot River CHAPTER II. MODELING RESULTS Section 1 Groundwater Model 1.0 Introduction . 1.1 Water-Table Impact . 1.2 Streamflow Impact 1.3 Headwaters Stream Shortenings 1.4 Underflow to Bay . Section 2 - Stream Modeling 2.0 Introduction 2.1 Changes in Stream Geometry 2.2 Lake and Pond Changes 2.3 Water Quality Section 3 - Great South Bay Model 3.0 Discussion Section 4 - Streambed Exfiltration Page No. II-l-1 II-l-2 II-l-14 II-1-29 II-l-31 II-2-1 II-2-1 II-2-31 II-2-31 II-3-1 4.0 Discussion II-4-1 I I I I I I I I I I I I I I I I I I I SECTION 1 - GROUNDWATER MODEL 1.0 Introduction This section of the Milestone II report will present the results of the USGS groundwater modeling effort. The work con- sisted of producing a digital three-dimensional model of the groundwater system in the study area with a grid spacing of 1,000 ft. (north/south) by 2,000 ft. (east/west). The steady- state condition used to represent the long-term hydrologic conditions of the groundwater table was based on the average value using 1943-1972 observations. The March, 1972 potentio- metric surface was used to establish steady-state conditions for the Magothy aquifer. The grid spacing indicated above was needed to allow for area-specific interpolation of water-table changes and to represent the streamflow in more detail. To determine steady-state conditions for all 22 streams, correlation curves were established using continuous discharge records from seven streams and partial gauging records from others. The steady-state average was established, utilizing data from 1968-75. The results of both steady-state and no-action modeling represent a considerable amount of computer output, which re- quires some study before results and impacts become apparent. In the succeeding sub-sections, tables, graphs and maps have been inserted to present the information, both in summary and in detail. Before proceeding, it is suggested that the reader II-l-1 I I I I I I I I I I I I I I I I I use the map contained in the back pocket of the report as a guide. The map shows the model grid spacing, shoreline, streams, the stream gauging stations and the shallow monitor- ing wells used for the FANS project. Results, tables, etc., can be best understood by regularly referring to this map. 1.1 Water-Table Impact The succeeding pages contain the following information: ® Table II-l-1 - Estimated water levels for FANS wells. Ail the wells shown on the map with their estimated steady- state water levels (in feet above mean sea level) and the predicted change. These wells should be continued and read regularly to establish a permanent water-table record for the Southwest Sewer District. · Table II-l-2 - Selected cross sections. Three sections (A-A, B-B, C-C) have been chosen to represent water-table changes in the north-south direction at several points in the study area. Section A-A in the western part of the study area shows a maximum water-table change of 6.2 feet near the Long Island Expressway (LIE), decreasing to 0.7 feet at Montauk Highway. Section B-B follows the Carll's River system and generally shows only slight impacts ranging from 2.6 feet at the LIE to 0.3 feet at Montauk Highway. Section C-C, in the eastern part of the study area, follows the Connetquot River system and shows no change at the LIE and only a slight change (0.7 feet) at Heckscher State Park. II-l-2 I ! I Two sections (D-D, E-E) have been chosen to represent the water-table changes in the e~st-west direction at two points in the study area. Section D-D represents the change antici- pated in the southern portion of the study area (Montauk High- i way), with changes of only 0.7 feet in Amityville to zero in the Great River area. Section E-E represents changes in the I northern portion of the study area, ranging from 3.8 feet in the west to 0.3 feet in the east. I · Figures II-l-1 through II-l-5 - Graphical representa- i tion of the changes in water table indicated in Sections A-A, B-B, C-C, D-D and E-E. i I ® Figure II-l-6 - Contour map of the predicted drawdowns due to a loss from sewering. It should be noted that the maxi- mum impacts to the water table are in the western portion of i i the county, primarily because of the additional effect of the larger sewering program of Nassau County. Also noted should be the minimal effects east of Carll's River. !l i I II-l-3 I I I I I ! I I I I I I I I I I I I TABLE II-l-1 ESTIMATED WATER-LEVEL ELEVATIONS FOR FANS WELLS Estimated Predicted Well Steady State Change No. Elevation Ft. Ft. 64319 73.0 6.2 64320 67.2 6.9 64848 47.9 3.8 64851 37.7 4.3 64218 22.6 6.2 64226 23.0 2.5 64215 18.9 2.8 64575 15.9 1.8 64574 13.1 1.1 64571 7.9 .7 64216 3.3 .5 64565 10.5 1.3 66565 16.1 1.3 64213 10.8 1.3 64857 18.4 1.0 66567 13.4 1.0 64212 3.9 .7 64853 23.0 1.1 64856 13.8 .8 64560 24.3 1.4 64852 23.3 1.6 64556 12.1 1.0 64210 6.2 .7 64316 74.5 2.6 56347 52.5 1.0 56349 51.7 .7 56348 52.2 1.0 56351 44.3 1.3 56350 45.3 .5 63761 41.2 .5 64308 40.7 .3 56352 37.1 .3 56354 34.4 1.3 64224 29.5 .7 56361 19.8 .3 56362 16.2 1.3 64554 7.2 .3 64222 29.7 ,5 56358 25.1 .3 64202 16.4 .7 56357 17.4 .3 56359 17.4 .3 56360 16.4 .3 64196 11.2 .3 56363 10.5 .3 64195 6.2 .3 64313 66.9 1.6 56356 26.9 o7 64192 10.5 .7 66576 31.2 .7 64191 18.4 1.0 66578 4.6 0 64311 50.3 1.0 Estimated Predicted Well Steady State Change NO. Elevation Ft. Ft. ~ ' 41.3 .3 63741 36.7 .3 63747 37.1 .5 64190 28.2 1.5 64539 21.6 1.3 64535 13.8 1.0 64540 35.6 1.1 64186 6.2 .7 64532 12.0 1.0 66580 10.7 .8 64184 10.5 .6 64314 64.1 1.0 63854 15.4 1.0 63855 12.5 .7 63852 31.5 1.0 63853 27.6 .8 63851 27.6 .3 63845 4.6 .3 63849 19.0 .3 63841 5.2 .3 64530 6.7 .3 63823 34.8 .7 64525 17.4 .3 66587 11.8 .3 66586 9.2 .5 64507 28.2 .3 64523 15.1 .3 63820 35.3 .3 66589 12.8 .3 64521 14.1 .3 63840 8.2 .2 63835 6.6 .3 63837 26.2 .3 63836 14.1 .3 64519 7.2 .3 64510 31.2 .7 64511 26.6 .5 64513 18.7 .5 64517 11.5 .3 64520 7.5 .3 64516 14.8 .8 63832 3.9 .5 63830 12.0 1.8 63828 4.9 .7 63827 6.6 .7 63825 5.7 .5 66593 7.5 0 63814 15.1 0 63813 25.4 .3 63811 23.0 63810 23.3 0 64503 36.9 0 64502 40.3 0 63806 49.5 0 II-l-4 iI I I I i I i I i I I I il I I I I I ! TABLE II-l-2 SELECTED CROSS SECTIONS Section A - A Well Steady State Predicted Change; No. Elevation Ft. in Elevation Ft. 64571 7.9 .7 64574 13.1 1.1 64575 15.9 1.8 64220 23.0 2.5 64320 67.2 6.2 64319 73.0 6.2 Section B - B Well Steady State Predicted Change No. Elevation Ft. in Elevation Ft. 64195 6.2 .3 64196 11.2 .3 56360 16.4 .3 56359 17.4 .3 56358 25.1 .3 64222 29.7 .5 63761 41.2 .5 56350 45.3 .5 56348 52.2 1.0 64313 66.9 1.6 64316 74.5 2.6 II-l-5 I I I I I I I I TABLE II-l-2 (cont'd) Section C-C Well Steady State Predicted Change No. Elevation Ft. in Elevation Ft. 63828 4.9 .7 63827 6.6 .7 63825 5.7 .5 63814 15.1 0 63813 25.4 .3 63810 23.3 0 64503 36.9 0 64502 40.3 0 63806 49.5 0 Section D-D Welt Steady State Predicted Change No. Elevation Ft. in Elevation Ft. 64571 7.9 .7 64565 10.5 1.3 64213 10.8 1.3 64556 12.1 1.0 56363 10.5 .3 64196 11.2 .3 64535 13.8 1.0 64532 12.0 1.0 63854 15,4 1.0 63845 4.6 .3 63841 5.2 .3 64530 6~6 .3 63840 8.2 .2 64517 11.5 .3 66593 7.5 0 I I I I I I ! i I II-l-6 I I ! I ! i I I TABLE II-l-2 (cont'd) Section E-E V;eH S[eady Stale Predic[ed Change No. Elevation Ft. in Elevation FI. 64848 47.9 3.8 56351 44.3 1.3 64308 40.7 .3 63761 41.2 .5 64543 41.3 .3 63823 34.8 .7 63820 35.3 .3 64510 31.2 .7 63813 25.4 .3 ! I I I I I I I I I I II-l-7 8-I-II GROUNDWATER ELEVATION (FEET ABOVE MSL) LONG ISLAND EXPRESSWAY 64519'~WELL NUMBERS /// 64520 /// ' · iI/11/~~ iiiii -- / SOUTHERN STATE PARKWAY // SUNRISE HIGHWAY 0 // ~ 64574 64571 SHORELINE I I I I I I I i ! I i i I I I 6-I-II GROUNDWATER ELEVATION (FEET ABOVE MSL) ~ 0 0 0 0 0 0 64316"~'--WELL NUMBERS ' // U LONG llSLAND. EXPRESSWAY 64515 / 56S48 56550 // 65761 // SOUTHERN STATE PARKWAY ~ ~ 64222 Z -'1 56558 ~/ m /" ~,0 56559 SUNRISE HIGHWAY (/1 0 m C 56:560 m~ "r- ~,96 ~ --~ MONTAU~ H,GHWAY~ ~ I" SHORELINE I11 I I I I I I I I I, I I i 1 I ! ! ! ! Z OI-I-II GROUNDWATER ELEVATION (FEET ABOVE MSL) o o o o o~.__~__~,_...~__,~..~_o ,o .'7' /WELL NUMBERS I 63e08 / ' 64502 /LONG ISLAND EXPRESSWAY I I 63810 I 63813 I , ! ! 6$BZ, .ONTAUK HIGHWAY ~ "~ 63828 iHORELINE m I I TI-T-II GROUNDWATER ELEVATION (FEET ABOVE MSL) 64571 '~ \AMITYVILLECREEK WELL '",~ NUMBERS "., ~ 64565,~'"' ~ ~ STRONGS CREEK 64213 \, ~ * x~ LAWRENCE CREEK 65845 ~ ~ ~ 6~841 ~ Z ~ 64517 ~ m ,Y ~ .,.,, . .,s. ,.oo, c,,,, ~ GROUNDWATER ELEVATION (FEET ABOVE MSL) 0 ~ 0 64848~.-.---WELL 56351 64308 63761 64543 63823 63820 64510 NUMBERS ;~S RIVER I SAMPAWAMS CREEK ~ OROWOC CREEK CREEK WEST Z'-I II i I I I I I ! I! ! I i I I I I I FIGURE I I-1-6 PREDICTED DRF~WDOWNS DUE TO LOSS OF RECHARGE FROM SEWERING 6 5 ~ ~ 2 POINT /SUFFOLK COUNTY LINE I I I I I I I I I CONTOUR INIERVAL i FOOT I I I I I I I I I I I I I I ,I ! 1.2 Streamflow Impact The succeeding pages contain various tables presenting the streamflow and stream shortenings. · Table II-l-3 - Predicted total steady-state, no-action flows and shortenings. This table shows each stream's steady state, no action and predicted change in base flow, plus the approximate shortening. Since the stream shortening can only be predicted to be 0 or 1,000 feet in length (size of model grid), a value of 500 feet was added to take into account any partial shortening of the next node. Stream length changes shown with an asterisk are predicted to flow in the most northerly stream node for both steady state and no action. Total predicted streamflow change is 34.07 cfs (22 MGD). · Table II-l-4 - Streamflow changes as estimated for gauging stations along each stream. The steady-state and no- action flows plus the cumulative flow are represented. Gaug- ing stations are located on the large map referred to earlier. Gauging should also continue on specific streams to establish a permanent record of flow and flow change. The streambed elevations were obtained from surveying profiles produced for each stream. They were used as control elevations by the USGS to establish conditions of flow or no flow in the stream transient model. II-l-14 TABLE II-l-3 PREDICTED TOTAL STEADY-STATE, NO-ACTION FLOWS AND STREAM SHORTENING Stream Name Amityville Creek Woods Creek Great Neck Creek Strong's Creek Neguntatogue Creek Santapogue Creek Steady-State Average Baseflow (cfs) 2.66 2.06 2.25 1.60 3.54 7.9 Steady-State No-Action Baseflow (cfs) .69 1.26 1.0 .84 1.27 3.27 Predicted Change in Baseflow (cfs) 1.97 .8 1.25 .76 2.27 4.63 7.96 4.64 .13 .95 .84 .11 .51 .18 .19 2.53 .29 1.25 .25 1.95 .22 .39 Carll's River Sampawams Creek Skookwams Creek Willets Creek Trues Creek Thompson's Creek Cascade Lakes Lawrence Creek Watchogue Creek Penataquit Creek Awixa Creek Orowoc Creek-West Orowoc Creek-East Champlin Creek West Brook Connetquot River 23.3 10.07 .99 2.24 2.23 1.40 2.0 .70 .90 6.30 1.55 5.81 3.22 7.08 3.39 34.24 15.34 5.43 .86 1.29 1.39 1.29 1.49 .52 .71 3.77 1.26 4.56 2.97 5.13 3.17 33.85 Approximate Shortening of Stream Length (ft.) 4000-4500 2000-2500 2000-2500 East 1000-1500 West 5000-5500 TOTALS 125.43 *See explanation on page II-l-14 91.36 II-l-15 34.07 I I I I I I I I I I I I I I I I I FANS GAUGII~G STA~ ION 1-2 1-3 1-4 1-5 1-6 1-i0 1-12 2-1 2-2 LOWE ST ~ LEVATION 6.52 5.39 4.66 4.27 2.93 1.65 1.65 0 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREA~"LOW A~ityvill e Creek STEADY-STATE FLOW (¢fs) .31 .34 .33 .33 .34 .30 .29 .41 cUMIILATIVE STEADY-STATE FLOW (cfs) .31 .65 .93 1.31 1.65 1.95 2.24 2. 66 ' NO-ACTION FLOW (Cf S) 0 0 0 0 .13 .12 .15 .25 C~U brULAT I ~ IiO -D CT I ON FLOW (cfs) 0 0 0 0 .17 · 28 .43 .69 3-1 2.16 .41 .41 .12 .12 3- 2 .88 .68 1.09 .36 .47 3-2.5 .79 .82 1.91 .54 .75 3-3 3-7 0 .21 2.25 .25 .996 II-l-16 Great i~eck Creek woods Creek 2.56 .56 .56 .24 .24 .61 .68 1.24 .42 .67 .18 .82 2.06 .59 1.26 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREA~LOW Strongs Creek FA~S LOWEST STEADY-STATE CUMULATIVE NO-ACTION GAUG/~G STREA~iBED FLOW STEADY-STATE FIDW STATION EI/~VAT ION (cf s) FLC,W (cfs) (cf s) 4-1 1.59 .61 .61 .25 4-2 .98 .46 1.07 .25 4-3 0 .53 1.60 .35 4-4 Neguntatogue Creek 5-1 6.8 .17 .17 0 5-2 5.91 .39 .58 0 5.18 .39 1.0 .09 5-3 3.78 .48 1.48 .14 5-5 3.02 .43 1.9! .13 5-6 2.01 .40 2.32 .17 5-7 1.31 .40 2.72 .23 5-8 .15 .44 3.17 .27 5-9 0 .37 3.54 .23 S anta~oo~ue Creek 6.9 .42 .42 0 5.73 .45 .67 .14 6-5 5.15 .43 1.31 .19 4.51 .43 1.74 .21 6-11 8.35 .43 .43 0 6-12 7.56 .43 .87 0 6-13 6.61 .51 1.27 .08 6-]4 6.16 .42 1.69 .14 II-l-17 CUMb~LAT IVE ~O-AC~ ION FLOW (cfs) .25 .50 .84 0 0 .lO .25 . 37 .45 .77 1.04 1.27 0 .17 ! West .37 ' Branch .58 I o 0 East Branch .11 .25 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREAMFLOW Santapogue Creek (cont'd) FANS LOWEST STEADY-STATE CUMULATIVE GAUGING ST~EAMBED FLOW STEADY-STATE STATION ELEVATION (cfs) FLOW (cfs) 6-15 5.55 .40 2.09 6-16 4.63 .42 2.51 6-17 4.11 .40 2.92 6-7 West 2.71 .93 3.85 6-18 East 6-8 West 1.83 .81 4.66 6-18 East 6-9 West 1.10 .92 5.58 6-20 East .09 .39 7.71 6-21 0 .19 7.9 Carll' s River 7-1 16.76 .75 .75 . ~36 7-2 7-3 15.24 7-4 14.02 7-6 7-7 12.74 7-8 12.10 11.34 7-9 7-10 10.55 7-11 10.0 II-l-18 NO-ACTION FLOW (cfs) .,. .17 .21 .23 .63 .55 .26 .25 · 14 C~UJLAT IVE NO-ACTION FLOW (cfs) .40 .64 .86 1.49 2.04 2.30 3.13 3.27 .36 · 60 1.35 .31 .69 .63 1.98 .36 1.05 .65 2.63 .35 1.40 · 60 3.23 .40 1.79 .60 3.84 .42 2.33 .60 4.45 .42 2.63 .60 5.05 .42 3.06 I I ! I i I I I ! I I I I I I I I I I FANS LOWEST GAUGING STIAEAMBED STATION ELEVATION 7-12 10.0 7-13 10.0 10.0 7-18 7.86 7.32 7-21.0-. 7 6.86 6.25 7-22 5.33 4.60 4.18 9.75 7-27 8.14 7-28 7.65 6.95 7- 31 6.64 8.84 7.62 7.32 7-34 5.73 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREAMFLOW Carll's River (cont'd) STEADY-STATE CUMirLATIVE FLOW STEADY-STATE (cfs) FLOW (cfm) .60 5.65 NO-ACTION FLOW .43 .60 6.26 .43 .60 6.86 .42 .60 7.46 .40 .60 8.07 .38 .60 8.70 .38 .63 9.30 .39 .60 9.90 .37 .65 10.56 .38 .51 11.07 .27 .24 ~.24 .18 .63 .87 .50 .63 1.50 .50 .60 2.1 .47 .82 5.05 .64 .75 .75 .49 .70 1.45 .46 .68 2.13 .39 .65 5.70 .48 II-l-19 CUI~/LATIVE NO-ACTION FLOW (cfs) 3.48 3.92 4.35 4.75 5.13 5.51 5.90 6.27 6.65 6.92 .18 .68 1.18 1.65 3.41 .49 .95 1.12 3.88 TkBLE II-l-4 STEAl]Y-STATE AND NO-ACTION STREA~LOW Carll's River (cont'd) FA~S LOWEST STEADY-STATE CUMULATIVE GAUGING STREAMBED FLOW STEADY-STATE STATION ELEVATION (cfs) FLOW (cfs) 5.06 .60 6.3 4.63 .65 6.96 4.18 .63 7.58 7-26 4.18 1.26 19.91 7-35 3.51 .60 20.52 7-39 2.62 .60 21.12 2.19 .63 21.74 7-40.0-.5 1.98 .63 22.38 7-41 1.98 .60 22.98 .32 23.3 Sampawams Creek 8-1 13.32 .50 .50 8-2 12.71 .50 1.00 8-2.5 12.3 .45 1.45 11.58 .47 1.92 11.15 .55 2.47 8-3 11.16 .53 3.00 i0.73 .45 3 · 46 8-9 8.63 .45 3.9 ~ '-~ .55 4.46 8-10 ' "~ 8-11 6.61 .50 4.96 II-1-20 NO-ACTION FLOW .43 .45 .45 .98 .45 · 45 .48 .49 .45 .10 · 33 ,36 ,31 .32 .38 .32 .24 .23 .23 .07 CUMULATIVE NO-ACTION FLow (cfs) 4.31 4.76 5.21 13.12 13.56 14.02 14.50 14.99 15.45 15.34 .33 .70 1.01 1.34 1.72 2.04 2.27 2.50 2.73 2.80 I I I I I i I I I I I I I I I I I I F~S ~UG~G STATION 8-12 8-15 8-16 8-19 8-20 8-21 ~25 9-1 9-2 9-2.5 9-3 10-2 10-3 10-4 LOWEST STP~EA~iBED RT,~VAT ION 6.28 6.28 4.51 4.08 3.17 2.29 2.07 1.65 1.52 0 0 7.07 6.25 5.36 TABLE II-l-4 STEADY-STATE AND NO-ACTION STBEAMFLOW Sampawams Creek (cont'd) STEADY-STATE CUMULATIVE FLOW STEADY-STATE (cfs) FLOW (cfs) NO-ACTION FLOW (cfs) CUMULATIVE NO -ACT ION FLOW (cfs) 4.94 .13 .&2 0 0 3.96 .14 .52 0 0 3.02 .12 .61 .05 .05 .49 .49 .43 .43 .49 .99 .43 .86 Willets Creek .095 .10 0 0 .16 .21 0 0 .14 .32 0 0 II-l-21 Skookwams Creek .~5 5.44 .06 2.86 .45 5.87 0 2.86 .43 6.30 .09 2.95 .45 6.75 .20 3.12 .43 7.2 .23 3.35 .43 7.6 .24 3.59 .42 8.1 .28 3.87 .43 8.49 .33 4.20 .47 8.96 .39 4.59 1.11 10.07 .84 5.43 I I I I i I I I I I ! I ! I I I I I FANS LOWEST GAUGING STREAMBED STATION RT,~rv-AT ION 10-5 2.38 10-6 1 · 34 10-7 10-13 0 11-1 3.78 11-2 2 · 59 11-2.5 1.80 11-3 1.22 11-7 .67 11-5 11-10 0 2.26 12-1 1.95 12-2 .88 12-3 0 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREA~LOW Willets Creek STEADY-STATE C~TIVE FLOW STEADY-STATE (cfs) FLOW (cfs) .13 .71 .12 .80 1.11 2.18 .06 2.24 (cont'd) NO-ACTION FLOW (cfs) .07 · 36 .75 .05 CUMULATIVE NO-ACTION FLOW (cfs) .12 .49 1.24 1.29 II-1-22 Thom~sons Creek .16 .16 .10 .10 .53 .69 .26 .36 .53 1.22 .45 .81 .17 1.40 .48 1.29 Trues Creek .36 .36 .16 .16 .36 .73 .20 .36 .34 1.07 .08 .44 .35 1.42 .26 .70 .38 1.80 .31 1.01 .43 2.25 .38 1.39 I I I I i I I I I I I I I I I I I I I FANS GAUGING STATION 13-1 13-3 13-9 14-2 14-3 14-6 14-615 15-1 15-2 16-2 16-3 16-4 16-5 16-6 16-10 LOWEST STREAMBED F.T,EVAT ION 3.35 2.65 1.95 2.58 1.83 2.62 0 9.24 6.86 6.04 4.42 3.17 8.02 6.22 5.58 5.00 3.99 3.17 2.26 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREAMFLOW Cascade Lakes STEADY-STATE CUMULATIVE FLOW STEADY-STATE (cfs) FLOW (cfs) NO-ACTION FLOW (cf s) CUMULATIVE NO-ACTION FLOW (cfs) .20 .20 .07 .07 1.08 1.78 .82 .89 .73 2.0 .06 1.49 Lawrence Creek .25 .25 .40 .70 .17 · 36 · 3O .41 Watchogue Creek .40 .40 .50 .90 Penata~uit Creek .50 .50 .24 .55 1.05 .28 .41 1.46 .27 .49 1.95 .33 .52 ~.47 .35 .33 .34 .21 .40 .73 .27 .40 1.13 .28 .38 1.51 .28 .38 1.89 .28 .38 2.27 .29 .79 5.53 .06 II-1-23 .17 .52 .3O · 71 .24 .52] West · 78 / Branch 1.11 ! 1.46 · 76] Branch 1.02 1.32 1.61 3.14 I I I I I I I I I I I I I I I I I FANS GAUGING STATIC~ 16-11 16-12 17-3 17-4 17-5 17-6 17-7 17-8 17-9 17-10 18-1 18-2 18-3 18-4 18-5 18-6 LOWEST STREAMBED ELEVATION 1.13 0 5.82 5.33 4.21 3.2 1.83 1.25 .43 11.13 11.09 10.06 9.08 8.41 7.62 6.86 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREAMFLOW Penatac~uit Creek (cont'd) STEADY-STATE FLOW (cf s) CUMULATIVE STEADY-STATE FLOW (cfs) NO-ACTION FLOW (cfs) CD~4ULATIVE NO-ACI'ION FLOW (cfs) .15 .15 .11 .11 .25 .4 .19 .50 .22 .63 .17 .47 .21 .84 .17 .65 .21 1.05 .17 .~2 .21 1.26 .18 1.©1 .28 1.55 .26 1.26 Orowoc Creek West .24 .24 .20 .20 .39 .63 .32 .~9 .42 1.05 .36 .~8 .41 1.46 .34 1.22 .44 1.90 .36 1.58 .41 2.3 .32 1.99 .42 2.73 .34 2.26 II-1-24 Awixa Creek .38 5.92 .31 3.38 .38 6.30 .33 3.77 I I I I ! ! I I I I I I I I I I I I FANS GAUG~G STATION 18-7 18-8 18-9 18-10 18-11 18-12 LOWEST STREAMBED ELEVATION TABLE II-l-4 STF~Y-STATE AND NO-ACTION STREAMFLOW Orowoc Creek West (cont'd) STEADY-STATE FLOW (cfs) CUMULATIVE STEADY STATE FLOW (cfs) NO-ACTION FLOW (cfs) CUMULATIVE NO-ACTION FLOW (cfs) 5.73 .39 3.12 .32 2.57 4.88 .45 3.57 .39 2.96 3.84 .45 4.03 .39 3.35 2.96 .45 4.49 .41 3.76 2.23 .45 4.94 .44 4.17 2.13 .41 5.35 .38 4.55 .47 5.81 .38 4.94 Orowoc Creek East 19-2 6.64 .38 .378 19-3 19-4 5.91 .32 .70 19-5 5.15 .38 1.08 19-6 19-7 4.02 .40 1.48 19-8 3.66 .32 1.81 19-9 3.11 .40 2.21 19-10 2.13 .35 2.56 .40 3.03 .30 · 26 · 30 .33 .27 .35 .30 .38 II-1-25 .30 .86 1.16 1.50 1.77 2.11 2.41 2.8 I I I I I I I I I I I I I I I I I I I FANS GAUGING STATION LOWEST STREAMBED ELEVATION TABLE II-l-4 STEADY-STATE AND NO-ACTION ST~EAMFLOW Cham~lin Creek STEADY-STATE FLOW (cfs) CUMULATIVE STEADY-STATE FLOW (cfs) NO-ACTION FLOW (cfs) .21 CUMULATIVE NO-ACTION FLOW (cfs) .21 20-1 8.81 .~7 .28 20-2 .75 8.34 .65 .92 .54 20-3 7.65 .62 1.54 .53 1.27 20-4 6.95 .69 2.23 .59 1.86 20-5 6.34 .69 2.93 .54 2.40 20-6 5.49 .62 3.55 .49 7.89 20-7 4.66 .65 4.20 .52 3.41 20-8 4.24 .58 4.77 .45 3.86 20-9 3.60 .60 5.37 .47 4.33 20-10 3.32 .60 5.97 .47 4.80 20-14 20-15 20-16 20-16.5 .60 6.58 .51 7.08 West BrOOk .29 .29 .69 .99 .48 1.46 .48 1.95 .99 2.93 .66 3.60 -20 3.39 II-1-26 21-1 3.75 3.26 2.80 2.29 1.77 1.77 .26 .O7 · 26 .63 .42 .47 .96 .65 -.22 21-2 21-6 21-10.5 5.06 5.13 .26 .89 1.32 1.78 2.74 3.39 3.17 I I I I I I I I I I I I I I I I i I FANS GAUGI}~G STATION 22-1 22-2 22-3 22-4 22-7 22-8 22-9 22-9.5 22-10 22-11 22-11.5 22-13 22-12 22-13.5 22-14 22-14.5 22-15 ,' 22-16 LOWEST STREAMBED ELEVATION 12.10 11.52 10.71 10.64 10.36 9.66 9.39 8.87 8.50 8.20 7.35 6.83 6.19 8.50 6.74 5.58 5.00 5.00 5.00 4.05 TABLE II-l-4 STEADY-STATE AND NO-ACTION STREAMFLOW Connet c~uot River STEADY-STATE CUMULATIVE FLOW STEADY-STATE (cfs) FLOW (cfs) .70 1.26 · 70 1.96 NO-ACTION FLOW (cfs) .70 1.26 CUMULATIVE NO-ACTION FLOW (cfs) .70 1.26 1.16 3.12 1.16 3.11 .79 3.91 .79 3.90 .70 4.61 .69 4.59 1.95 6.56 1.95 6.5~ .70 7.26 .69 7.23 1.63 8.89 1.61 8.~4 9.28 9.82 .90 9.75 .70 10.55 .68 10.43 1.18 11.69 1.14 11.57 1.21 12.40 1.20 12.77 2.04 14.95 2.03 14.80 .32 0.32 .30 2.14 2.47 2.07 1.67 19.09 1.65 1.86 20.95 1.83 .70 21.65 .69 1.44 23.09 1.43 1.49 24.57 1.48 II-1-27 .30 2.37 18.82 20.65 21.34 22.77 24.25 I I I I ! i I il I I I I I I I I I FANS GAUGING STATION 22-18 22-19 22-20 22-20.5 22-21 22-22 22-26 22-27 22-31 22-32 LOWEST STREAMBED ELEVATION TABLE II-l-4 STEADY-STATE AND NO-ACTION STREAMFLOW Connetc~uot River (cont'd) STEADY-STATE FLOW (~fs) CUMULATIVE STEADY-STATE FLOW (cfs) NO-ACTION FLOW (cfs) CU~/LATIVE NO-ACTION FLOW (cfs) .70 28.57 .69 28.21 1.39 29.97 1.39 29.60 1.29 31.26 1.28 30.89 1.90 33.16 1.89 32.78 .56 .01 .51 33.29 · 22 33.89 .21 33.50 .35 34.24 .35 33.~5 II-1-28 3.64 2.01 4.05 1.21 25.78 1.21 25.45 3.75 1.16 26.95 1.15 26.60 2.01 .93 27.87 .92 27.52 I 1.3 Headwaters - Stream Shortenings Changes in stream length have been detailed in Table I II-l-3. As indicated, four streams are specifically affected. I I i I i I I I I These shortenings are detailed as follows: · Amityville Creek - The average headwaters of Amityville Creek are predicted to recede 4000-4500 feet, which would be to a point between Austin Avenue and Maple Place. This deter- mination is referenced to the observed start of flow at Bayview Avenue. FANS headwaters data were observed to range from Bay- view Avenue to a point just below Pinehurst Park (4500 feet). This would indicate that the visual impact to the area may be no more than the annual fluctuation of the stream during aver- age years. · Neguntatogue Creek - The predicted no-action headwaters of Neguntatogue Creek will recede 2000-2500 feet, which would be between Daniel Street and Ithaca Street. This determination is referenced to the observed start of flow at Garden Place. Headwaters variation observed during FANS ranged from Garden Place to Newark Street in the south (1500 feet). The predicted impact would therefore be greater than the annual stream m m m fluctuation. · Santapogue Creek - The predicted no-action headwaters of Santapogue Creek, West Branch, will recede 2000-2500 feet, which would be between Newark Street and Daniel Street. This determination is referenced to the observed start of flow at m I Sunrise Highway. Headwaters variation observed during FANS ranged from Sunrise Highway to Daniel Street in the south II-1-29 I I I I I I I i i I I I I I I I I I I (2500 feet). This would indicate that the visual impact in the area may be no more than the annual fluctuation of the stream during an average year. The predicted no-action headwaters of Santapogue Creek, East Branch, will recede 1000-1500 feet, which would be bet- ween Shirley Street and Weber Avenue. This determination is referenced to observed start of flow at Tooker Avenue. Head- waters variation observed during FANS ranged from Tooker Avenue to Shirley Avenue (1500 feet); while during the drought of 1960, the headwaters were observed as far south as Railroad Avenue (5000 feet). $ Willets Creek - The predicted no-action headwaters of Willets Creek will recede 5000-5500 feet, which would be bet- ween Oakwood Avenue and Everdell Avenue. This determination is referenced from USGS assumed start-of-flow data at Garden Street. Headwaters locations observed during FANS ranged from Arcadia Avenue in the north to North Burling Lane in the south (4500 feet). North Burling Lane is approximately 1500 feet south of the predicted no-action headwaters location (Everdell Avenue). Although flow in Willets Creek was assumed by the USGS model to start at Garden Street, the maximum start of flow observed during FANS was Arcadia Street which is 2500 feet south of the USGS point. The predicted range of start of flow is already within the observed headwaters range. II-1-30 I I I I I i I I I I I I I I I I I I I 1.4 Underflow to Ba~ The steady-state underflow calculated for the area known as sub-region B (Amityville Creek to Greens Creek--east of the study area) was 92 cfs (59.5 MGD). The no-action underflow was 85.3 cfs (55.1 M~D), showing a change of 6.7 cfs (4.4 MGD). This change is small in comparison to the streamflow change of 34.07 cfs (22 MGD). The values are shown in Table II-3-1, as they were needed specifically for the Great South Bay model. II-l-31 I I I I I I I I I I I I I I I I I I SECTION 2 - STREAM MODELING 2.0 Introduction The material presented in Section 1 was used to project impacts on specific stream characteristics which were needed to produce the aesthetic, recreational, ecological, property value and water quality indicators for the EQOLI (environ- mental quality of life index). Specifically, the results, as detailed below, address: groundwater flow distribution; new width, depth, length and volume for each reach; new lake and pond characteristics (area, perimeter, volume, etc.); and water quality. 2.1 Changes in Stream Geometry The predicted resultant stream geometry, together with the streamflow for the particular stream reach, is shown for each stream on Figures II-2-1 through II-2-22. Relationships between the flow, depth or width of a stream are needed so the hydraulic characteristics of the stream can be expressed in terms of a single variable. The relationships developed are based on the field stream gauging data collected from September, 1978 to April, 1979 for each of the 22 streams. Each survey included measurements of depth, width, velocity and flow rate at different locations along the stream. Most of the stations are located approximately 1,000 feet apart starting at the headwaters and ending at Montauk Highway. II-2-1 I I I I I I I I il I il I I I I I il I I These hydrographic data are used to determine the rela- tionships between the flow and the hydraulic radius, and bet- ween the flow and the width. The mathematical expression H = A/P in which the hydraulic radius, H, is defined as A/P, where A is the crossrsectional area and P is the wetted perim- eter, is a convenient means for expressing the shape and the depth of a stream sec%ion. Empirical relationships have been found which agree that power functions using flow as the in- dependent variable will relate directly to width and depth-- Leopold and Maddock (1). They examined various rivers and developed empirical relationships between flow, velocity, depth and width. These relationships also took the form of power functions. O'Connor (2) has summarized the works of Leopold and Maddock and others on stream geometry, and found the power functions reliable. The relationships derived are thus: aQb d H = and W = cQ , where H is the hydraulic radius (equivalent to depth), W is the width, Q is the flow rate, a and c are the constants, and b and d are the exponents. In a recent theoretical study of gravel stream geometry, Chang (3) has deduced these empirical relationships from his rational model based on a resistance equation, a bed load equation and the minimum stream power condition. However, these empirical relationships can only be regarded as approximate, because natural channel sections where the streams are gauged'are difficult to control. In general, the flow is not rigidly confined, as it is in a II-2-2 I I I I I I I I I I I I I I I I I concrete channel. It may be influenced by changes caused by growth of macrophytes and terrestrial plants near the banks of the stream or by the accumulaton of obstructions such as litter and debris. Log-log plots of field data permit the determination of the constants and exponents in each of the equations. The constants and exponents will vary with the size of the river basin, and change over time due to natural erosion processes and man-made alterations such as dredging. Analysis of the available stream data has shown that more than one-third of the available data cannot be used in esti- mating the relationships, because the measurements had not been done at exactly the same location during each survey. These data were deleted from the data file. Equations were then derived for each stream reach based on the observed field measurements. The "no action" flows for each reach were then computed, based on the USGS results applied to the actual gauging station, and new stream widths and depths were calculated (see succeeding Figures II-2-1 through II-2-22). These dimensions are the best representa- tion that can be used for field conditions, and conform to the grid-section size used in the groundwater model. II-2-3 I I I I I I I I I I ! I I I I I I I FIG. II-2-1 PREDICTED STREAM CHARACTERISTICS ""' 8' "' AMITYVILLE CREEK O ~ ~7 ' ~ I 2.39 0.27 1750. llll. 0.06 2 1.93 0.11 1960. 421. 0.18 4 4.99 0.1~ 1900. 1641. 0.39 6 11.21 0.13 970. 1405. 0.69 0 0 ~ * I,~00' ~ ~E~c ~- ~ ~-~o -~-~o ~ ~E~C~- ~ I"'j '/70' · 2 .4 *.6 .8 GROUNDWATER PICKUP PER IOOO' (CFS) II-2-4 I I I I I I I I I I I I I I I I I I I FIG, II-2-2 PREDICTED STREAM CHARACTERISTICS 1 WOODS CREEK §. 0 2 4 J .e ID LZ L4 GROUNOV/ATk"R PICKUP PEN I000' (CFI) II-2-5 I i i I I I I I I i I I ! I I I I FIG, II-2-3 PREDICTED STREAM CHARACTERISTICS GREAT NECK CREEK 0.50 Z240. 292. I II-2-6 I I I I I I I ! I I I I I I I I I FIG, II-2-q PREDICTED STREAM CHARACTERISTICS I II-2-7 I I I I I' I I I I I I I I I I i ! FIG, II-2-5 PREDICTED STREAM CHARACTERISTICS NEGUNTATOGUE CREEK G~UN0~R PICKUP KR ~O' (CFS) II-2-8 I I I I ! I I I i I I I I I I I I ,I FIG, II-2-6 PREDICTED STREAiI CHARACTERISTICS SANTAPOGUE CREEK WEST BRANCH 8.. ~ ~t~i, 3~-~o' o §. 0 J .~ ,3 J .S · .T · GROUNDWATER PICKUP P~R I000' (CFS) II-2-9 I I I ! ! I I i I I I I I I il I I I I FIG, II-2-6 (CONT'D) PREDICTED STREAM CHARACTERISTICS SANTAPOGUE CREEK EAST BRANCH ..~ ...,, I'~ i ~ ~, e ] ° , GROUNDWATER PICKUP) PER 14000. (CFI) II-2-10 FIG, II-2-7 PREDICTED STREAM CHARACTERISTICS L,,,,, o ~ CARLL'S RIVER 1-~ ~ .43 / K~A ~-, ?.~K~ ~ ~.--~ ~ , T ?~Lvo. .7.?~ - ~~ ~,, 74 ~. - ?-e.) ~, ' / ~ ~" ~, ~' J"~ ,-,o~,.,o ~;, · -,. ~. '~ =':-~~1"' I I I I I I I 0 .,t 4 : '.J .8 I.O I.l k4 OROUNOWATEN PICIiUP PER IO(O! (CFI) I II-2-11 FIG, II'2'7 (CoNiC'D) PREDICTED STREAM CHARACTERISTICS I T---- ~ ------~,~~ I _,f ~ ,-~... ---'/ ~ ~1 ~. ~ gl, .,,, -I '- ~ ~/ ' , , I-4 I . , ih'. ' '1 0 .2 ~ .6 ~ I~ I,Z 1.4 I II-2-12 I I I I ! I I I i I I I I I I I i I FIG, II-2-8 PREDICTED STREAM CHARACTERISTICS II-2-13 I FIG. II 2 8 (CONT'D) PREDICTED STREAM CHARACTERISTICS I AVE. I I I J- 20 I I I AWLIYS I I I 4,00' il.S? .O6 0 .4 ~ J J 1.0 I.! GROUNDWATER PICKUP P[l~ I000' (Girl) 1.4 I.I 9 12.81 1.19 1500, 22847. 5.35 I I II-2-14 I I i I I I I I I I I I I I I I I FIG, II'2-9 PREDICTED STREAM CHARACTERISTICS O ~t ~4 .f, J LO I.s' GROUNDWATER PICKUP PER IOOO'(CFS) I II-2-15 I I ,I I I ! ! I I I I I I I I I I FIG, II-2-10 , PREDICTED STREAM CHARACTERISTICS 0 .2 ~ ~ .I 1.0 1.2 GROUNDWATER PICKUP PEN I000' (CPS) II-2-16 I I I I I I I I I I I ! I I I I I I FIG, IIL2'll ~ PREDICTED STREAM CHARACTERISTICS TRUES CREEK i 0.90 0.08 1280. 93, 0.04 2 3.17 0.14 900. 407. 0.16 3 3.86 0.25 1200. 1174. 0.53 4 4.28 0.34 2380. 3477. 1.01 8' ~ ~ ~00) O ~' 4 S lB 1.0 I,J 1.4 1.6 ~R~UND~A~TER PICKUP I~R I000' (¢F$) II-2-17 I I I I I I ! I I I I I I I I I I FIG, II-2-12 PREDICTED STREAM CHARACTERISTICS THOMPSONS CREEK I- ~ . .I ,"' .$ .4 .5 ,e .1' GROU#DWAT[Iq PICKUP I1~1t I000' II-2-18 I I I I I ! ! I I I I I I I I I I FIG, II-2-13 PREDICTED STREAM CHARACTERISTICS CASCADE LAKES ..,.K. LAKE /I Ii O-,11-11 0 .:) .4 .I .8 1.0 12 1.4. EROUNDWATER IqCKUI) PER I000' (CF$) I II-2-19 I I I I ! I ! I I I I I I I I I FIG, I1-2L14 ~ PREDICTED STREAM CHARACTERISTICS LAWRENCE CREEK 14 ~ KELLYS ~ND G -14- I }10~ -.S -.4' -.Z 0 2 d, .4 GROUN,W~TIrR PICKUP*PER I000' (CFS) ' m II-2-20 I I I I I I ! I I I I I I I I I ! I FIG, II-2-15 I PREDICTED STREAM CHARACTERISTICS 0 2 4 6 8 1.0 L2 1.4 GROUNDWATER PICKUP PER I000' (CFS) II-2-21 I ! I I ~ 8 - J! 1.30 0.13 1.76 0.21 7.63 0.17 0.79 0.00 6.52 0.51 9.57 0.61 I ]4 LENGTH VOLUME OUTFLOW 750. 122. 0.05 1290. 485. 0.20 2660. 3406. 1.18 1240. 0. 1.68 1110. 3662. 1.60 970. 5516. 3.91 720. 4191. 3.82 1000. 6199. 4.35 i 0 .Z 4 .% .8 LO I,Z GROUNDWATER PICKUP PER ~000' |CFI} m II-2-22 I I I ! I I ! I I I I I I I I I I FIG, II-2-16 (CoNY'D) PREDICTED STREAM CHARACTERISTICS PENATAQUIT CREEK WEST BRANCH ' GIIOUNDWATE~N PICKUP PEN IQO0' (CFI) m II-2-23 I I I I I I ! I I I I I I I I I I FIG, II'2-17 PREDICTED STREAM CHARACTERISTICS AWIXA CREEK 0 ,~ ti J .I 1,0 I.~ 1,4 GROUNDWATER PICKUP I~N I000' ((:Fi) ~ I II-2-24 I FIG i II-2-18 PREDICTED STREAM CHARACTERISTICS I' o~' 0ROWOC CREEK WEST I ~ -'COIi )~CK ! I I · II-IN g Il?l '.14 ,~'11 REACH WID~I~ DEPTH } ~EAC,I.I I0 i ~.3o 0.20 2 2.97 0.29 1"2'001 3 3.28 0.35 5 lO.lO 0.35 7 5.28 0,79 8 9.70 0.39 9 16.51 0.48 0 .2 .4 .6 .I I~) GNOUNOWATEI~ PICKIJ~ KR 1000' '1 II-2-25 ENGTH 2180. 2330. 1020. 1130. 1230. 1170. 1960. 1150. 2070. VOLUKB 1453. 1979. 1168. 3066. 4351. 12906. 8161. 4368. 16478. OUTFLOW 0.29 0.74 0.98 1.23 2.14 2.90 3.50 3.88 4.58 I I I I I I ! I I I I I I il I I I FIG, II-2-19 PREDICTED STREAM CHARACTERISTICS OROWOC CREEK EAST SOUTHERN ,,_, .,,., J o ~.~o ~ ~AC~ ~ ~-~ .~4 1-25 ~ ~A~ ~ I1~O~ ,,-, ~ ~_-,,-, 0 .2 .4 .6 .8 1.0 1,2 GROUNDWATER PICKUP PER lOGO* (Clr$) II-2-26 I I I I I I I ! I I I I I I I I I il :IGi II-2'20 PREDICTED STREAM CHARACTERISTICS : ,.. o.,, .o. ... ~.,o CREEK ~,o-, ~..~-, J ~-, ~ -,o-,j ] ~.~ ~ND~TER ~CKUP PE~ ~' (C~) m II-2-27 I I I I I I I I I I I I I I I I FIG, II-2-21 PREDICTED STREAM CHARACTERISTICS WEST BI'OK 0 ~ j .~,17~)' o o..,,.,, TFLOW 0 ' ~' 4 ~ · I0 I.s' I ~U#OWATElt CKUP ~11 IO00'(CFI) I II-2-28 I I 'i I I I I I I I I I I I I I I FI6. II-2-22 PREDICTED STREAM CHARACTERISTICS CONNETQUOT RIVER 0 g.~ UPPER SECTION .66 ---4 -~a-4 ~ ~ ~, ~-' .25 ~ ~ u g~ 6~ IzJo' I Lea ~° J 0 1.0 2.0 3.0 GROUNDWATER PICKUP PER IO00'(CFS) II-2-29 I I I I i I I ! I I ! I I I I I I I FIG, II'2'22 (CONT'D)' PREDICTED STREAM CHARACTERISTICS CONNETQUOT RIVER o LOWER SECTION o.- ° '~ 4.78 o .s6 I~:A"'H" / Jd~J~ 0 ~AClt WIDTH DEPTH LENGTH VOL U .~E OUTFLOW 0 1.0 20 $~ 6ROUNDWATER PICKUP PER I000' (CFS) 11-2-30 I I I I ! I I ! I I I i I I I I I I I 2.2 Lake and Pond Changes The steady-state geometry of each lake and pond studied in the project, together with the new predicted geometry, is shown in Table II-2-11 The initial features were developed in Milestone I by use of a planimeter on the water body contours. The predicted geometry was developed by subtracting the area lost due to the drop in the water table. Also included is residence time, which in all instances increases. This may cause additonal eutrophication to occur. However, the follow- ing conclusions were drawn from the lake and pond data pre- sented in Milestone I. Eutrophication of the lakes under study is a function of light, temperature, flow and phosphorus. The most important element controlling phytoplankton growth in the lakes is phos- phorus. While increases in the residence times may exacerbate the problem, there is no evidence to show that physical changes of this nature will necessarily cause algal blooms. 2.3 Water Quality The results of the steady-state and no-action water quality for each stream are presented in Chapter III. Only small changes can be observed, .both at the downstream stations and at intermediate points. This is due to the assumption used in predicting the change in groundwater with sewering and the degree to which improvements will occur. The groundwater data collected in Milestone I showed tremendous variability between sampling areas and at the same site. Estimating specific II-2-3 1 TABLE II-2-1 LAKE CHARACTERISTICS Stage Discharge ~urface Ar~a Perimeter Volume Residence Name (ft. above MSL) (CFS) (ft.2 x 10~) (ft. x 100) (ft.3 x 105) Time (hrs.) Avon Lake (SS) 6.11 2.75 14.719 22.27 9.91 100 Avon Lake ~NA) 4.93 0.54 13.045 20.13 8.24 409 Woods Lake (SS) 0.26 1.26 4.908 12.63 1.08 24 Woods Lake (NA) 0.08 0.40 3.983 11.35 .97 67 Great Neck Lake (SS) 2.83 2.40 7.839 12.58 . 1.76 20 Great Neck Lake (NA) 2.74 1.51 7.742 12.49 1.68 31 Elda Lake (SS) 22.35 5.53 21.110 20.89 14.52 73 Elda Lake (NA) 21.94 3.61 20.862 20.82 14.10 109 Geiger Lake (SS) 45.08 0.44 7.266 13.45 0.70 44 Geiger Lake (NA) 45.05 0.29 7.138 13.44 0.68 66 Belmont Lake (SS) 32.82 4.42 113.396 62.17 30.92 195 Belmont Lake (NA) 32.38 2.88 107.241 60.23 26.22 253 Southards Pond (SS) 13.98 17.87 109.271 41.'99 23.37 36 Southards Pond (NA) 13.75 11.65 107.680 41.87 20.90 50 Argyle Lake (SS) 6.22 23.39 95.785 43.86 19.13 23 Argyle Lake (NA) 5.81 15.24 93.259 42.48 15.46 28 Guggenheim Lakes (SS) 36.0 3.18 88.965 73.50 28.29 247 Guggenheim Lakes (NA) 35.93 1.82 88.241 73.27 27.28 425 Scott Lake (SS) 20.76 6.35 18.594 48.00 6.04 26 Scott Lake (NA) 20.69 3.63 18.401 47.51 5.92 45 Cobb Lake (SS) 14.56 7.30 6.748 12.70 2.57 10 Cobb Lake' (NA) 13.93 4.18 6.185 11.91 2.15 14 Hawleys Lake (SS) 4.77 9.50 22.085 21.77 6.67 20 Hawleys Lake (NA) 4.70 5.44 21.937 21.79 6.51 33 SS: Steady state NA: No action TABLE II-2-1 (cont'd) Stage Discharge Surface Area Perimeter Volume Residence Name (ft. above MSL) (CFS) (ft.2 x 104) (ft. x 100) (ft.~ x 105) Time (hrs.) Lake Capri (SS) 4.50 2.60 35.246 26.00 9.18 98 Lake Capr~ (NA) 4.48 1.29 35.134 25.98 9.11 196 Nosreka Lake (SS) 11.16 0.00 7.374 13126 2.05 83 Nosreka Lake (NA) 10.51 0.00 6.908 12.98 1.60 99 Lagoon Lake (SS) 8.94 1.14 6.086 17.98 1.72 42 Lagoon Lake (NA) 8.87 0.74 6.052 17.97 1.68 63 Upper Cascade Lake (SS) 9.08 1.74 19.737 17.70 9.91 158 Upper Cascade Lake (NA) 8.94 1.19 19.577 17.68 9.64 224 Lower Cascade Lake (SS) 5.93 2.20 18.707 18.36 2.84 36 Lower Cascade Lake (NA) 5.46 1.49 16.975 17.42 2.03 38 O-Co-Nee Lake (SS) 10.49 1.36 11.305 12.96 5.74 117 O-Co-Nee Lake (NA) 10.18 .51 10.930 12.87 5.46 299 Lawrence Lake (SS) 6.50 1.40 28.109 23.63 6.15 122 Lawrence Lake (NA) 6.19 .52 26.321 23.23 5.36 286 Montfort Lake (SS) ' 0.97 1.40 8.329 13.70 1.82 36 Montfort Lake (NA) 0.96 1.27 8.315 13.69 1.82 40 Orowoc Lake (SS) 2.62 5.80 20.389 18.06 8.07 39 Orowoc Lake (NA) 2.60 4.56 20.299 18.02 8.03 49 Upper Pardees Pond (SS) 8.10 3.52 16.057 23.15 8.98 71 Upper. Pardees Pond (NA) 8.10 2.60 16.057 23.15 8.98 96 Lower Pardees Pond (SS) 5.58 3.90 20.026 21.29 5.17 37 Lower Pardees Pond (NA) 5.58 2.88 20.026 21.29 5.17 50 Ducks Lake (SS) 10.36 5.69 6.390 9.64 2.00 I0 Ducks Lake (NA) 10.27 4.33 6.265 9.30 1.66 !1 SS: Steady state NA: No action m m m mm m mm m mm m m m m m m m mm mm m m TABLE II-2-1 (cont'~) Stage Discharge Surface Ar~a Perimeter Volume Residence Name (ft. above MSL) (CFS) (ft.2 x 10~) (ft. x 100) (ft.3 x 105) Time (hrs.) Knapps Lake (SS) 10.03 6.40 80.259 56.86 20.26 88 Knapps'Lake (NA) 9.99 4.87 79.810 56.44 19.95 114 Upper Winganhauppauge Lake (SS) 4.94 6.40 45.032 38.69 9.68 42 Upper Winganhauppauge Lake (NA) 4.86 4.87 44.950 38.51 9.35 53 Upper West Brook Lake (SS) 5.17 3.63 17.486 29.34' 2.49 19 Upper West Brook Lake (NA) 5.16 3.21 21.120 30.00 2.48 21 Lower West Brook Lake (SS) 5.96 3.90 48.692 28.96 13.91 99 Lower West Brogk Lake (NA) 5.95 3.45 49.079 29.00 13.88 112 Hatchery Pond (SS) 14.20 29.38 58.921 63.67 14.00 13 Hatchery Pond (NA) 14.19 27.44 58.764 63.63 13.92 14 Main Pond (SS) 6.15 36.31 77.680 55.91 20.65 16 Main Pond (NA) 4.94 33.91 65.754 54.76 19.80 17 SST Steady state NA= No action I I I I ! ! I ! I I I I I I I I ! changes would lead to using values with plus or minus limits of at least 100 percent. However, it was concluded that after sewering, the groundwater quality would not degrade any further than its present quality. Therefore, the impact value of groundwater quality used in the stream models was the same value presented in Milestone I. Some small changes in quality will result from the shortening of a stream and increased de- tention time (elevated phosphorus and biomass). It should also be noted that the same distribution of flow to upstream sta- tions was used in the steady-state and no-action flows. II-2-35 I I I ! I I I ! I I I I I I I I I I REFERENCES FOR SECTION 2 1) 2) 3) Leopold, L. B., and T. Maddock, Jr., "The Hydraulic Geometry of Stream Channels and Some Physiographic Impli- cations,'' U.S. Geological Survey Professional Paper 252, USGS, Washington, D.C., 1953. O'Connor, D. J., "The Effect of Stream Flow on Waste Assimilation Capacity," presented at 17th Purdue Indus- trial Waste Conference, Lafayette, Indiana, May, 1962. Chang, H. H., "Geometry of Gravel Streams," the Hydraulic Division, ASCE, Vol. 106, No. 1456, September, 1980. Journal of HY9, pp. 1443- I I I I i I I ! I I I I I I I I I I SECTION 3 - GREAT SOUTH BAY MODEL 3.0 Discussion Calibration of the Great South Bay salinity model to measured September, 1976 conditions, successful verification against September, 1978 conditions, and the calculation of the "no-action" alternative impacts for post-sewering conditions in Nassau and Suffolk Counties has been completed. In order to calculate the no-action impact, the following two model runs were made: 1) Present "steady state" 1968-1975 average streamflows and underflows, as supplied from the USGS regional and sub- regional models. 2) The predicted "no action" streamflows and underflows representing the full long-term stressing of Nassau and Suffolk County sewering, as supplied from the USGS regional and sub- regional models. Table II-3-1 presents the stream-by-stream flows and gross zonal underflows for the entire south shore bay system as rep- resented in the bay model. The streamflows shown include both baseflow calculated by the USGS and average annual runoff for the period 1968-1975. The last column in Table 1 shows the percentage decrease in stream baseflows and underflows attrib- utable to the sewering stresses. These flows differ somewhat from those shown in Section 2, since they include the flow to II-3-1 I I i I I ! I ! I I I I I I I I I I TABLE II-3-1 COMPARISON OF STEADY STATE "PRESENT" AND "NO-ACTION" FRESHWATER INFLOWS TO BAY MODEL (All Fl¢¥~s in CSF) PRESENT AVERAGE N 0- ACT I ON %Change lg6R-lg/5 (decrease) USGS STEADY STATE STEADY STATE NO-ACTION NO ACTION ~ALOG OTAL STREAM FLOWS USGS MODEL TOTAL STREAM FLOWS USGS MODEL MODEL TRIBUTARY FOF[ FULL STRE~LM UNDERFLOW FOR FULL STREAM UNDERFLOW STREA~ UNDER ~¥ ZONE NAME LENGTH {USED IN MODEL ) TO BAY LENGTN(USED IN )~)DEL) TO BAY FLOWS FLOW ~ 7.7 Hempstead -~ Mill River (E+W)SouthPines BrOOkpond 5.8 25% ,Bay ~z Parsonage Creek IR.19'l 7.75'8 45%36% Middle o Milburn Creek 46% Bay M Cast Meadow Brook 13.6 7.4 I ~ Cedar Swamp Creek 9.0 4.3 52% Cast Bay w A Newbridge Creek 1.6 42.3 0.8 32.3 50% 24% i South Seamans Creek 6.4 2.3 64% ;Oyster Bay Seaford Creek 5.8 2.7 53% y Massapequa River 13.0 6.0 54% , J k Amityville Creek 3.9 1.6 59% Woods Creek 4.2 3, 1 25% Unnam~ (A~J%) 1.7 1.5 14% Great Neck Creek 3.9 2.6 33% Western Strongs Creek 3.7 2.6 30% Great Unnamed (BBB) 1.3 1.O 21% South Neguntatogue Creek 4.9 2.5 49% Bay Santapogue Creek 9.6 5.3 45% Unnam~ {CCC) 3.7 3.1 32% Carlls River 27.9 92.0 21.1 24% Sampawams Creek ll.7 8.5 27% Willets Creek 2.6 1.6 85.3 40% Trues Creek 3.3 2.7 ] 19% lhcmsons Creek 2.4 2.1 13% ~ Cascade Lakes 4.2 3.6 14% -~ Lawrence Creek 1.6 1.5 8% 7% z B Watchogue Creek 1.6 1.3 17% Central o Fenataquit Creek 7.2 5.3 26% Great M Awixa Creek 2.2 1.9 I4% South ~ Oro~oc Creek G.S 5.6 14% Bay ~ Pardees Pond 4.1 3.5 14% ~ Champl in Creek 8.4 6.5 23% m West Brook 3.9 3.6 7% ~ ~nnetquot River 37.2 36.8 ~ Rattlesnake Brook 9.2 9.2 0% Unnamed (EEE) 3.5 3.5 0% ! Green Creek 7.4 7.4 , 0% Sub Totals 184.7 151.5 Brown Creek 8.3 8.3 Tuthills Creek 6.4 6.4 Eastern Patchogue River El.I 21,1 Great Swan River 13.0 13.0 5.5 South Mud Creek 5.5 1.1 Bgy .J Hedges Creek 1.) Motts Creek 2.0 2.0 ': Beave~am Creek 2.0 2.0 z Camans River 44.1 44.1 o 72.0 71.9 0% 0% ~ Pattersquash Creek 1.0 1.O I m Forge River 9.6 9.6 ~ Terrell River 2.5 2.5 ~ C Little Seatuck Creek 4,7 4.7 I~oriches Seatuck Creek 6.0 6.0 Bay East River 2.8 2.8 Speonk River 2.5 Beaverdam Creek 2, S 2.4 Aspatuck Creek 2.4 , Quantuck Creek 2-3 2.3 ~ , Sub Totals l~ GP~ARD TOTALS 425.4 ~ 206.3 343.1 ~ 1Bg.50 19% ~ 8% 631.7 532.6 16% II-3-2 I I I I I I I ! I I I I I I I I i ! the mouth of the stream and overland runoff. The remaining inputs to the bay model (i.e., meteorological conditions, existing treatment plant discharge flows and ocean inlet bound- ary conditions) were kept identical in both model runs, such that the only differences were the streamflows and underflows. Figures II-3-1a and II-3-1b present the calculated steady- state results of the Changes in bay salinities between steady- state conditions and the no-action condition. Salinities in- crease by a maximum of about one part per thousand in the open part of the bay close to the mouths of the Carll's and Sampawams Creeks. From here, the increase drops off rapidly to one-half part per thousand at the Nassau-Suffolk border on the west, and at the Connetquot River on the east. It is observed that sa- linity increases of greater than one part per thousand occur up in the mouths of Amityville, Great Neck, Strong's, Negun- tatogue, Santapogue, Carll's, Sampawams, Willets, Trues, Cas- cade Lakes, Penataquit, Orowoc, and Champlin Creeks. The maximum observed increase was 1.95 parts per thousand up in the marine portion of the Carll's River. These model calculations indicate, as was also shown dur- ing the previous 208 modeling study (Tetra Tech, 1977), that bay salinity levels west'of the Carll's River and especially in the Nassau County bay areas are largely insensitive to major long-term changes in fresh water inflows. This is due to the dominating ocean flushing forces through East Rockaway, Jones and Fire Island Inlets. On the other hand, Great South Bay east of Fire Island Inlet is subject to weak tidal flushing II-3-3 I I ! I I I I ! ! I I I I I I I ! I i and is therefore much more sensitive to long-term inflow variations. The fact that salinities increase by roughly one- half part per thousand throughout eastern Great South Bay, even though very little decrease in fresh water inflows east of the Carll's River-occurs under no-action, is attributed to this phenomenon. II-3-4 mm m m mm m ,mm mm mm m m m mm m m m m m mm m FIGlJILE II-3-1(a) Calculated Increase in Bay Salinities (PPT) due to the No-Action Sewering Stresses I I I I I ~ T~TIC I I I ,o2 ATLANT/C OCEAN II-3-6 I I I I I I I ! I I I I I I I I I ! I REFERENCES FOR SECTION 3 Tetra Tech, 1977. Water Quality Modeling - Hempstead, Middle, East, South Oyster and Great South Bay, Long Island, New York. Prepared for Nassau-S~ffolk Regional Planning Board 208 Study. Tetra Tech, 1981. Flow Augmentation Needs Study - Circulation and Dispersion Modeling of the Great South Bay and Contiguous Regions. Under preparation for Suffolk County Department of Health Services. I I I I I I I ! I I I I I I I I I I SECTION 4 - STREAMBED EXFILTRATION 4.0 Discussion Preliminary data from the U.S. Geological Survey's modeling of the Suffoik FANS area shows that, based on an annual average, baseflow to streams can be expected to de- crease by approximately 34 cfs (cubic feet per second) as a result of reduced recharge due to sewering. This decrease in baseflow is a total for all the district's 22 streams and tributaries. In order to return the flow in the streams to their pre- sewering levels, water in excess of the 34 cfs must be added to the streams, because some of this water will move out of the stream channel to become bank storage. More specifically, after the full effects of sewering have been felt, a new water- table gradient will be established to reflect the reduced stream flow. This information was presented in previous sec- tions. Should augmentation of stream(s) take place, the flow and level of the stream will increase, but the new stream level will not be in equilibrium with the water-table gradient occur- ring adjacent to the stream. Water from the stream will tend to flow out of the channel into the unsaturated sediments above the water table (an increase in bank storage) until a new steady- state water table has been established. Determining the amount of water needed to satisfy this bank storage is, therefore, important for the mitigation design. II-4-1 '1 I I I I I I I I I I I I I I I I I I I During December 1979, the U.S. Geological Survey conducted recharge field tests along Fosters Brook in the Franklin Square area of Nassau County. Fosters Brook is a dry streambed that contains water only after a rainfall, and the groundwater table in the testing area is usually 6 to 8 feet below the streambed. Water was added to the dry streambed at an initial rate of 1 cfs (approximately 450 gallons/minute) for a period of 12 days. After this time, the volume of water added to the stream- bed was increased to 1.63 cfs and maintained at that level for 8 days. Finally, the volume of water was reduced to 0.53 cfs and maintained until the end of the test--an additional 6 days. During the testing periods, the length of the stream (furthest point downstream of measurable flow) was measured, along with stream flow and groundwater table elevations. Stream flows were measured at points 300, 678, 1159 and 1929 feet down- stream of the point where the augmented water was added. The field testing at Fosters Brook showed that at the end of the 1 cfs augmentation run, the streambed was losing water at a rate of 7.44 x 10-4 cfs/ft. (per foot of stream length), and at the end of the 1.63 cfs augmentation run, the streambed was losing water at a rate of 7.70 x 10-4 cfs/ft. Utilizing this data for mitigation design to streams in Suffolk County presents major problems. Although the south shores of Nassau and Suffolk Counties are in a general way hydrogeologically similar, they are drastically different in detail. The USGS preliminary no-action results show that all II-4-2 I I I I I I I ! I I I I I I I I I streams in Suffolk's Southwest Sewer District will continue to flow (on an average annual basis), although the headwaters of some will be somewhat reduced in length, which indicates that the unsaturated zone will remain generally close to the streambed in most ar~as. At Fosters Brook, however, on the average, the water table is 6 to 8 feet below the streambed. All else being equal, this lower water level relative to the streambed would result in significantly greater water losses during augmentation than where the water is closer to the streambed, as will be the case in Suffolk. This is due to the unsaturated zone existing beneath the streambed (at Fosters Brook) that must be filled with water before a new steady- state condition can be established. A second problem relates to differences in permeability between Fosters Brook and Suffolk County streams. These rates may even vary from stream to stream which will affect any ex- trapolation of Foster Brook data. Another problem deals with a factor of potential clogging for the existing streambed. This was observed during the test- ing at Fosters Brook, where it was shown that macrophytes will appear in the streambed and cause clogging. This phenom- enon would decrease the amount of exfiltration and tend to make the observed rate at Fosters Brook more conservative. Since these difficulties create a potential for a great variability in flows to be used for mitigation design, a more appropriate method would be to analyze the specific areas II-4-3 I I I I I I I ! I I I I I I I I I I I needing mitigation, or a case-by-case application defining such parameters (depth to water, hydraulic gradient, perme- ability, cross section area) to estimate the leakage. This will be attempted for Milestone III decisions. At this time, a~ although these difficulties persist, the Foster Brook data is the only applicable information available. Therefore, for future design, an exfiltration rate of 7.44 x 10-4 cfs will be used for each foot of stream re- quiring augmentation, and a maximum discharge rate at any one point in the stream of 1 cfs will be used. Should discharges lower than 1 cfs (450 gpm) be required, the exfiltration rate will be even more conservative. II-4-4 I I I ! I I I I I I I I I I I I I I I CHAPTER II:I. :ENVIRONMENTAL RESULTS Section 1 - Environmental Results 1.0 Discussion Section 2 - Environalental Impacts 2.0 Discussion Section 3 - Discussion of Results 1.0 Introduction 2.0 Ecology 3.0 Aesthetics 4.0 Recreation 5.0 Residential Properties Values 6.0 Water Quality Page No. III-l-1 III-2-1 III-3-1 III-3-2 III-3-6 III-3-11 III-3-t7 III-3-20 I I I I I i I I I I I I I i I I I SECTION 1 - ENVIRONMENTAL RESULTS 1.0 Discussion The material presented in this section represents the compilation of the no-action, environmental quality of life (EQOLI) results. Factors used to determine the EQOLI are: ecology (terrestrial and aquatic); aesthetic (scenic areas); recreation (parks); socio-economic (property value); and water quality. In Milestone I these factors were compiled for all 22 streams, and they were summed in two ways: the first was just a straight addition of the factors; the second saw the factors added after each one was multiplied by a specific weighting factor determined through a Delphi Group. The analy- sis for Milestone II was performed in a similar fashion using information supplied by the USGS (streamflow, water-table change) and Tetra Tech (water quality, stream width and depth, biomass, lake geometry). Table III-l-1 presents the summary of the factors for each stream and the two summations. This represents the environ- mental value of each stream when the full groundwater impact of sewering is realized. The numbers, standing alone, offer little information about the nature and extent of the impact. This is presented in Section 2, Environmental Impacts. III-l-1 TABLE III-l-1 SUMMARY OF ENVIRONMENTAL FACTORS PROP~RTX' WATER CEV EQLI Factor ECOLOGY AESTHETICS P~ECREATION VALUE QUALITY STREAM Weight (Delphi) 0.264 0.168 0.156 0.143 0.269 ~ Ri ~W.R. 1. AMITYVILLE CREEK 0,97 2.75 5.03 3.13 7.58 19.46 3.989 2. WOODS CREEK 1.28 1.51 0.58 1.06 7.63 12.06 2.886 3. GREAT NECK CREEK 2.24 4.07 1.30 0.87 7.94 16.42 3.738 4. STRONGS CREEK 0.51 2.44 0.00 2.54 7.65 13.14 2.966 5. NEGUNATATOGUE CREEK 1.43 3.64 3.11 1.50 6.69 16.37 3.488 6. SANTAPOGUE CREEK 5.71 4.49 0.77 4.18 7.63 22.78 5.032 7. CARLLS RIVER 7.57 6.69 9.67 9.11 8.06 41.10 8.102 8. SAMPAWAMS CREEK 7.57 5.69 5.42 9.85 8.02 36.55 7.366 9. SKOOKWAMS CREEK 0.51 7.07 0.00 1.39 6.70 15.67 3.323 10. WILLETS CREEK 3.57 4.13 1.83 2.64 7.78 19.95 4.392 11. TRUES CREEK 4.08 4.36 1.42 2.77 7.94 20.57 4.563 12. THOMPSONS CREEK 0.87 3.67 0.00 1~49 7.49 13.52 3.074 13. CASCADE LAKES 0.87 9.35 5.24 3.00 8.24 26.70 5.263 14. LAWRENCE CREEK 2.04 5.28 3.06 1.78 8.06 20.22 4.326 15. WATCHOGUE CREEK 0.31 1.22 0.00 0,66 6.84 9.03 2.221 16. PENATAQUIT CREEK 5.99 6.04 0.00 1.67 7.73 21.43 4.914 17. AWIXA CREEK 5.10 4.49 1.35 1.58 7.73 20.25 4.617 18. OROWOC CREEK - WEST BRANCH 6.30 5.95 2.41 1.80 7.94 24.40 5.432 19. OROWOC CREEK - EAST BRANCH 7.59 6.71 2.79 1.19 7.82 26.10 5.840 20. CHAMPLIN C~EEK 5.28 6.64 5.58 5.67 8.00 31.17 6.343 21. WEST BROOK 5.75 7.53 1.67 0.00 8.39 23.34 5.300 22. CONNETQUOT RIVER 10.00 7.91 6.01 0.00 8.50 32.42 7.193 CEV = Composite Environmental Value EQLI = Environmental Quality of Life Index I I i i ! i I ! I ! I I I I I I I I i SECTION 2 - ENVIRONMENTAL IMPACTS 2.0 Discussion Table III-2-1 presents each stream, its EQOLI the present case (Milestone I), the no-action case factor for (Milestone II), the difference between them (impact) and the ranking of that impact from one to twenty-two. This is shown for both weighted and unweighted conditions. As was the case in Mile- stone I, little change in ranking is observed when comparing each method. The table does show that streams west of the Carll's River will receive the greatest impact, with Amityville Creek, the most westerly stream, changing the most. Table III-2-2, the impact by stream and by factor (~), was constructed to allow a closer look at which factor might be causing a specific impact on a stream. Observations are: ® Water quality changes are negligible. ® Property value changes are small to negligible. impacts only appear to be affecting five · Recreation streams. · Aesthetics seem to be the most sensitive to change. This is due to the importance that parameters such as exposed bank width and width of stream have on the rating. These parameters are affected by the decreasing stream widths, and shortening of the stream will' automatically reduce the rating. · Changes in ecological ratings are caused solely by changes in aquatic ecology. III-2-1 TABLE III-2-1 PREDICTED CHANGES IN STREAM ENVIRONMENTAL VALUES Factor Composite Environmental Value Environmental ~,uality of Life Index STREAM Weight (Delphi) PC NA A Rank PC NA A Rank 1. AMITYVILUE CREEK 22.34 19.46 2.88 1 4.569 3.989 0.580 1 2. WOODS CREEK 14.18 12.06 2.12 2 3.247 2.886 0.361 3 3. GREAT NECK CREEK 17.84 16.42 1.42 6 3.922 3.738 0.184 8-9 4. STRONGS CREEK 13.58 13.14 0.44 12 3.038 2.966 0.072 12 5. NEGUNTATOGUE CREEK 18.17 16.37 1.80 5 3.791 3.488 0.303 5 6. SANTAPOGUE CREEK 24.62 22.78 1.84 4 5.344 5.032 0.312 4 7. CARLLS RIVER 43.03 41.10 1.93 3 8.476 8.102 0.374 2 8. SAMPAWAMS CREEK 37.56 36.55 1.01 9 7. 550 7. 366 0. 184 8-9 9. SKOOKWAMS CREEK 15.67 15.67 -0- 21-22 3.323 3.323 -0- 21-22 10. WILLETS CREEK 21.17 19.95 1.22 8 4.644 4.392 0.252 7 11. TRUES CREEK 20.93 20.57 0.36 13 4.622 4.563 0.059 13 12. THOMPSON CREEK 13.52 13.52 -0- 21-22 3.074 3.074 -0- 21-22 13. CASCADE LAKES 27.38 26.70 0.68 10 5.380 5.263 0.117 10 14. LAWRENCE CREEK 21.61 20.22 1.39 7 4.589 4.326 0.263 6 15. WATCHOGUE CREEK 9.56 9.03 0.53 11 2.310 2.221 0.089 11 16. PENATAQUIT CREEK 21.69 21.43 0.26 15-16 4.960 4.914 0.046 15 17. AWIXA CREEK 20.27 20.25 0.02 20 4.620 4.617 0.003 20 18. OROWOC CREEK - WEST BRANCH 24.69 24.40 0.29 14 5.485 5.432 0.053 14 19. OROWOC CREEK - EAST BP~ANCH 26.17 26.10 0.07 18-19 5.852 5.840 0.012 18-19 20. CHAMPLIN CREEK 31.37 31.17 0.20 17 6.378 6.343 0.035 17 21. WEST BROOK 23.41 23.34 0.07 18-19 5.312 5.300 0.012 18-19 22. CONNETQUOT RIVER 32.68 32.42 0.26 15-16 7.236 7.193 0.043 16 PC = Present Conditions NA = No Action Conditions A = Predicted Change Rank = Rank of Predicted Change m m mm mmm mm mm m m m m m m m mm m m TABLE III-2-2 PREDICTED CHANGES IN ENVIRONMENTAL FACTORS ECOLOGY AESTHETICS RECP~EAT I ON SOCIO-ECONOMICS WATER QUALITY STP~EAM ~ Rank A Rank A Rank A Rank A Rank 1. AMITYVILLE CREEK 1.02 1 1.72 1 0.08 6 0.06 4 I 2. WOODS CHEEK 0.10 8 1.67 2 0.33 4-5 0.02 6~10 I 3. GREAT NECK CREEK 0.31 5 0.60 9-10 0.01 14-15 -0- 15-22 I 4. STRONGS CREEK -0- 13-22 0.43 12 -0- 16-22 0.02 6.10 I 5. NEGUNTATOGUE CREEK 0.06 9 1.03 3 0.69 2 0.02 6-10 I 6. SANTAPOGUE CHEEK 0.14 7 0.91 5 0.72 1 0.07 2-3 I 7. CARLLS RIVER 0.58 2 0.95 4 0.33 4~5 0.07 2.3 I 8 . SAMPAWAM$ CREEK 0 . 20 6 0 . 60 9-10 0 . 06 8 0 . 15 1 I 9. S KOOKWAMS CREEK -0- 13-22 -0- 21-22 -0i 16-22 -0- 15-22 I 10. WILLETS CREEK 0.51 3 0.62 8 0.05 9 0.04 5 -0- ~ 11. TRUES CREEK -0- 13-22 0.28 13 0.07 7 0.01 11-14 ~ 12. THOMPSONS CREEK -0- 13-22 -0- 21~22 -0- 16-22 -0- 1~-22 ~ O 13. CASCADE LAES -0- 13-22 0.65 6 0.03 10 0.02 6-10 ~ 14. LAWRENCE CREEK 0.36 4 0.63 7 0.38 3 0.02 6-10 I 15. WATCHOGUE CREEK -0- 13-22 0.53 11 -0- 16-22 -0- 15-22 I 16. PENATAQUIT 0.02 11-12 0.23 15 -0- 16-22 0.01 11-14 I 17. AWIXA CREEK -0- 13-22 0.02 20 -0- 16-22 -0- 15-22 I 18. OROWOC CHEEK - WEST BRANCH 0.05 10 0.18 16 0.02 11-13 0.01 11-14 I 19. OROWOC CREEK - EAST BRANCH -0m 13-22 0.07 18 -0- 16-22 -0- 15-22 I 20. CHAMPLIN CHEEK 0.02 11-12 0.16 17 0.01 14-15 0.01 11-14 I 21. WEST BROOK -0- 13-22 0.05 19 0.02 11-13 -0- 15-22 I 22. CONNETQUOT RIVER -0- 13-22 0.24 14 0.02 11-13 -0- 15-22 ~ A = Predicted Change Rank = Rank of Predicted Change I I I I I I I ! I I I i I I I I i / ! · Amityville Creek, receiving the greatest impact, is greatly impacted by five factors. Its flow is predicted to decrease by 70 percent, and it may shorten by 3/4 mile. Reviewing the specifics of the changes, to isolate seg- ments of the streams with greater impacts than others, produced only the fact that lakes play an important role in a stream's rating. This is because lakes supply and support much of the stream's aquatic ecology (fish, phytoplankton and macrophytes), provide most all of the recreational value of a stream and con- tribute heavily towards the aesthetic importance of a stream. III-2-4 I I i I I '1 I II I I / i I i I I I I SECTION 3 - DISCUSSION OF RESULTS 1.0 Introduction The purpose of this section is to describe projected changes in stream ratings resulting from the post-sewering conditions if no mitigation measures are implemented ("No Action Alternative"). Projected changes will be described by five environmental parameters including (1) ecology, (2) aes- thetics, (3) recreation, (4) socio-economics (residential property values) and (5) water quality. These parameters were used in Milestone I of this study, to assess relative values of all 22 streams located within the study area. Five environmental models were developed utiliz- ing input data compiled during an extensive field sampling program. These five models have been employed in this phase of the study to project new ratings of the streams based on the five environmental parameters under "No Action" conditions. III-3-1 I I I I ! i t ! I I I I I I I I I i I 2.0 Ecology Quantitative and qualitative alterations of terrestrial and aquatic ecosystems of each of the 22 stream basins have been assessed. Based on qualitative changes relative to pre- sent conditions, new ratings have been calculated for both component ratings and for new composite ecological ratings. Ratings based on present conditions and future conditions as- suming no mitigating action, are presented in Table III-3-1. Figure III-3-1 relates the magnitude of the change in the normalized ecological ratings (impacts of "No Action" condi- tions) given in Table III-3-1, to each stream basin. This graph and table indicate that Amityville Creek, for reasons to be discussed below, far exceeds all other streams with respect to change in ecological rating. Of the 21 remaining stream basins, only 11 are expected to demonstrate any change in overall ecological quality. All other basins are expected to experience no impact to their natural environments resulting from lowering of the ground water table. Decreasing ground water levels will produce little ob- servable change in the terrestrial regimes of the individual stream basins. Those changes that are expected to Occur are relatively slight, and long-term in nature. Changes are ex- pected more frequently in the western portion of the study area where maximum drawdown will occur. Terrestrial eco- systems of the eastern portion of the project area, such as in the West Brook and Connetquot River basins, demonstrate ab- solutely no alterations. III-3-2 TABLE III-3-1 SUMMARY OF ECOLOGICAL RATINGS CHANGE IN RATING (IMPACT) 0 .0 0 0 0 0 0 0 C RIVER ,ETS CREEK !NCE CREEK NECK CREEK ;AMPAWAMS CREEK DGUE CREEK CREEK NEGUNTATOGUE CREEK )ROWOC CREEK-WEST CREEK CHAMPLIN CREEK STRONGS CREEK SKOOKWAMS CREEK TRUES CREEK THOMPSONS CREEK CASCADE LAKES WATCHOGUE CREEK AWXIA CREEK OROWOC CREEK-EAST WEST BROOK CONNETQUOT RIVER AMITYVILLE CREEK rtl 0 I- 0 rtl I I I I I I I I I I i I I I I I I I I I I I I I I I I I ,I I I I I I I I I Terrestrial impacted will over extended components of those stream basins which are go through subtle successional modifications periods of time. The most observable effects will occur more proximal to the stream itself where con- stituent flora and fauna of the terrestrial communities are highly dependent on water availability. Peripheral portions of communities such as the swamp forest, may give rise to more transitional forest types. In areas of extensive drawdown, small portions of mesic forest may be replaced with more up- land forest types. Deterioration in the aquatic components of the stream basins more obviously corresponds with decreases in composite ecological ratings. The most obvious deterioration which is observed in the Amityville Creek system is due to negative im- pacts on the biological communities (specifically, inver- tebrate and fish fauna) which now occur in Avon Lake. Drying of the stream bed for several thousand feet in its upper reaches will represent an additional and significant habitat loss to indigenous aquatic biota. The majority of the deterioration in other impacted stream systems within the study area, such as Carll's River and Willets and Lawrence'Creeks, will be felt mostly in lentic ecosystems, (ponds and lakes). This will be due to a decrease in dilution capacity for nutrients and contaminants and, in many cases, an increase in retention time of the water body. III-3-5 I I I I I I I ! I I I i I I I I I I Both the Woods Creeks The next group than the above Carll's River, 3.0 Aesthetics An as~sthetic model in Milestone I was developed based on consideration of 12 parameters. Evaluation of these para- meters under present (pre-sewering) conditions and analysis of stream aesthetics within the study area was performed in Mile- stone I to rank the streams according to their relative aesthetic attractiveness. The aesthetic parameters were re- evaluated and new stream aesthetics ratings computed, to re- flect the post-sewering conditions under the "No Action" al- ternative. Table III-3-2 shows the resulting values of the stream aesthetic ratings under present and no action conditions. The differential between these two ratings indicates the impact of the "No Action" alternative on the stream aesthetic values. The last column in Table III-3-2 ranks the stream according to the projected impacts, with rank "1" given to the most impact- ed stream and rank "22" assigned to the least impacted stream. Relative impacts of the "No Action" alternative on the stream aesthetic values are graphically depicted in Figure III-3-2. table and figure indicate that Amityville and are expected to be the most impacted streams. exhibiting somewhat milder projected impacts two streams, includes Neguntatogue Creek, and Santapogue Creek. Cascade Lakes and Lawrence, Willets, Sampawams, Great Neck, Watchogue and Strong's Creeks can be considered to be the next group in the order of the decreasing aesthetic impacts. The remaining 10 streams exhibit either small or no impacts. III-3-6 TABLE III-3-2 SUMMARY TABLE OF AESTHETIC RATING Amityville Creek woods Creek Great Neck Creek Strong's Creek Neguntatogue Creek Santapogue Creek Carll's River Sampawams Creek Skookwams Creek Willets Creek Trues Creek Thompson's Creek Cascade Lakes Lawrence Creek Watchogue Creek Penataquit Creek Awixa Creek Orowoc Creek - West Orowoc Creek - East Champlin Creek West Brook Connetquot River A~STHETIC NORMALIZED RATING RATING PC NA PC NA _A RANKING 3.76 2.99 4.47 2.75 1.72 1 3.18 2.43 3.18 1.51 1.67 2 3.85 3.58 4.67 4.07 0.60 9-10 3.04 2.85 2.87 2.44 0.43 12 3.85 3.39 4.67 3.64 1.03 3 4.18 3.77 5.40 4.49 0.91 5 5.19 4,76 7.64 6.69 0.95 4 4.58 4.31 6.29 5.69 0.60 9-10 4.93 4.93 7.07 7.07 -0- 21-22 3.89 3.61 4.75 4.13 0.62 8 3.84 3.71 4.64 4.36 0.28 13 3.40 3.40 3.67 3.67 -0- 21-22 6.25 5.96 10.00 9.35 0.65 6 4.41 4.13 5.91 5.28 0.63 7 2,54 2.30 1.75 1.22 0.53 11 4.57 4.47 6.27 6.04 0.23 15 3.78 3.77 4.51 4.49 0.02 20 4.51 4.43 6.13 5.95 0.18 16 4.80 4.77 6.78 6.71 0.07 18 4.81 4.74 6.80 6.64 0.16. 17 5.16 5.14 7.58 7.53 0.05 19 5.42 5.31 8.15 7.91 0.24 14 Notes: PC = Present Conditions NA = Future Conditions should no action be taken A = Predicted change in normalized rating Rank is based on impact due to No Action (=Impact) 8-E-III CHANGE IN RATING ( IMPACT) ~> .-- .-- .'- 0 0 0 0 AMITYVILLE CREEK 30DS CREEK UNTATOGUE CREEK ARLL'S RIVER u~ SANTAPOGUE CREEK o~ CADE LAKES '~ LAWRENCE CREEK WlLLETS CREEK · ~- SAMPAWAMS CREEK -~ o GREAT NECK CREEK ~ =- ;HOGUE CREEK r~ CREEK ~ TRUES CREEK ~' CONNETOUOT RIVER PENATAQUIT CREEK m )ROWOC CREEK-WEST -- CHAMPL IN CREEK ~ OROWOC CREEK- EAST ,,o YEST BROOK o AWXlA CREEK _~- THOMPSONS CREEK ~- SKOOKWAMS CREEK I I I I I I i , I I I I I I I I i I I I I I I I I I I AS already stated above, the most significant change in the projected aesthetic ratings is expected to be that of Amityville Creek, which is expected to decrease from an original rating of 4.47 to about 2.75. This is a result of the location of this creek at the western end of the study area, where projected decrease in the water table is most pro- nounced. The upper portion of Amityville Creek is expected to dry for several thousand feet. Lower segments of the stream will exhibit a substantial decrease in flow. These conditions would have adverse impacts on all major aesthetic parameters. Impact would be observed along the entire length of the stream, with particularly pronounced impacts in the upper seg- ments and along Avon Lake. woods Creek, projected to exhibit the second largest de- crease in stream aesthetic value, is a relatively short stream also located in the western portion of the study area. Its aesthetic rating is expected to decrease from an originally low rating of 3.18, to about 1.51. This is a lower aesthetic rating than any of the stream ratings under pre-sewering con- ditions. Impacts would be clearly observable along the entire length of the stream. Neguntatogue Creek is expected to exhibit the third larg- est impact. ~owever, the projected decrease of 1.03 in its aesthetic value is substantially lower than those of Amity- ville (1.72) and woods (1.67) Creeks. The uppermost segment of this stream is also expected to dry. Although impacts of the "No Action" alternative would occur along virtually the III-3-9 I I I I I I I I I I I I I I I I I I entire stream length, impacts would be particularly observable in the upper and mid-stream segments of the creek. Carll's River, ranked .third according to the stream aesthetic ratings under pre-sewering conditions, is projected to decrease in aesthetic rating by 0.95 due to post-sewering conditions. Deterioration in stream aesthetics would be ob- servable along the entire length of the river, with pronounced impacts on lakes and ponds. Aesthetic values of vista points along Belmont Lake, for example, are projected to decrease from the original average of 6.05, to 4.27 under the "No Action" alternative. Santapogue Creek, the fifth stream in terms of aesthetic impacts, ia expected to decrease its aesthetic value by 0.91, from 5.40 to 4.49. Upstream segments are projected to dry, with flows in remaining portions of the stream decreasing below the present level. Consequently, the aesthetic values of all vista points along the stream are expected to decrease. Projected impacts tend to decrease Decreases in aesthetic values are projected for a group of five in a downstream direction. ranging from 0.65 to 0.60 streams including Cascade Lakes and Lawrence, Willets, Sampawams and ~reat Neck Creeks. The original (pre-sewering) aesthetic values of these streams ranged from 10.00 for Cascade Lakes, to 4.67 for Great Neck Creek. III-3-10 I I i I I I I ! I I I I I il I I I I 4.0 Recreation Two models for the rating of recreational values were developed streams according to their during Milestone I of this study. One of these models was used to assess recreational ratings of official parks, the other to rate additional ("un- official") recreational areas under pre-sewering conditions. Input parameters of these two models, directly related to streams, were similar and included perimeter of water body, surface area, accessible perimeter and stream aesthetic ratings. These two models were also used in this phase of the study to project new recreational values of the streams for post-sewering conditions under the "No Action" alternative. For this purpose, new values of input parameters were used as predicted by hydrological and hydraulic models. New aesthetic values at relevant vista points as projected by the earlier described aesthetic model, were also utilized. Table III-3-3 presents the resultant recreational ratings of all 22 streams for the pre-sewering and "No Action" conditions. The table also presents the differential between these two ratings indicating the magnitude of the impact. The last column ranks the str'eam according to the magnitude of the impact. Figure III-3-3 depicts relative magnitudes of the im- pacts of no action conditions on recreational values of all streams in a graphical form. Santapogue and Neguntatogue Creeks are expected to ex- hibit the greatest impacts on their recreational ratings. A III-3-11 TABLE III-3-3 SUMMARY TABLE OF STREAM RECREATIONAL RATINGS (NO ACTION) No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 STREAM Name Amityville Creek Woods Creek Great Neck Creek Strong's Creek Neguntatogue Creek Santapogue Creek Carll's River Sampawams Creek Skookwams Creek Willets Creek Trues Creek Thompson's Creek Cascade Lakes Lawrence Creek Watchogue Creek Penataquit Creek Awixa Cree~ Orowoc Creek - West Orowoc Creek - East Champlin Creek West Brook Connetquot River RECREATIONAL NORMALIZED RATING RATING PC NA ~C NA _A RANK 36.27 30.73 5.11 5.03 0.08 6 5.08 3.24 0.91 0.58 0.33 4-5 7.40 7.32 1.31 1.30 0.01 14-15 -0- -0- -0- -0- -0- 16-22 21.41 17.53 3.80 3.11 0.69 2 8.46 4.32 1.49 0.77 0.72 1 396.91 372.68 10.00 9.67 0.33 4-5 63.63 59,37 5.48 5,42 0.06 8 -0- -0- -0- -0- -0- 16-22 10.69 10,32 1.88 1.83 0.05 9 8.40 8.01 1.49 1.42 0.07 7 -0- -0- -0- -0- -0- 16-22 48.00 45.72 5.27 5.24 0.03 10 19.48 17.22 3.44 3.06 0.38 3 -0- -0- -0- -0- -0- 16-22 -0- -0- -0- -0- -0- 16-22 7.61 7.59 1.35 1.3~, -0- 16-22 13,73 13.60 2.43 2,41 0.02 11-13 15.72 15.70 2.79 2.79 -0- 16-22 71.61 70.89 5.59 5.58 0.01 14-15 9.51 9.43 1.69 1.67 0.02 11-13 104.05 102.46 6.03 6.01 0.02 11-13 Notes: PC = NA = Present Conditions Future conditions should no action be taken A Predicted change in normalized rating (=Impact Rank is based on impact due to No Action EI-E-III CHANGE ~N RAT;NG (IMPACT) LAWRENCE CREEK ;ARLL'S RIVER ~WOODS CREEK 'YVILLE CREEK TRUES CREEK SAMPAWAMS CREEK WILLETS CREEK CASCADE LAKES CONNETQUOT RIVER WEST BROOK OROWOC CREEK- WEST CHAMPLIN CREEK GREAT NECK CREEK ,ROWOC CREEK-EAST AWXIA CREEK PENATAQUIT CREEK WATC HOGUE CREEK THOMPSONS CREEK SKOOKWAMS CREEK STRONGS CREEK ~ANTA POGUE CREEK ~IEGUNTATOGUE CREEK I I I I I I I ! I I I I I I I I I I I group of these streams, including Lawrence Creek, Carll's River and Woods Creek are expected to exhibit intermediate im- pacts. Impacts on recreational values of the remaining streams are expected to be. negligible. Only one recreational area was identified on Santagpogue Creek in the immediate vicinity of Beaver Lake. Beaver Lake is located on the upstream reach which is expected to dry if no mitigating action is taken. Although the lake is not ex- pected to disappear totally, its size would be substantially reduced. The aesthetic rating of this lake is projected to de- crease from the original rating of 4.93 to a new rating of 2.65. As a consequence, the recreational rating of Beaver Lake and, therefore, of the entire Santapogue Creek, is pre- dicted to decrease from an original rating of 1.49, to a new rating of 0.77. Feller's Park and Lincoln Avenue Park were two recrea- tional areas identified on Neguntatogue Creek in Milestone I of this study. Feller's Park is located on the uppermost seg- ment of the creek. The upstream segments of Neguntatogue Creek is predicted to dry under the no action condtions. Feller's Pond, located within the park, is expected to reduce in size and the aesthetic rating of the lake is also projected to be reduced. Consequently, the water related recreation in this park is expected to be adversely affected. Lincoln Ave- nue (Lindhurst) Park is located on the downstream reach of the creek. Only minor impact on the recreational value of this park is expected, due to a some what lower aesthetic value of III-3-14 I I I I I I I I I I I I I I I I I I I the stream flowing through the park. The original, relatively low recreational value of 3.80 for Neguntatogue Creek is ex- pected to decrease by 0.69 to a value of 3.11. Two recreational areas were identified on Lawrence Creek in Milestone I. These were unofficial parks surrounding Law- rence and Oconee Lakes. Although these two lakes are not ex- pected to reduce in surface area substantially, their respec- tive recreational values are projected to decrease due to re- duction of their aesthetic values. During the work in Mil- stone I, aesthetics of water bodies in unofficial park areas were found to have a substantial effect on water-related, recreational activities. The recreational rating of Lawrence Creek is projected to be reduced by 0.38 from the original rating of 3.44, to a new rating of 3.06. Carll's River received the highest recreational rating of 10.00 under the pre-sewering conditions. There were nine recreational areas identified on Carll's River during Mile- stone I of this study. Of these, six were official parks and included Belmont Lake Park. The projected decrease by 0.33 in the recreational rating of Carll's River to a new rating of 9.67, is a result of predicted reductions in water surface areas of various lakes and their aesthetc ratings. It should be emphasized, however, that even the projected (reduced) recreational rating of the Carll's River still remains sub- stantially greater than any original rating of all the other streams under the pre-sewering conditions. III-3-15 Recreational activities on woods Creek were observed in the immediate vicintiy of Oakland (woods) Lake. This un- official receational area is expected to decrease its recrea- tional value for residents in the surrounding area due to pro- jected decrease in the lake size and in its aesthetic attrac- tiveness. The recreational value of woods Creek is expected to decrease from the orginal rating of 0.91 to a new rating of 0.58. TABLE III-3-4 SUILMARY TABLE OF SOCIO-ECONOMIC RANKINGS I Stron9's Creek 92 ec ...~ t~c tm 37,756 ~7t031 4,190,916 4,110,441 38,412 37,853 1,421,244 1,400,561 34,733 34,558 1,146,189 1,140,414 36,650 36,363 3,371,800 3,345,396 32,168 31,749 1,994,416 1,968,4~8 34,482 33,935 5,586,884 5,497,513 43,424 43,113 12,071,872 11,985,414 42,84] 42,184 13,152,80~ 12,950,488 3.19 3.13 .06 4 1.08 1.06 .02 6-10 0.87 0.07 -0- 15-22 2.56 2.54 .02 6-10 1.52 1.50 .02 6-10 4.25 4.18 .07 2-3 10.00 9.85 .15 1.39 1.39 -0- 15-22 2.68 2.64 .04 5 2.78 2.77 .01 11-14 1.49 1.49 -0- 15-22 3,02 3.00 .02 6-10 1.80 1,78 .02 6-10 0.66 0.66 -0- 15-22 1.58 1.58 -0- 15-22 5.68 5.67 .01 11-14 -0- 0.00 -0- 15-22 -0- 0.00 -0- 15-22 Hotes~ PC - Present Conditions A = Predicted Change in Normalized Re,in8 (=l~oact) I 6I-£-III CHANGE IN RATING ( IMPAC~ I I I I I ~ SAMPAWAMS CREEK I ?~'~ "'~" ~ ! TWOOOS C.E~__ . 09 LAWRENCE CREEK ~ ~ T ~ I m SKOOKWAMS CREEK ~D · · THOMPSONS CREEK rtl CREEK 09 m WATCHOGUE AWXIA CREEK ~ r- ! OROWOC CREEK-EAST C WEST BROOK 09 'CONNETQUOT RIVER m I I I I I .I I ! I I I I I I I I I I I 6.0 Water Qualit~ The Water Quality Index model developed by the National Sanitation Foundation (NSF) was used in Milestone I of this study to assess water quality ratings of the 22 streams. The stream water quality data collected in 1978 and 1979 were used as input into the model. In order to assess changes in water quality parameters of the streams due to projected decreases in the water table and stream flows, stream models were developed and run by Tetra- Tech, Inc. Results obtained from these models indicate that only negligible changes in water quality parameters can be ex- pected. Consequently, no changes in the water quality ratings of the streams were projected based on the NSF Water Quality Index model. III-3-20 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1 11 11 ,12 12 13 4 o 73 27,3 o ,s'oo.~ l 4 15 15 ~- 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28" 28 29 29 30 30 31 31 % 32 32 33 33 ~8 4O 48 49 $! $~ I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 SCALE1:48000 2 1 ~ 0 1 2 3 4 5 6 MILES 2 1 ]/2 0 1 5 KILOMETERS 2 3 4 6 Base from U.S. Geological Survey 1:24,000 series: Amityville,N.Y., 1969; Bayshore East, N.Y.,1967; Bayshore West, N.Y,, [969; Central Islip, N.Y., [967; Greenlawn, N.Y., [967; Huntington, N.Y.,i967; Patchogue, N.Y., [967; Sayville, N.Y., [967