: OpportunitiesCayuga for Inlet Restoring Dredge Ecosystem Functions Material & Services
Fall 2011 Cornell University Restoration Ecology Class Report Table of Contents:
Brick Production 47 Introduction: Methane Analysis: Amy McLean Executive Summary 4 Methane Production in Inlet Ben Hedstrom Sediments: Spatial Variability and Lightweight Aggregate 49 Alternatives for Mitigation 30 Amy McLean Jack Mascharka, Rebecca Montross, Nadia Project Introduction 5 Pierrehumbert Cement Lock® Tim Lynch 50 Amy McLean Hydrilla verticillata: Watershed: Managing Hydrilla verticillata for the Dry Sites: Southern Cayuga Lake Watershed 9 Introduction 51 Matthew Gonser Cayuga Inlet 36 Matthew Horvath Trinity Boisvert & Yong Seuk “Peter” Kwon Dredge Material Analysis: Cornell Lake Source Cooling Project: Alternatives & Reference Dryden, NY 52 Dredge Material 16 Becky Mikulay Jamie Nassar & Hayden Stebbins Sites: Introduction 44 Times Beach: Buffalo, NY 53 Dryden Site Plan Communities 26 Gene Fifer Andrew Miller Becky Mikulay, Jamie Nassar & Hayden Stebbins Industrial Products: Cuyahoga River & Dike 14: Cleveland, OH 54 Introduction 45 Andrew Miller Matthew Horvath Dredge Infill Project at Stewart Park: Synthetic Soils 46 Ithaca, NY 56 Becky Mikulay Becky Mikulay
2 Dredge Infill Project at Cass Park: Appendices: Ithaca, NY 58 A: Landslide Susceptibility Becky Mikulay Analysis Methods 67 Wetland Sites: B Soil Health Test Results 68 Introduction 59 Gene Fifer C: Dryden Site Species Curves 69 Manning and Cowett Proposal at Stewart & Cass Park 60 Acknowledgments: 72 Amy McLean Poplar Island: Chesapeake Bay, MD 62 Amy McLean Living Shorelines: St. Michaels, MD 64 Amy McLean Montezuma National Wildlife Refuge: Seneca Falls, NY 65 Gene Fifer Catherine Creek Natural Area: Watkins Glen, NY 66 Gene Fifer
3 Executive Summary: Ben Hedstrom
Our Restoration Ecology class ed medium for food production. With more to the plan to dredge the inlet. Given that (consisting of undergraduate and graduate intensive testing, and mixing it with other some reports indicate Hydrilla can live for students in the schools of Earth Systems soil or compost, much of the material could up to five years in dry material, the current Science, Natural and Environmental potentially be used in this way. plan to store dewatering dredge material Systems, Landscape Architecture, and City Previous studies have indicated that for one year with subsequent use across the and Regional Planning) spent the Fall 2011 the dredge material is a silty-clay, but we landscape has a great potential to proliferate semester investigating the Cayuga Inlet have found it is actually more a sandy-loam. the infestation in waterways throughout the Dredging Project and the complications This material contains a higher percentage of county. Solarization, a method of soil steril- it has faced with the discovery of Hydrilla organic material than was expected and has ization beneath plastic sheeting, is potential- verticillata. Doctor Thomas Whitlow of the ability to support terrestrial plant spe- ly more effective at killing Hydrilla than mere the Cornell University Department of cies similar to those found on a 12-year old drying. Horticulture led this course. dredge disposal site in Dryden. The material Simultaneously, certain areas of the Our report includes findings from we tested has low aggregate stability and inlet should potentially be managed indi- studies on local dredge material, Hydrilla, would make a poor structural material. vidually, namely Cascadilla Creek. Under the the southern Cayuga Lake watershed, and Additionally, we measured the dredge conditions encountered this October, our several case studies on successful projects material’s potential to release methane into light extinction readings show that below involving the productive reuse of dredge the atmosphere. The overall anthropogenic 2.5 feet, light intensity is below the light material. impact would be small compared to releases compensation point and would be unlikely to from local dairy operations, even given the support vigorous stands of Hydrilla. Howev- Dredge Material largest scope of the dredging project. er, since Cascadilla Creek and the small tribu- At the Cornell Soil Health Lab, we tary creek across the Inlet in Cass Park are analyzed samples of local dredge material for Hydrilla verticillata shallow and generally have clear water, they many qualities including toxicity and poten- Samples of Hydrilla verticillata were are more prone to infestation and a separate tial use as a plant growing or structural mate- tested over a period of several weeks for management plan should be created for any rial. While restricted access to the inlet was a desiccation tolerance to understand the spe- dredge material from these areas. limitation to our study, our findings conclude cies’ survival ability in dewatered dredge ma- that this material is not generally hazardous terial. Generally, our tests indicate that short Our Local Watershed and the existing nutrient levels are self-stabi- term desiccation alone cannot kill Hydrilla. Sedimentation in the inlet is a natural lizing. There do however appear to be local A management plan for Hydrilla eradication geomorphologic process that has existed ‘hotspots’ for lead so it is not a recommend- should absolutely be made in conjunction since the end of the glacial retreat. Human
Introduction 4 activity has accelerated the pre-settlement • Use the dredge material in ecologically condition. Replacing our native flood plain and economically productive ways. “If we don’t allow someone to try something and wetland habitats at the outfalls of • Define an efficient plan for the future that to see if it works, how will we move ahead?” tributaries at the south end of the lake with understands sedimentation in the inlet as paved or turf surfaces, and stripping stream a persistent issue. Mark Sudol edges of bank-stabilizing vegetation for de- • Increase project innovation utilizing the USACOE Regulatory Program Chief velopment over the past century decreases expertise of diverse agencies and levels Science Magazine, April 2008 functionality to the already accreting system. of government. While our analysis of area forest cover levels indicate that there may be slightly lower lev- While we probably do not need to restore els of sediment in the future due to decreas- the channel to its original configuration for ing levels of farming, history has shown that the maximum potentials of navigability, sedimentation will continue to occur. recreation, and flood-control, our legacy to Dating back to the sand bar that was the Cayuga Inlet Dredging Project should aim removed from the inlet at the beginning of to create a better situation than the one that the nineteenth century to allow boat traffic, has materialized. dredging has been a part of Ithaca’s history Potentially a wetland site, with small and will remain so as long as humans need to cells that could easily be monitored and navigate the waterfront. Our recent tenden- solarized, with installation of a silt fence to cy to defer maintenance demonstrates that retain Hydrilla from other parts of the lake, perhaps a lack of action is the most signifi- remains the most viable option. Similar to cant effect of humans on the inlet. Poplar Island, but on a much smaller scale, At this time, we have a chance and a this plan has the highest ability to confine duty to make human actions that attempt to the material, while creating a new species relieve this situation and instigate a plan that habitat and still limiting the distance material works with the evident natural process. Our would travel. report provides several practical and success- ful examples of productive dredge use and restoration projects that collectively describe opportunities to:
Introduction 5 Project Introduction: Tim Lynch
The City of Ithaca is in the planning will use earthen berms to create multiple Report and approval stage for a dredging project cells for the processing of dredge material This report was produced by Cornell that will remove accumulated sediment from at different stages of dewatering. The Draft University students as part of a semester the inlet. The inlet consists of the Cascadilla Environmental Impact Statement (DEIS) pre- long study of the dredge project as part of Creek, Cayuga Inlet and the Flood Control pared for the City by Ecologic LLC estimates a Restoration Ecology (HORT 4400) class Works. These three entities perform a variety that the SMF would have an annual process- taught by Professor Tom Whitlow. The of ecological, infrastructural, commercial ing capacity of 80,000 cubic yards. The DEIS report intends to summarize the findings of and recreational functions. The Army Corps proposes utilizing this material for a variety the class research on this subject, to provide of Engineers has estimated that a total of beneficial re-uses including habitat resto- the Ithaca Community with information per- of 660,000 cubic yards of sediment have ration and being mixed with yard waste to tinent to the dredge project, to investigate accumulated within the channels. The City produce topsoil. The City does not currently the possible beneficial uses of the dredge will be collaborating with multiple agencies have a firm plan for the beneficial re-use of material and to add to the body of knowl- including the US Army Corps of Engineers material. edge related to the aquatic invasive Hydrilla (ACOE), New York State Department of The city plans to construct the SMF verticillata. Environmental Conservation (NYSDEC) beginning in the spring of 2012 and begin the and the New York State Canal Corporation first stage of the project with the dredging of Regional Geologic History (NYSCC). an estimated 25,000 cubic yards of sediment The processes of erosion and sedi- The city is currently planning a de- from the Cascadilla Creek section of the Inlet. mentation have been an integral part of watering facility to be located on a 23-acre The DEIS submitted by the City of Ithaca in the natural history of the central NY region. portion of city owned land behind Lowe’s November of 2011 involves this initial stage Prior to the Ice Age, the Finger Lakes were and Wal-Mart known as the Southwest Site. of the larger planned project and the related north flowing rivers that were fed by a series This Sediment Management Facility (SMF) construction of the SMF. of perpendicular streams. The rivers were
Our Class Visit to the Southwest Dewatering Site, September 2011
Introduction 6 deepened and widened by the glaciers and of large areas of cattails and other aquatic Control Channel that was begun 30 years the stream valleys were filled with glacial plants. Decades of filling, bulwark construc- later in 1965 and completed in 1970. A major debris. Since the retreat of the glaciers, tion and channelization created the inlet in dredge in 1982 removed over 200,000 yards these streams have been constantly moving its current form. of material that was used to create the Hog’s this debris into the lake and have formed the Hole Natural Wildlife Area in Allen H. Tre- gorges unique to the area. man Marine Park. In 1999 the ACOE removed 75,000 CY from the flood control channel.
Dredging Process The current plan for the inlet dredg- ing is to use a hydraulic dredge rather than the mechanical dredge method used for the Lake Source Project. Hydraulic dredging is a vacuum process that mixes water with the material to create a slurry mix that has the ability to be pumped. There are cost ad- Renwick Marsh, 1906 (Ithaca Historical Society) vantages to this method and it reduces the Dredge in Cayuga Inlet near Cascadilla Creek, early 1900’s immediate trucking of material. The primary (Ithaca Historical Society) Inlet History and Flooding disadvantage is that it requires an extended During the nineteenth and early- Dredging History period of time and a large site for the dewa- twentieth centuries the inlet experienced Over the last two centuries the inlet tering process. a massive amount of man-made altera- has been dredged and re-configured as part tions. Significant de-forestation of the area of different projects that aimed to improve Lake Source Cooling Precedent Project led to soil destabilization and subsequent navigability and in attempt to control the Also in 1999, Cornell University erosion within the watershed as well to as common occurrence of flooding. Between dredged 3,000 CY of material from the an increase in flood occurrence and dam- 1860 and 1900 the inlet was dredged on sev- southeast of Cayuga Lake as part of the Lake age. At the same time, development of the eral occasions to maintain a depth of seven Source Cooling project. This project used a floodplain continued into Renwick Marsh, feet. Between 1910 and 1965 the inlet was clamshell dredge to mechanically remove now known as Tompkins Park. At the turn of dredged every 20-25 years. The severe flood material. This allowed the dewatering to oc- the twentieth-century, the marsh consisted of 1935 set in motion the plans for the Flood cur within hours on shore in containers. The
Introduction 7 material was then truck transported to a site Hydrilla verticillata References in Dryden. The recent discovery of the aquatic Armstrong, Victoria. A Cultural History Sur- invasive Hydrilla verticillata proposes ad- vey of the Cayuga Waterfront. Print. Dredge Material ditional challenges to the Ithaca Inlet. The The class was able to use the Dryden highly invasive species has to potential to “Ithaca Dredging Project Website.” EcoLogic site to test the different properties of the create major disruption to the ecology of the LLC. EcoLogic LLC, Nov. 2011. Web. 11 Dec. dredge material using the existing material inlet and Cayuga Lake and to have a negative 2011.
Introduction 8