Mr. Hennessy’s practice focuses on administrative, environmental, governmental and land use law, with particular experience in litigation in those areas of law.
Areas of Practice
Has more than 30 years of experience representing clients in the negotiation and litigation of environmental permitting and enforcement issues, land development, coastal construction matters, water rights, hazardous waste, wetland issues, property rights and eminent domain.
Represents clients before all courts in Florida, including the Florida Supreme Court, the 11th Circuit U.S. Court of Appeals, the federal district courts, and the U.S. Supreme Court.
Publications and Presentations
Frequent lecturer on topics including coastal construction, water law, endangered species, administrative law and environmental litigation
How To Be An Effective Expert Witness, LLW Lunch & Learn, May 2018
Nuts and Bolts of Permit Challenges, co-presented with Susan Roeder Martin, Environmental and Land Use Law Section of the Florida Bar, February 2018
Sovereign Submerged Lands Permitting and Development in the Coastal Marine Environment, Florida Chamber Environmental Permitting Summer School, July 2017
Litigation Advice for the Land Use Practitioner: Hope for the Best, Prepare for the Worst, Environmental and Land Use Law Section of the Florida Bar Live Webcast, December 2016
Extreme Environmental People Skills, Florida Chamber Environmental Permitting Summer School, 2008-2016
Seeing the Complete FOG Picture, Journal AWWA, January 2014
U.S. Supreme Court Offers Clean Water Act Plaintiffs Their Day in Court, co-authored with Tara Duhy, Journal AWWA, June 2012
Are City Governments and Social Media a Good Match?, Quality Cities Magazine, February 2012
What You Gonna Do when the Well Runs Dry: Protection of Rights to ASR Water, ABA Water Resources Committee Newsletter, Vol. 12, No. 2, co-authored with R. David Jackson, Esq., January 2010
Aquifer Storage and Recovery, Vail Water Law Conference, January 2010
Greenwashing: A Guide to the Ethical Advertising of Green Products, co-authored with Michelle Diffenderfer, Esq., Manatee Chamber, December 2009
The Lower St. John’s River Basin Management Action Plan: Assessing Agricultural, Local Government and Environmental Perspectives, co-presented with Tatiana Borisova, Laila Racevskis, Jennison Kipp, Debra Butler and Diana Ferguson, NRLI Practicum Presentation, November 2009
Coastal Construction Below the Mean High-Water Line, The Florida Bar, February 2001
Thirty-Year Erosion Zone, Florida Environmental and Land Use Law Treatise, February 2001
Professional, Civic and Community Involvement
Admitted to the U.S. District Courts for the Northern, Middle and Southern Districts of Florida
Martindale Hubbell AV® Preeminent™ Peer Review Rated
American Bar Association, Section of Environment, Energy, and Resources, Member
The Florida Bar, Environmental and Land Use Law Section, Member
Manatee County Bar Association, former Director
St. Petersburg Chamber of Commerce, Chair of the Transportation Committee and Member of the Sustainability Committee.
Leadership Pinellas, Class of 2020
St. Petersburg Bar Association, Wellness Committee, Member
University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) Natural Resource Leadership Institute, Fellow, 2008-2009
Firm Representative to the Environmental Law Network