Mr. Clar is a senior water resources engineer with more than 30 years of experience in the evaluation, development and application of innovative stormwater management technology. He assembled and led the team that developed the Bioretention/rain garden BMP for Prince George's County (1993) and was a member of the team that developed Low Impact Development Technology in Prince George's County, Maryland (1997).

He is past chair of the Urban Water Resources Research Council (UWRRC) of the American Society of Civil Engineers (ASCE). In 2000 he formed and serves as chair of the UWRRC National LID/GSI Committee and has been involved in planning nine National LID Conferences including;

As chair of the LIDGSI committee he helped to form and coordinates the activities of several task committees, incluiidng;Bioretention Technology; LID Model Ordinance; LID Computational Methods; Permeable Pavements; Rainwater Harvesting; Green Roofs; Green Streets; and LID for CSO

Mr. Clar designed and provided construction supervision for one of the first LID subdivisions in the US, The Pembroke Woods subdivision in Frederick County, MD. He has worked on numerous LID applications including the development on and LID Master Concept Plan for the Oklahoma State University Research Campus.

He has authored and contributed to numerous publications related to LID/ESD, including: The Prince Georges County Bioretention Design Manual, 1993; The Prince George's county LID Design Manual, 1998; The US EPA document, Low-Impact Development Design Strategies: An Integrated Design Approach, 2000; Low impact Development: New and Continuing Applications. Proceedings of the Second national conference on Low Impact Developmen; and numerous book chapters, manuals of practice and technical papers.

Prior to joining Tetra Tech, he served 7 years as the assistant County Engineer for New Castle County, DE, where he supervised Low Impact Development Technology: Implementation and Economics.Proceedings of the 2011 ID Conference , Philadelphia, PA; Low Impact Development Technology: Design Methods and caseStudies. Proceedings of the 2011 LID Conference , Philadelphia, PA; and Permeable Pavements, American Society of Civil Engineers, 2015.