BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

etc.) and chemical (dissolved oxygen, etc.) parameters might be important toexamine using correlation and regression statistics. 91The next step in data interpretation is conducting the proper analysis andinterpretation to ensure that the assumptions on which the data retrieval planwas based are still valid. New information or failure to collect all the datarequired in the original experimental design may necessitate modification. Ifdata analysis can proceed according to plan, decide to accept or reject the testedhypothesis. Following this step, an effort should be made to identify additionalquantitative or qualitative conclusions that may be warranted, and explore anyadditional hypotheses that may be tested using the same data. Do not limitconclusions to acceptance or rejection of hypotheses, but extend clearexpression of the implications of the observed results. Decision makers who arenot technical specialists may fail to grasp these implications unless they areclearly communicated. 92The following are the likely order of priority for physical baselinemeasurement and monitoring for a reviewing a proposal for a proposed newbackshore protective structure:• Backshore position and evolution, rate and lateral extent of erosion, rate ofrecovery following erosion• Sediment distribution and variability, both spatially and temporally• Water levels, nearshore waves and winds• Littoral and terrestrial geomorphology and hillslope analysis of adjacentcliffs, underlying foreshore strata and nearshore lakebed substrate features• Variations in backshore groundwater levels (effects to backshore wetlandsand SEZ)• State and regional water quality parametersInclude reference sites representative of the “without-project” condition (e.g.the same geomorphic setting and no protective structure) in the monitoringprogram, if possible. The purpose of reference sites is to evaluate changes thatoccur through time but are not related to the project. Without reference sites itis often very difficult to establish that observed changes are project related, anda question may remain as to whether natural variability or other perturbationswere responsible for observed changes. In some cases, it may be possible tocontrol for other perturbations by establishing more than one reference site.Reference sites may also be used to ensure that changes, which occur within91USACE, 1989, EM 1110-2 -5025, Environmental Engineering for Coastal Shore Protection92USACE, 1989, EM 1110-2 -5025, Environmental Engineering for Coastal Shore Protection andUSACE, 2008, Coastal Engineering Manual - Parts I-6CHAPTER 8: Shorezone Protective Structures and BMPsTRPA BMP HandbookPage 8-90 2012