A diverse community of abundant, native amphibians is persisting along waterways of urban and urbanizing Tucson. Community and government leaders in Tucson support the concept of urban amphibian conservation in principle. Meanwhile, concurrent, commingled plans for infrastructure improvements and ecological restoration along major urban riparian corridors are being developed under leadership from Pima County, City of Tucson, and U.S. Army Corps of Engineers.

Paradoxically, as this work gets underway, it could impact local amphibian populations – temporarily via direct earth-moving impacts, and permanently via elimination of seasonal waters in which amphibians breed. Pima County wishes to minimize these negative impacts, and to learn how to protect, manage and improve habitat conditions for native amphibians. This report describes means by which—despite complex public health issues—such conservation may be possible with proper planning.

This Technical Data notebook has been prepared for a Letter of Map Revision application for a portion of the Via Entrada Wash located in Pima County, Arizona. The objective of the TDN and LOMR submission is provide regulatory discharge rates and floodplain limits along the Via Entrada Wash using better topographic, hydrologic, and hydraulic data.