Designing
systems at a commercial
requires coordination between
developers,
engineers and landscape architects from the inception of the
design process. The information below is provided to inform
designers and engineers of the assumptions and methods the city recommends for use in designing and engineering water harvesting for a commercial
. This approach can be used both in preparation of the two components of the
Harvesting Plan: the
Water Budget and the Water Harvesting Implementation Plan.
Preparing a
Water Budget that meets the requirements of Commercial
Harvesting Ordinance and Technical Standard 4-01 requires projecting yearly plant water demand for the
landscape then determining how much harvested water supply is needed to meet at least 50% of this demand.
may choose to use
(earthworks),
(tanks), or a combination of both methods to accomplish this goal. Because most
will be able to accomplish the 50% goals with
alone, the
design calculations provided at the end of this exhibit focus on data for
sites. An example
Water Budget is shown in Table A-1. This example is provided to serve as a model for
undertaking
design. An excel spreadsheet of this water budget is available from <http://www.tucsonaz.gov/PDSD/What_s_New/what_s_new.html> for use by
designers in preparing their
Water Budget. This information in turn should be used to prepare the
Implementation Plan. Calculations