Stonnwater management systems for new urban development have been traditionally designed and analyzed with the aid of computer models employing design stonn events [such as the Soil Conservation Service (SCS) temporal distribution], rather than continuous modeling using long tenn historical rainfall data and associated frequency analyses. It has generally been accepted that the latter method provides a more rigorous and realistic design; however, the differences in the results (i.e. designs) generated by the two methods have not typically been understood during the planning and design process. Tlus chapter describes a case study in the Town of Milton (Sixteen Mile Creek Watershed) in which, based on a unique oppotiunity, both methods were applied in the analysis and preliminary design of end-of-pipe stonnwater management facilities. The different flow and storage regimes generated by the alternate methods are highlighted, along with a number of modeling and physical factors which are considered to contribute to the differing results.

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Dwindling resources and social incompatibilities are two of the key reasons why land developers often encounter difficulties in implementing stormwater management facilities on their land, in, or adjacent to existing communities (i.e. NIMBY). Public works departments are concerned with the cost of maintaining a growing number of geographically disparate facilities. Developers are concerned with the costs of construction. and the often greater cost oflanddedication for facilities. Community residents, particularly those already in the neighbourhood, are concerned with safety, odour, aesthetics, and taxes. The simple solution is to avoid the problem altogether by integrating the land use and infrastructure planning process. Unfortunately, in many if not most circumstances, planning decisions have already been committed to, and in some cases (i.e. in-fill situations) master planning may never become a reality. This chapter describes a case study, which through intensive stakeholder consultation and comprehensive alternative screening, has resulted in a superior stormwater management proposal, addressing the concerns of the municipality, development community and public. The analysis and documentation procedures are necessarily more comprehensive, in order to address the broader-based issues of additional stakeholders. The results however, in terms of economics, physical environment and social acceptance, are in some instances considered superior to conventional stormwater practice.

Many agencies and stakeholders in the Regional Municipality of HamiltonWentworth have long recognized the need for watershed planning, particularly for the Red Hill Creek watershed, located in the City of Hamilton's east end. Watershed planning allows for comprehensive and holistic assessment of resources, impacts and mitigation. In 1996, the Region initiated Phase One Data Collection activities to support the preparation of a watershed formally initiated in 1997 to be completed by mid-1998.T'ne watershed pian focused on a series of action plans addressing issues aJl.d concerns raised by stakeholders and agencies. A multi-disciplinary team of experts and stakeholders addressed a comprehensive list of areas including t1sheries, terrestrial resources, surface and groundwater characteristics and quality, stream morphology, cultural heritage, air qualiPf, and contaminant sources.Methods were developed to define the current state ofthe watershed, as well a.' > to evaluate the changes arising from future activity. This chapter focuses on how in-stream water quality \.Vas assessed under the various land use and management conditions considered.

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