The policies contained herein outline the requirements for a Storm Water Management Report. Not all of the sections of this outline may apply to a proposed development. It will depend on the size of the proposed development, the existing site conditions, and the proposed land use of the development.
These guidelines shall not limit the right of the City Engineer to impose at any time additional, more stringent requirements based on the site circumstances. Nor, shall these guidelines limit the right of the City Engineer to waive, in writing, individual requirements based on the site circumstances.
The Storm Water Management Report should be submitted with the Site Plan for commercial and industrial sites. It should be submitted with the Construction Drawings for condominium developments, planned developments, and subdivisions. Questions regarding the Storm Water Management Report should be directed to the City Engineer.
The Report should contain a description of the existing conditions on site, land usage, ground cover conditions, soil types, etc. The Report should explain the proposed improvements and the intent of the storm water management measures being proposed. The Report should be prepared in a neat and organized manner. The Report should provide maps and drawings, as necessary, to support the Report’s calculations. The Report should verify that the information contained on such maps and drawings corresponds to the information provided in the rest of the Report.
As a minimum general requirement, the proposed storm water management measures shall be designed such that the runoff from the site shall not flood existing or proposed structures, cause the loss of property, endanger individuals, or cause the loss of life.
Upstream runoff from outside the development area should be conveyed through the site as closely as possible with the current runoff conditions. Existing drainage features such as swales, ditches, creeks, and ravines, conveying upstream runoff shall remain. Easements for drainage features shall be provided as outlined herein.
Provide positive grading for runoff for all lots and groups of lots within condominium developments, planned developments, and subdivisions, as well as for the overall site. Runoff for all development sites and individual lots within a development shall be conveyed in an approved manner to an adequate and appropriate discharge point (except as provided for permanent retention areas).
Wherever possible and practical, a developer is encouraged to use measures to slow the storm water runoff rate by increasing friction. Some examples are discharging roof water to vegetated areas on site, using grass and rock-lined drainage channels, and creating grass strips between areas of sheet flow runoff such as parking lots. Additionally, developers are encouraged to reduce the total runoff volume by means of infiltration. Some examples are infiltration basins, infiltration trenches, dry basins, and the use of retention basins instead of detention basins.