טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentShalev Shai
SubjectStormwater Management in an Urban Neighborhood Following
Water Sensitive Planning principles: Comparison
of Alternatives in Givat Zemer on
Mount Carmel
DepartmentDepartment of Civil and Environmental Engineering
Supervisors Professor Emeritus Uri Shamir
Professor Emeritus Naomi Carmon
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

Development and construction in previously undeveloped spaces increase the volume and discharge of runoff, reduce percolation into the groundwater, increase flooding and damage downstream, and affect the flow in streams. The objective of this investigation has been to examine and evaluate Water Sensitive Planning practices that can mitigate some of these negative effects, in the planned Givat Zemer neighborhood on Mount Carmel in Haifa.

Four alternative development plans were compared: (1) the original plan by the Haifa Municipality; (1A) the same plan with the addition of BMPs - land cover changes that increase infiltration in the basin and structures that reduce discharge at its outlet; (2) our proposed alternative plan, based on a different spatial arrangement of the same land uses, where those with high runoff producing potential were placed at the top of the basin and the more permeable ones further downstream, such that runoff generated by the impervious areas upstream has a chance of being infiltrated downstream, and changing the street pattern to increase the runoff flow path and thus reduce peak discharges; (2A) the same plan with the addition of the same BMPs as in 1A. Storm runoff volumes were calculated with a Distributed SCS model (DSCS), developed in this study, which is an improvement of the well-known and accepted SCS model; DSCS takes into consideration the location of the different land uses in the basin and their relative position in the runoff flow pattern. Peak discharge was calculated by the Rational Formula. The analysis was carried out for different rain storm thicknesses and for a population of storms measured over a period of three years. The conclusions are:

?         Planning based on concentrating the permeable areas at the bottom of the developed area is more effective and produces less runoff volume than the one based on increasing the infiltration capacity of the different land uses. This layout results in a reduction of the annual runoff volume to 20%-50% of the volume generated by alternative 1, while alternative 1A reduces the volume to 60% of that in alternative 1.

?         A combination of rearranging land uses and adding BMPs can reduce the peak discharges exiting the neighborhood to their pre-development values.

Recommendations were drawn regarding the benefit of using the DSCS, the need to improve data collection and analysis on rainfall and soils, and especially the imperative to test the performance of BMPs in pilot projects.