Appendix 4- SWMP

                                                                                                           ingeniir

EXECUTIVE SUMMARY

Ingeniir Pty Ltd (Ingeniir) have been engaged by Michael & Donna Grace to produce this Stormwater
Management Plan (SMP) in support of the Material Change of Use application for the Proposed Duplex at 20
Ventura Street Sunrise Beach 4567, Lot 91 on RP132135.

This report is comprised of stormwater quantity and quality assessments. The quantity assessment is
undertaken to confirm a ‘non-worsening’ discharge of peak flow from the developed site. The quality
assessment is undertaken to determine the required stormwater treatment measures to be implemented on
site to comply with Local and State Authority requirements.

Stormwater Quantity Calculations consider storm events up to and including the 1% AEP and 1% AEP at the
year 2100 storm event (adopted increase of 120%). The purpose is to ensure that the existing infrastructure
and/or downstream properties are not adversely affected by the proposed development.

The stormwater quantity assessment determined that a measurable increase to the impervious area will
occur due to the proposed development which would result in an increase to peak discharge rates if no flow
mitigation were implemented. On-site detention measures are proposed for this development to maintain or
improve on pre-development peak stormwater discharge rates.

Currently no quality stormwater management measures are in place for the existing subject site. As the
proposed development area is less than 2500m2; best-management practice for stormwater treatment
measures are to be implemented on site in accordance with current Industry Best Practice, WSUD Engineering
Guidelines and State and Local Stormwater Quality Objectives.

All relevant standards and guidelines are addressed in this Stormwater Management Plan including;
criteria from the Sunshine Coast Regional Council Planning Scheme Policy, Queensland Urban Stormwater
Quality Planning Guidelines (2010), Queensland Urban Drainage Manual (QUDM) and the Australian Rainfall
and Runoff Guidelines.




                                              Ingeniir Pty Ltd | 245001-SMP-01
                ABN: 99 642 485 363 | PO Box 988 Maroochydore QLD 4558 | [email protected] | 0404157187
                                                         Page 3 | 15