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HomeMy WebLinkAbout26 - Bayview Heights Drainage Improvement - PowerPoint (Public)BAYVIEW STORM DRAIN SYSTEM PROJECT FUNDING 27 ACRE DRAINAGE AREA November 12, 2014 Agenda Item No. 26 COUNCIL IS REQUESTED TO APPROVE THE FOLLOWING FUNDING SCHEDULE: 1. OCTA funding construction costs up to grant amount — Approximately 300K. 2. OCTA funding 30K in engineering costs 3. County Parks funding 50K in engineering costs 4. Nearby affected property owners paying 25K each for a total of 50K 5. City funds remaining costs. J� J M 1) The affected tributary drainage area is located in the Bayview Heights Community, which encompasses approximately 27 acres of watershed area. 2) The storm drain will be backfilled to match adjacent grades and planted with native -type vegetation as approved by the resource agencies. J� J M 3) A natural treatment wetland will be constructed at the lower reaches of the project. 4) The wetland will be designed to remove pollutants and trap sediment before entering the Upper Newport Bay to improve water quality. 5) The new system will process the raw discharge from an existing storm drain outlet and direct the flow to a riparian natural treatment system -- effectively stopping the large quantities of sediment and pollutants currently dumping into the Upper Newport Bay Ecological Reserve, 6) This system will act as a natural filtering plant for urban runoff from the streets of the Bayview Heights community, which was annexed into the City of Newport Beach in January of 2002. 7) The affected runoff and system will capture metals, sediment and other pollutants found in the streets and trap these pollutants loads before they enter into sensitive marsh and mudflat areas along the Upper Newport Bay. 8) The system will stop the erosion of native soils and the entry of thousands of cubic yards of sediment into the into the Upper Newport Bay. i V 9) The eroded zones will be restored to original elevations and revegetated with a diverse array of native plants, thereby enhancing the natural habitat which will lead to better habitat for birds (e.g. Anna's hummingbird), small reptiles and amphibians (e.g. western fence lizard and Pacific tree frog) , and invertebrates, including various species of of butterflies. 10) The constructed wetlands will have intermittent flows and will also provide habitat for cattails, sedges and native herbs. 1 1) The project will significantly improve the water quality and reduce the amount of both dry weather and storm water flows into the Upper Newport Bay. The project will eliminate future erosion by conveying flows into an underground storm drain which will outlet into an energy dissipater that will enter into bioswales before reaching the bay. Eroded areas will be replanted with native vegetation. 12) In 2010, the ACOE spent over $50 million dollars dredging 100,000 cubic yards of mud from the Bay. This work will reduce future dredging. 13) The partners of this project are dedicated to improving the water quality and natural habitat for the Upper Newport Bay and surrounding areas. CURRENT LEGAL LIABILITY OF CITY TO PROPERTY OWNERS ELIMINATED Public Entity Liability: A public entity can be liable for negligence or inverse condemnation for stormwater discharges from a public improvement. If the source of the uphill stormwater is a public improvement (for example, a drain or pipe owned or maintained by a public entity), the public entity can be held liable for damages under the modified civil rule discussed above. In addition, the public entity can be held liable under an inverse condemnation theory. "Inverse condemnation liability ultimately rests on the notion that the private individual should not be required to bear a disproportionate share of the costs of a public improvement."" Under this cause of action, the downhill owner would be required to prove that the public entity's conduct with regard to its public improvements posed an unreasonable risk of harm to the downhill property, and that the public improvements were a substantial cause (but not necessarily the sole cause) of the damage to the downhill property.' Article Excerpt From: http: / /www.beriiner.com /article /Who_is_ Responsible_ When_ Uphill_ Stormwater _Causes_Downhill_Damage Asa- 0.Jpf x; Now part u 4 .�4 r •A� YI F l . Ir• p• 4 � � - m Pr m Y � � � � � • � f W � � e r a s fd a I el, e a F LLI T 4 F r � n —rte . —t — ;'S rF K � 1• r '� T .`— 4 . K �r • , �-•Y•. -ti. �- -�-_ - or "l. Via-_- kT T �-�. - .,:_.� _ �� �_ - - 4 14 Aft im 6. I V ..J .i tpr jr R ;? u'r rI � �.�. ' {o-- r;.'E R _� �:r .. , dt. a �' �). T � �I n � � App 1�]y�}' % . '���'� �. h�: � � : ,� ` ��, 3 ti. t; a�� �v .R -_ ». ��-� ,h i r .� W. r p` E WIN- � r V � J 11�a IF tik 9 1 ♦ � Y nl 'H,'a 11 /7.. 1 .� V ) I ♦ far ; •X}q !. il. r ,1 ! e �.. I4a r yr4yyiy' � b t � 4 yam} ➢„� � " �, ,.50 " _ ''_ �,'_ � - -f ' •7 � 9F. 4W If N ir j _ s � 1 J