Loading...
HomeMy WebLinkAbout12-06-2011, SS2- WINTER WEATHER PREPcouncil ,j aGenba RepoRt Meeting Date 12-6-1 1 Item Numbe r ...5s a C I T Y O F S A N L U I S O B I S P O FROM : Jay D . Walter, Director of Public Work s Michael Codron, Assistant City Manage r PREPARED BY : Barbara Lynch, City Engineer, Neil Havlik, Natural Resource Manager , Bud Nance, Wastewater Collections Supervisor, Hal Hannula, Supervisin g Civil Enginee r SUBJECT : 2011-12 CITYWIDE WINTER WEATHER PREPARATIO N RECOMMENDATIO N Receive and file a report on the City's 2011-12 winter weather preparations . DISCUSSION Backgroun d Each year City staff completes a variety of activities to prepare the City creeks and storm drain s for winter and to reduce the risk of flooding in the community . The work is carried out by Cit y Administration's Natural Resources Program, the California Conservation Corps, and Publi c Works and Utilities department staff, assisted by the occasional herd of goats . Throughout th e year staff thins vegetation, removes blockages, monitors various locations, completes CI P projects for flood protection and, through Measure Y funding augmentation, cleans storm drai n systems . It is important to note that even with all of the preparation work that is done each year, there are some fundamental creek capacity issues in the City . Due to these issues, flooding cannot b e prevented in the event of a major storm . San Luis Obispo Creek as it approaches the Downtow n has the approximate capacity to convey a 17-year storm event . Capacity downstream is even less , and through the Mid-Higuera reach, it is closer to a 10-year storm event . This illustrates that storm events, and their associated rainfall amounts, may result in flooding, even though Cit y staff has undertaken winter preparation activities and completed CIP projects in advance . 2011-12 Drainage System Winterizatio n 1 . Rock Guard s Throughout the City there are about 15 rock guards . These "pipe grate" structures are typicall y placed near the entrance of a culvert that accepts drainage from the steeply sloped hills aroun d town. Their purpose is to prevent large material and debris (rocks, branches, etc .) from enterin g the culvert, becoming lodged in place, and creating a storm water back-up that cannot be easil y removed . The Street Maintenance staff checked and cleared all rock guards at the end o f summer . SS2-1 2011-12 Winter Weather Preparation Page 2 Rock Guar d The Street Maintenance staff has also checked all historically troublesome drain inlets an d culverts to make sure they are clear of debris . Street Maintenance staff has worked closely with staff from the City's Natural Resource progra m and the California Conservation Corps (CCC) in providing drop boxes for creek debris as it i s removed from the channels . 2 .Creek Work The creek winterization program focuses on (1) the "usual suspects", areas that are known to b e problematic every year or almost every year ; primarily the lower reaches of San Luis Obisp o Creek inside the City limits, and Prefumo Creek between Los Osos Valley Road and th e confluence with San Luis Obispo Creek near Highway 101 ; and (2) problems identified by Cit y staff or called in by citizens in the summer and early fall months . This year staff contracted wit h the CCC and several private contractors to undertake this effort . This included the usual clearance of the flood bypass on lower San Luis Obispo Creek between Prado Road and Lo s Osos Valley Road, and several other problem locations such as the Elks Lodge and Haywar d Lumber properties . It also included a number of clearing projects on the tributary creek s including Old Garden Creek at Broad Street, Stenner Creek at Murray and Broad, Islay Creek i n the Edna-Islay area, and Laurel and Acacia Creeks near Orcutt Road (this is the site of som e recent correspondence between residents at the Laurel Creek development, City staff, an d Council members). It is important to note that the City's winterization efforts include th e cleanup and removal of significant amounts of garbage and litter left at transient campsites . The rule of thumb in the City's stormwater management work along the creeks is to maintai n shade over the water to protect and preserve habitat, and use floodways whenever possible . Hence the strong efforts at the major floodway at the Water Reclamation Facility, which onl y carries water during storm events and allows the City to keep clearing activities in San Lui s Obispo Creek at that location to a minimum . Staff carefully considers the effect of pruning and SS2-2 2011-12 Winter Weather Preparation Page 3 removal along the active waterways with an eye toward keeping as much shade over the creek a s possible while maintaining flow capacity . It is a constant balancing act . 3.Multi-Agency, Multi-Department Efforts to Minimize the Impacts of Homeles s Encampments on the Creeks City departments, including Administration, Parks and Recreation, and Police have bee n collaborating with other agencies at the County and State level, as well as private landowners, t o address the issue of homeless camps in creek areas and the problems resulting from such camps . These problems include, but are not limited to, accumulations of garbage and litter, damage t o riparian vegetation, and lack of sanitation . Several areas have been cleared of camps and wer e cleaned up, but as the Council is aware, this issue does not simply go away ; instead it i s transferred to other sites either in town or just outside of it . Nevertheless, staff continues t o attempt to remove the camps where possible : this year the Laurel Creek and Acacia Creek areas and areas along San Luis Obispo Creek have been the focus of such efforts . The hope is that , once areas have been properly restored, local property owners will take over the effort and kee p their properties free from new encampments . 4.Stormdrain Cleaning . As part of the City's enhanced Storm Water program, scheduled maintenance cleaning of the storm drain system is routinely done . This work ensures the drainage inlets are open to wate r flow to reduce flooding potential and at the same time prevents debris from entering into th e creeks and storm drain infrastructure system . Wastewater Collection staff has developed a comprehensive maintenance program utilizing th e Hansen Infrastructure Management System (IMS) data base . Staff has continued to work wit h the Geographical Information System (GIS) division to develop and update the storm drai n maps . The Hansen data base integrates with the GIS system to assist staff in the field t o electronically locate and manage storm drain assets and IMS information . For efficiency an d historical information staff accesses maintenance records and GIS information via a mobil e wireless laptop computer to create and complete work order information . The storm drain system is divided into nine are a maintenance basins that coincide with the Pavemen t Management Plan Areas including the Downtow n basin . Throughout the system, storm inlets, sumps, an d catch Basins are cleaned annually . The Downtow n basin is scheduled and cleaned starting in September o f every year and prior to the rainy season . Storm pipe s are also identified to be cleaned and inspected on a three-year cycle . In preparing for 2011-12 winte r weather, staff has cleaned 1,609 storm inlets, inspecte d 529 segments of storm pipe and removed 180 tons o f debris . Stormdrain Cleaning Truck SS2-3 2011-12 Winter Weather Preparation Page 4 5 . Flood Protectio n By means of the Downtown Association newsletter, staff reminds businesses annually of th e need to prepare for winter weather . Specifically they are reminded to clear roof gutters and to locate flood gates so they are ready and accessible . Much of the Downtown core is in the 100 - year flood plain and as such, major remodeling and new construction is required to raise the floo r elevation or protect the property with flood gates . Flood gates typically consist of boards of som e sort which are fixed in front of the doors to reduce flood water intrusion . In the event of hig h water, the businesses or property owners are responsible to install these gates to protect thei r property . For liability reasons, the City does not tell businesses when they need to do this ; however, during severe weather, the City does release ongoing updates on the potential for risin g waters . City staff monitors weather reports, County stream gauges at certain creek locations, an d has observers in the field that report on the situation to the Department Operations Center at th e City Corp Yard . Property owners in high risk flood zones carry flood insurance through a federal insuranc e program . The rates are variable depending upon a number of considerations relating to reduce d flood risk . This year the City improved its Community Rating System rating for this insurance . This translates to an additional 5% discount on flood insurance premiums, for up to a total 15 % reduction for property owners in special flood zones . This higher rating was the result o f additional efforts by staff to improve our flood prevention program . These efforts included a flood warning program (a visual observation at key spots) and improved documentation of floo d response activities by the City . More credits are available now than in prior years for open spac e / flood zone beneficial uses . The City's GIS Division, Natural Resource Manager, and Cit y Biologist assisted with mapping and descriptions of beneficial use areas for this effort whic h assisted in gaining the higher rating . Adoption of new building codes by the Building Divisio n significantly improved the City's Building Code Effectiveness Grading System which also adde d points . The accumulation of all these efforts allowed the City to increase its score, resulting in a higher rating for the program . This effort translates into direct savings for property owners . Capital Improvement Project s During the last year silt removal was completed at Los Osos Valley Road at San Luis Creek an d Tank Farm at Hollyhock . These projects remove excess material from underneath the bridges to increase the volume of water that can flow through . Silt Removal — Los Osos Valley Road - Before Afte r The deck of a large culvert on Higuera Street at Exposition Creek, near the cemeteries, wa s replaced . SS2-4 2011-12 Winter Weather Preparation Page 5 One of the larger projects was the replacement of an existing creek bypass structure on Andrew s Creek near San Luis High School . Andrews Bypass and Rock Guard Structur e As part of the corrugated metal pipe (CMP) replacement effort, 340 feet of CMP was replaced i n Monterey Street, 85 feet of failed CMP was replaced in Higuera Street and reconnected to Sa n Luis Creek . 1000 feet of new or rehabilitated storm drain pipe has been installed in Highlan d and Cuesta drive to bypass a failed CMP system . Currently active in design are plans to remove and replace perforated CMP at the intersection o f Walnut and Osos with an anticipated construction date of February 2012 . This will alleviate a perpetually wet condition that creates potholes near the cross gutter . Additionally there are tw o larger CMP replacement projects currently in the design phase with anticipated constructio n dates of summer 2012 and 2013 that will remove CMP in poor condition and install a mor e robust type of pipe . Design work for repair of a culvert at Broad and Leff Street is about to star t with an anticipated construction timeframe of summer 2013 . Bank rehabilitation design wor k has just begun on San Luis Creek near Toro Street with an anticipated construction start o f summer 2013 . A culvert replacement project on Bullock Lane is currently under design with a n anticipated construction start of summer 2013 . Regulatory permitting is underway for silt removal projects in the Prefumo Creek Arm o f Laguna Lake, in Prefumo Creek below Laguna Lake, and San Luis Obispo Creek adjacent to th e Water Reclamation Facility . Actual removal is anticipated to occur in the summer of 2012 . Council may recall in July 2011, staff requested authorization to advertise these projects citin g all permits had been received excluding the Army Corps of Engineers (ACOE) authorization . The City advertised these projects for construction and at the same time solicited help fro m Congresswoman Lois Capps office for help to expedite ACOE approval process . Whil e Congresswoman Capps office did lend support to this effort, the ACOE permit still has not bee n obtained . Staff continues to pursue these necessary regulatory permits in order to complete thi s work in 2012 . SS2-5 2011-12 Winter Weather Preparation Page 6 Through an effort of the Zone 9 Flood Control and Water Conservation District, technical studie s for environmental work are complete for the Mid-Higuera creek widening . The City is now starting preparation of preliminary engineering that will be used in conjunction with the technica l studies for development of the project's environmental report . The project currently bein g studied is one that involves widening or overflow channels only on those properties owned b y the City . Project work has been funded by Zone 9 to this point . Miscellaneous Preparation s Sand has been delivered to the Corporation Yard, Laguna Lake Golf Course, Sinsheimer Par k and Santa Rosa Park and is available to the public in the event they experience localize d flooding . Community Service workers have been used to fill and palletized sandbags fo r emergency response and all chainsaws have been checked and repaired . Although the Winter Weather web page is available all year, staff places a reminder about the web site and the need to prepare for the upcoming wet season on Channel 20 . Radios have been delivered to respons e crews in the event cell phone service is lost . The Winter Weather preparedness web site covers a variety of topics including information o n safe travel during storms, reporting of downed power lines, protection of homes from flooding, and flood insurance . City staff also hosts a booth at Farmer's Market during December , distributing winter weather information and answering questions from visitors . FISCAL IMPACT The County Board of Supervisors has authorized approximately $180,000 of funding, throug h the Zone 9 Flood Control and Water Conservation District, for natural channel clearing, publi c outreach, and preliminary engineering for the Mid-Higuera project . While this funding has bee n available to the City for this type of work for a long time, it is discretionary on the part of th e County Board of Supervisors . With the exception of silt removal projects, the remainder of th e storm related Capital Improvement projects are funded with General Fund . The General Fun d projects for the next two years include the Toro Street Bank Stabilization – near Marsh Street , stormdrain pipe and inlet replacements – Citywide, and the Broad Street Culvert Repair – nea r Leff. Current and Future Measure Y funds dedicated for winter weather preparatio n Activity Type 2011-12 2012-13 Total Wastewater Collection Operators Operating $184,086 $184,086 $368,17 2 Storm Drain Replacement CIP $350,000 $350,000 $700,00 0 Culvert Repair CIP $35,000 $35,00 0 Toro Street Creek Bank CIP $35,000 $30,000 $65,00 0 Broad Street Bank CIP $35,000 $35,00 0 Total $35,000 $634,086 $1,203,17 2 Completed CIP Projects for winter weather preparation Project Cost Tank Farm & Los Osos Valley - Silt Removal $14,50 0 Higuera Culvert $185,800 SS2-6 2011-12 Winter Weather Preparation Page 7 Project Cos t Andrews Bypass $329,30 0 Monterey CMP Replacement $302,20 0 Higuera CMP Replacement $65,10 0 Highland CMP Replacement $346,00 0 Walnut at Osos CMP (project bidding)$62,500 Total $1,305,400 ATTACHMEN T Location Map t:tcounwl agenda repons'puouc works carzu i ww adminvu i i w nterprepnpt i i winterprep.docx ATTACHMEN T 0 0 .5 1 I I I I 2 Mile s I I I I ROCK GUARD SS2-8 STORM DRAI N REPLACEMENT i--CREEK BYPASS