El Niño/Storm Center

Raining Day

What is El Niño?


El Niño is a tropical weather pattern that occurs roughly once every three to seven years. It is characterized by the above-average warming of the surface temperature of the waters in the eastern portion of the Pacific Ocean that results in extreme weather, such as drought or flooding. Forecasters predict Southern California can expect to see a wet winter as well as a marked increase in storms. In Coronado, rain event drainage is impeded by low elevations and competing tides in some areas of the City.  Flooding may appear to be caused by clogged storm lines; however, this is rarely the case.  Pre-rain event preparation, breaks in rain events and tide drops may be the only flood relief.   The City has been hard at work preparing for this winter’s forecasted rain activity.

Resident/Business Preparation

During a storm event, city resources may be taxed. Your early preparation is as critical as ours. The public is strongly encouraged to prepare for El Nino by performing many of the same activities the city has done.    

Public Preparation Activities:

  • Know the areas prone to flooding (see map); plan accordingly
  • Purchase/retrieve and store sand bags, tarps and other flood prevention building devices as appropriate
  • Repair roof leaks. Clean gutters, downspouts and area drains
  • Prune trees and remove loose leaf debris
  • Review your insurance policy for flood damage and update as necessary
  • Assemble an emergency kit (battery flash lights, blankets, clothes, food, water, small generator, radio, etc)
  • Update your emergency contact list, prepare a safe travel route, keep car fueled
  • Remind family members to stay out of the water during and immediately after rain events
  • Avoid parking near storm inlets

During a Rain Event:

  • Avoid areas subject to flooding (see map); do not enter areas barricaded
  • Construct sand bag barriers as necessary to divert water away from property
  • Keep pets inside
  • Do not enter beach or bay waters as they are most susceptible to runoff pollutants during and immediately following a rain event.  
  • Alert Public Services immediately if city trees or tree limbs fall or if flooding is reaching dangerous levels. Saturated soils weaken tree stability.  Monday – Thursday 7: 00 am – 4:30 p.m. and Friday to 3:30 pm (619) 522-7380; anytime thereafter call the Police Department at (619) 522-7350
  • A fallen private tree should be handled by the responsible owner. If an immediate danger to public safety, contact Public Services or the Police Department
  • Do not open sewer manholes to alleviate flooding. This may overwhelm the sanitary sewer system and cause a spill
  • Report downed power lines or broken gas lines immediately to 911
  • Monitor weather reports

After a Rain Event:

  • Use caution if power and gas is turned off. Prevent igniting fumes by using battery flashlights instead of candles or matches. Do not handle live electrical equipment in wet areas.
  • Stay out of waters until County officials remove advisory notices

City Preparation

In recognizing the possibility of flooding from El Niño, the City of Coronado is taking precautions in advance of the advancing rainy season and is reviewing and updating as needed its emergency response plan and existing flood control and storm drain infrastructure. The City’s plan addresses flood preparedness, a notification process, flood response, floodwater removal and a contingency strategy.

The emergency response plan includes input from the city’s police, fire, public services and engineering departments. It provides information to guide and assist the City, through policies and procedures, to efficiently deal with all aspects of a flood emergency, such as would occur during an El Niño event. City staff is working to define all areas at risk of flooding; clear existing storm drains; drill public safety personnel in shore-based swift water rescue; monitor the channels that may bring potential flooding; identify trigger points that would require particular actions; ensure there are sufficient sandbags available to residents prior to significant rain events and remind residents that they are available at the normal locations: First Street and Alameda Boulevard, Fourth Street and Alameda and at North Beach and Cays Park parking lot; review and test the city’s alert and warning system; prepare information for the public on potential areas susceptible to flooding and personal emergency preparedness measures; and hire additional short-term maintenance personnel, as needed.

This is what the City had done in its preparation activities:

  • Rain event training and disaster preparedness for key city employees
  • Posted to the city website an updated rain event map depicting areas prone to flooding during rain events and which are subject to tidal influence (see map below)
  • On-going storm drain system and outfall diversion cleaning
  • On-going pump station inspection and maintenance
  • Stocked city and public sand bag supply
  • Added the Cays Park parking lot to the public sand bag pick-up site list
  • Inventoried and performed equipment preventative maintenance used during rain activities (vacuum trucks, backhoes, dump trucks, chipper, generators, chainsaws and flood control signs)
  • Inspected all public facility roofs and cleaned gutters and downspouts. Secured additional roofing resources
  • Reviewed after-hour and on-call procedures with key city staff.
  • On-going construction site inspections, disseminating El Nino preparation fliers
  • Pruned trees
  • Construct beach berms as necessary

Rain Event Map 

Rain Event Map
 
City Infrastructure

In preparing for El Niño, it is important to understand what the City is dealing with regard to its storm drain system. For a small city, Coronado has a surprisingly complex system to handle and drain storm water. Due to relatively flat conditions and circumstances brought on by the former Spanish Bight that was filled in 70 years ago, Coronado is crisscrossed with storm drain lines that carry storm water to the bay and ocean and sanitary sewer lines that transport sewage for further treatment. For the most part, the storm drain lines work with gravity. Some, however, require pumps to help drain the water. Parker Pump Station is located on Coronado Avenue. It is an underground three-story building that houses pumps for storm drains as well as the sanitary sewer system. There are seven pumps for the storm drain system at Parker Pump Station of varying size. The smaller pumps are used to divert storm water to the sanitary sewer system.

During rain events, the larger pumps take surface and high ground water in the Country Club area and transport it to the North Beach Ocean Outfall. This is no small feat because before it was filled, there was a body of water called the Spanish Bight, which separated North Island from Coronado (see photo at right courtesy of: Coronado Historical Association). The waterway was 1½ football fields wide and the only connection was a 60-yard-wide strip of sand at high tide along the ocean side. This is important to note because that waterway now sits under the City’s Country Club area. Drainage problems abound in this area, which was filled in 1945 with structural fill, to allow for development above. The high ground water level, impacted by high tides and coupled with major rain events, regularly leads to flooding at the street level.

Once a week, the Public Services Division must activate the pumps using the smaller pumps for about two hours. In order to avoid odors from bacteria buildup and accumulation of contaminants. The City has other problem areas, mostly due to geography. When it rains in Coronado, there is flooding in a few predictable locations:

  • First Street from B Avenue to beyond A Avenue
  • Orange Avenue northbound and C Avenue from Fifth to Tenth streets
  • Glorietta Boulevard, Pomona Avenue and Tenth Street (Five Points) intersection
  • Alley between F and G avenues from Seventh Street to Tenth
  • Fourth Street from Alameda Boulevard to G Avenue
  • Country Club area, especially on Coronado Avenue from Acacia Way to Eight Street and on Eight from Balboa to Coronado avenues
  • State Route 75’s southbound exit to the Coronado Cays

City staff has identified three projects to address flooding issues in the Country Club area, including corrections to the area’s storm line inflow and infiltration; Pine and North Beach outfalls rehabilitation; and Parker Pump Station generator and upgrades. None will be completed in time for this year’s potential El Niño. However, these projects, estimated to cost up to $2.8 million, are in various stages of planning, environmental review and design, and are expected to be completed over the next 3 to 4 years. Each will do much to address the enormous amount of tidal influence, groundwater inundation in the Country Club area; provide more control to direct storm water; and reduce localized flooding.

Other flooding mitigation projects identified in the City’s Capital Improvements Program includ the Bandel Storm Pump Station Upgrades and storm drain improvements to Third, Fourth and Fifth streets and I Avenue, at a cost of nearly $2 million.

Resources

National Weather Service Forecast
County of San Diego Beach and Bay Status Reports  status reports
San Diego County Office of Emergency Services
San Diego Gas and Electric Power Outage Map
City of Coronado Facebook Page
City of Coronado Twitter Account

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