El Niño is back and forecasters are predicting its fall and winter impact to include “wetter-than-average” conditions in the southern portion of the country. While El Niño cannot be prevented, we can prepare for it by looking at our recent experiences from the 1997 and 1998 event.

Based on our prior experience in Northern California, we can expect landslides, widespread flooding, bridge and stream bank scour, lots of road washouts and culvert failures. In the four years since the last El Niño, we’re still reconstructing what was lost from that event.

Every local agency should have an “Emergency Preparedness Plan” to address storm damage preparation and identify the resources to respond.

Figure: NOAA Forecast, dated 9-12-2002

Preparation Planning

A viable plan is essential in the task of minimizing impact and maximizing response.

Minimize Impact

This can be accomplished through an effective and thorough monitoring and maintenance program. Severe storms can inundate drainage systems on their own, but if culverts, channels, and inlets are impaired, the effects will be much more severe. Potential upstream debris sources should be identified and abated if possible.

Review maintenance records to identify areas that have experienced problems in the past. Those areas have a high potential for future problems, particularly if the same repair strategy was used repeatedly and failed.

Maximize Response

The creation of an accessible list of resources is essential to maximizing response. It is important to predetermine where to acquire supplies, equipment and work crews required to repair these facilities. Also, request 24-hour contact numbers for everyone on the list. The resource list should include:

· Suppliers - rock, asphalt, geotextile fabrics, pipe materials, barricades, “Road Closed” signs, K-rail, etc.

· Equipment - excavators, pumps and other equipment available at local rental or maintenance yards

· Prequalified contractors and consultants

· Disposal sites - landslide repairs often call for mass excavation

In order to insure a rapid response, it is important to have preapproved repair strategies. There are multiple techniques and products that can be used to repair various failures. Knowledge of these strategies will improve response times and design solutions.

Be familiar with all the permits in your area and the requirements. Most regulatory agencies already have an emergency permit process in place. Make sure your emergency is their emergency.

Response Planning

The elements of the Response Plan includes: Assessment, Repair Strategy, Repair Implementation and Restoration.

Assessment

Once a major storm event has occurred, everyone needs to be aware of their roles and responsibilities. Most public agencies already have a command structure set up through a local Office of Emergency Services, which can be utilized for a storm damage response. The first responders for a storm event will most likely be the police and the public agency maintenance crews. The radio communication system used by most police and maintenance crews provides the most reliable means of transmitting the information from the field to the office.

Repair Strategy

Once the local area has been assessed and the most critical areas identified, a strategy for repairs can begin. For recommending the initial repair strategy the agency should use a multidisciplinary team comprised of its own experienced staff engineers with experienced civil, hydraulic, geotechnical, and structural engineer consultants. The best solutions are multidisciplinary, since most failures result from more than one simple cause.

Temporary or permanent strategies for slip-out repairs may involve techniques such as rock buttresses, steel sheet pile walls, cantilever retaining walls, gabion walls, reconstructing slope with engineered/drained fill, or even road closure if alternate routes are acceptable. The design team should be familiar with preapproved design strategies. Consider innovative strategies for recurring or potentially large-scale problems. Look at the big picture and see what is happening in the watershed as a whole.

When developing strategies on a site-by-site basis the team should consider the following factors, other than simply the engineering solution:

· Economics of long-term vs. short-term repair strategies. These include lifecycle costs, disruption from road closures and travel delays during repairs.

· Environmental Constraints. Just because it’s an emergency doesn’t mean the project is exempt from the law. Consider direct and indirect impacts, loss of native habitat, water quality (NPDES requirements), and permits.

· Traffic impact during construction. Staging of the work may require temporary signal systems with generators in remote locations.

Repair Implementation

The project implementation can be handled in several ways, using either maintenance crews or contractors to reconstruct the facilities depending on the severity and extent of the damages. Immediately following the event, contractors will most likely be utilized on a time and materials basis. The less critical sites and more highly engineered sites could be prepared for a competitive bid process.

· Agree on strategies to address community, agency and public needs for giving and receiving information during repair activities (e.g. delays, traffic control, sign packages, press releases). Consider using portable changeable message signs.

· Ensure environmental compliance throughout repair with on-site environmental monitoring.

· Consider time delays and configuration of traffic queues with one-way traffic control.

Restoration

Once the repair has been implemented at a site, whether temporary or permanent, it should be reviewed for compliance with local and state safety standards or restored to its prior condition.

For more information on storm damage repair strategies, please contact Randell Harrison or Cory Belden at:

Harrison Engineering

562 Little Lane

Pleasant Hill, CA 94523

(925) 691-0450

Randell Harrison managed a multidiscipline design team to deliver nearly $20 million in storm damage plans and specifications to construction within an eight-month period in 1997. He is the principal owner of Harrison Engineering, a civil engineering firm dedicated to providing, protecting and rehabilitating public infrastructure.

Cory Belden served as a project engineer on numerous storm damage projects following the 1997 El Niño storms. He is currently a project engineer at Harrison Engineering.