Flood Emergency Action Plans | Santa Clara Valley Water

These Flood and Severe Storm event Emergency Action Plans have been developed and public versions are available:

Lower Peninsula Watershed Emergency Action Plan (includes Permanente & Hale Creeks, San Francisquito Creek, and Palo Alto Flood Basin)
West Valley Watershed Emergency Action Plan (includes San Tomas Aquino Creek)
- San Tomas Aquino Creek Quick Guide
Coyote Watershed & Guadalupe Watershed
- Lower Penitencia Creek Watershed Emergency Action Plan
  - Lower Penitencia Creek Quick Guide
  - Berryessa Creek Quick Guide
- Joint Emergency Action Plan for Severe Storm and Flood Response in the City of San Jose (includes Coyote Creek, Guadalupe River, Upper Penitencia Creek, Ross Creek, Canoas Creek, Lower Silver Creek and Lake Cunningham):
  - Volume 1 – Base Plan and Attachments
  - Volume 2 – Appendices (Creek Specific)
Uvas-Llagas Watershed
- Uvas Creek Emergency Action Plan
  - Uvas Creek Quick Guide
- West Little Llagas Creek Emergency Action Plan
  - West Little Llagas Creek Quick Guide

Valley Water provides flood management services for Santa Clara County. During severe storm events and high flows in the flood prone creeks, Valley Water implements emergency actions to protect life, property, and the environment. To do this, Valley Water works closely with partner agencies and other stakeholders to ensure a coordinated approach during flood and severe storm emergency events.

To improve the response to potential or actual flooding events, Emergency Action Plans have been developed that provide guidance on how Valley Water will prepare and respond to severe storm and high flow events. The plans describe 5 basic steps taken in response to storms and flood events.

Event Detection
Condition Level Determination
Notification and Communications
Actions and Responsibilities
Termination and Follow-up

A key component of these plans is to create an easy-to-understand and easy-to-communicate classification system for setting a readiness level based on flood risk. Before and during events, the level of risk for flooding uses the system shown below:

PREPAREDNESS	This is the base stage of readiness that will be the typical condition throughout most of the year. An Emergency Management Organization (EMO) is not active at this level. It is defined as: Flood stage (Minor Flooding or greater) is not estimated within the next 72 hours or The measured stream depth is below 50% of the flood stage.
MONITORING	This condition is variable and requires more intense monitoring and a heightened level of alertness. An EMO may be minimally active to monitor for any developing flood concern. This condition is defined as: Flood stage may occur in 48 to 72 hours, or Measured stream depth is at 50% to 70% of flood stage, or For areas that are controlled purely by storm drain runoff (flashy systems), the stream depth is estimated to reach flood stage or near design stage within 24 hours.
WATCH	Flood level or a serious flood threat is expected to occur. An EMO may be activated at an appropriate level. This is generally defined as: Stream depth is estimated to reach flood stage or greater within 24 to 48 hours, or Measured stream depths are at 70% to 100% of flood stage, or For areas that are controlled purely by storm drain runoff (flashy systems), the stream depth is estimated to reach flood stage or greater than design stage within 6-12 hours.
WARNING	This is a more urgent situation with flooding imminent or occurring. The EMO is generally active. This level is generally defined as: Flood stage or greater is occurring or is estimated to occur within 24 hours, or For areas that are controlled purely by storm drain runoff (flashy systems), the stream depth is estimated to reach flood stage or greater within minutes/hours or is occurring.

With the risk of flooding classified, the urgency of an event can be communicated and actions planned. However for actions to be most appropriate to the event, it is important to also understand and communicate how severe the event may be and what areas may be affected.

Valley Water and the National Weather Service both provide this type of classification. Below are the flood severity descriptions used by both agencies:

Flood severity description color-coded table

With an event's risk and severity established, the responsible agencies can best coordinate to provide a comprehensive response specific to the event.