Los Altos


The City of Los Altos is a mid-sized community in western Santa Clara County. Home to an estimated 27,693 residents, Los Altos is predominantly residential, with commercial areas limited to downtown and in office parks along the main roads. The city has retained characteristics of its former rural nature through elements such as large minimum lot size, few sidewalks and minimal street lighting, as well as a historic orchard in the town center.

The Santa Clara Valley Water District partners closely with the City of Los Altos, as well as local organizations and businesses, to ensure a reliable supply of water for a range of residential and commercial uses.

Shared Responsibilities

Most policies guiding development and use of resources in Los Altos are contained in the City's General Plan. The City also adopted Resolution 07-03 on Feb. 13, 2007 for water resources protection. Its Environmental Commission has been working on Watershedshed Stewardship Education and Outreach since Dec. 2011.

With the understanding that their roles and responsibilities often intersect, the District and the City work together on many key community interests. Major efforts have included:

  • Requiring new development to incorporate BMPs and water conservation devices.
  • Reducing imperviousness by requiring 50% pervious area for front yards, allowing for underground parking and limiting use of paved sidewalks.
  • Including tree protection regulations in the City’s Municipal Code.
  • Maximizing on-site infiltration of storm water runoff.
  • Prohibiting development in floodways.
  • Preserving natural resources along creekbeds.
  • Regulating discharge into creeks.

Looking forward, further collaboration or partnership will facilitate sustainable development in the region, particularly in the following areas:

When evaluating land use decisions:

  • Assess and plan for changes in water demand and storm water management, especially taking into account how urbanization affects the water cycle.
  • Decrease the demand for water.
  • Expand water use efficiency in existing and new development.
  • Actively pursue and facilitate the use of recycled water.
  • Protect and expand local water supplies.
  • Protect groundwater basins and source water protection zones.
  • Reduce flood risk.
    • Site new construction to assure stable stream channels and minimize flood risk.
    • Require that new construction in flood prone areas be built to flood safe standards.
  • Protect natural stream functions.
    • Restore fisheries, riparian habitat, and wetland areas.
    • Explore opportunities for increased creek-side trails and open space.

During operations of existing facilities or services:

  • Manage local storm drainage systems with stream capacity to contain floodwaters.
  • Support measures to reduce the exposure to flood risk.
  • Support measures to enhance flood preparedness and knowledge of risk exposure.
  • Prepare critical facilities for operations during flood events or prolonged draught.
  • Reduce pollutants entering streams.

When planning or working around creeks:


The interactive map below shows the location of Los Altos and illustrates some of the city's key features, such as major creeks, flood zones and groundwater subbasins.

To view key features, choose a layer from the "Select a layer to display" menu on the map below. You can select multiple layers to view at one time; if you wish to turn off a layer, select it again from the menu. Individual layers contain specific data that you can access by clicking on the layer itself.





Key Water Resources Features

The City of Los Altos transects the Adobe, Permanente and Stevens Creek watersheds. The Stevens Creek reservoir is the primary reservoir in the area. Four creeks flow through Los Altos.

Water Supply

Los Altos' drinking water is supplied by California Water Service Company. The City's General Plan includes policies and implementation programs that address water quality and water supply, and promote water conservation. The City of Los Altos General Plan Implementation Program outlines requirements implemented to improve surface water quality. The Plan does not have any policies or implementation programs related to groundwater protection.

Flood Protection

Portions of the four creeks flowing through Los Altos have been channelized to increase the capacity of the creeks to reduce flooding and to permit development of the flood plain. Further channelization is not recommended for any of the creeks in Los Altos because of the conflict with preservation of natural resources. Adobe Creek is the most flood-prone of Los Altos creeks. The District has requested the City to require set-backs along the creek and to require property owners to dedicate an easement or fee title to the District. The city has emergency procedures for the evacuation and control of populated areas within the limits of inundation below dams.

Watershed Health

Los Altos General Plan policies support the preservation and enhancement of creks, floodplains, riparian corridors and buffer zones. Regulations in the City's Municipal Code outline the responsibilities of property owners regarding watercourse preservation, such as keeping creeks free of trash, litter and excessive vegetation.

Citywide Programs and Projects

The City and the District collaborate on projects to maintain the health of the watershed and water quality, establish natural flood protection and provide access to open space and trails. Recent projects include:


Related Plan Elements

The Related Plan Elements listed below identify some of the District strategies  applicable to the city. They provide the basis for cities to provide better management of key water resources features within their jurisdictions and to work more effectively with the District to address water resources managemenet issues.

Related Plan Elements

District Has Primary Jurisdiction
E- Prepare and implement a multi-year Capital Improvement Plan for flood protection projects. (P)
District Has Primary Jurisdiction
E- Identify existing stream conditions and stream characteristics and implement practical solutions where appropriate, to improve stream stability and its dynamic equilibrium. (P)
District Advocates
E- Provide technical advice and, if appropriate, work with municipalities to manage stormwater to address stream flooding and environmental benefits. (T)
District Advocates
E- Advocate flood conveyance capacity is maintained on non-district owned channels. (T)
District Collaborates
E- Assist municipalities and citizens when needed to lessen potential flood impacts. (C)
District Collaborates
E- Include municipal planners in regional or local flood management planning activities.
District Advocates
E- Promote community awareness about best practices to avoid or minimize exposure to flooding potential. (T)
District Advocates
E- Assist in the incorporation of flood-wise design features (e.g., minimize imperviousness, preserve natural drainage, rain harvesting and provide flood water detention) within the watershed. (T)
District Advocates
E- Advocate or support protection of stream functions from the negative impacts of development. (T)
District Advocates
E- Promote awareness of risks for developing in flood hazard areas. (T)
District Has Primary Jurisdiction
E- Balance the protection and restoration of sensitive fisheries and aquatic species, such as steelhead trout, with a reliable water supply. (P)
District Collaborates
E- Identify and incorporate stream rehabilitation measures into capital projects and operations to avoid, minimize and/or impacts to watersheds, streams and natural resources. (P and C)
District Advocates
E- Provide information on stormwater management and design of floodplains and channels. (T)
District Collaborates
E- Engage in habitat conservation planning.(P and C)
District Collaborates
E- Protect, enhance and restore riparian vegetation and in-stream and tidal habitat conditions conducive to healthy ecology, including diked historical bayland wetlands, or former salt ponds. (P and C)
District Collaborates
E- Protect, enhance, restore and/or create habitats for key species indicative of watershed health. (C)
District Advocates
E- Promote the preservation of ecological buffers. (T)
District Collaborates
E- Inspect and clean creeks from neighborhood litter and graffiti.(P and C)
District Has Primary Jurisdiction
E- Protect and preserve groundwater recharge areas.(P)
District Has Primary Jurisdiction
E- Improve water quality of listed impaired water bodies.(P and C)
District Collaborates
E- Work with other entities for planning, design, construction, maintenance, and operation of trails/open space amenities.