Pilarcitos Creek facts for kids

Pilarcitos Creek is a stream in San Mateo County, California. It flows about 13.5 miles (21.7 km) from the Santa Cruz Mountains to the Pacific Ocean. The name "Pilarcitos" means "little pillars" in Spanish. It flows through Pilarcitos Canyon and ends at Half Moon Bay State Beach.

This area, called the Pilarcitos Creek watershed, is very important. It provides clean drinking water for many people. It also supports farming and tourism. However, there is a growing need for water from different groups. These include farms, homes, businesses, and the environment itself.

History of Pilarcitos Creek

Early Explorers and Names

The Portolá expedition camped by the creek on October 28, 1769. Father Juan Crespí named it Arroyo de San Simon y San Judas. This was to honor the Catholic Feast day for the Apostles Simon and Jude. Later, in 1836, the name Arroyo de los Pilarcitos was used in land papers. This means "creek of the little pillar-like rocks."

Working Together for the Creek

People and groups have been working together since 1992 to protect the creek. This started after two pollution events happened. Money from these events helped create a fund for restoration work. This led to the 1996 Pilarcitos Creek Restoration Plan.

The Pilarcitos Creek Advisory Committee (PCAC) was formed. It is a group of citizens who give advice on the plan. They also guide the San Mateo County Resource Conservation District (RCD).

In 2005, many local and regional groups met with almost 200 community members. They talked about ways to manage the creek's water. The goal was to balance water use for everyone.

In 2007, different groups formed the Pilarcitos Creek Restoration Workgroup. This group helps create a plan to manage the watershed. They want to find solutions that help the environment, public health, water supply, and the economy.

About the Pilarcitos Creek Watershed

Where the Creek Flows

The Pilarcitos Creek watershed covers about 30 square miles (78 km²). The creek starts at 1,430 feet (436 meters) high. It begins on the south side of Whiting Ridge, near Montara Mountain. It flows southeast to Pilarcitos Lake Reservoir. There, Spring Valley Creek joins it.

Pilarcitos Dam was built in 1864. Two miles downstream, Stone Dam was built in 1871. Further down, Albert Gulch joins Pilarcitos Creek near Highway 92. Albert Gulch is named after the Albrecht family, who lived there for many years.

From there, Pilarcitos Creek turns southwest for about 3 miles (4.8 km) to Half Moon Bay. Along the way, it is joined by several smaller creeks. These include Nuff Creek, Corinda Los Trancos Creek, and Apanolio Creek from the right. From the left, Madonna Creek and Arroyo León join it. Finally, it flows west-northwest for 3.2 miles (5.1 km) to enter Half Moon Bay and the Pacific Ocean at Elmar Beach. The highest water flow recorded was 4,750 cubic feet per second (134.5 m³/s).

Water Supply for Cities

As early as 1860, a large project was built to bring water from Pilarcitos Creek to San Francisco. Two tunnels carry water from Pilarcitos Lake Reservoir and Stone Dam Reservoir. Today, Pilarcitos Creek still supplies water to San Francisco and the Peninsula. This water goes through the Crystal Springs Reservoir. It is also the main source of drinking water for Half Moon Bay and nearby coastal areas.

The city of Half Moon Bay controls land use in the lower parts of the creek. San Mateo County controls land use in the upper parts. Both follow California's Local Coastal Program rules.

Health of the Watershed

Animals and Plants

The Pilarcitos Creek watershed is home to many different plants and animals. This includes anadromous steelhead trout (Oncorhynchus mykiss). These fish are listed as "threatened" by the government. This means they are at risk of disappearing.

Over time, human activities have harmed the watershed. This has threatened native plants and animals, including the steelhead. Also, more people mean more demand for water. This leaves less water flowing in the streams for nature.

Main Challenges for the Creek

In 2008, experts looked at the watershed's condition. They found several key issues:

• Water Flow: There isn't enough water flowing in the streams during dry summer and fall months. This affects fish and other water creatures.
• Ecosystem Health: Other problems include things like fish not being able to move freely. Also, there are issues with places for fish to live, soil erosion, and plant life along the creek. Invasive species, which are plants or animals not native to the area, also cause problems.
• Community Issues: Getting the community involved is important. Landowners have concerns, and there are issues with beach quality and old landfills.

Sometimes, levels of Fecal coliform bacteria at the creek's mouth are too high. This means the water does not meet California's water quality standards.

Biodiversity and Habitat

The Pilarcitos Creek watershed has a lot of different living things. It is a known habitat for the endangered San Francisco garter snake. Along the creek, you can find arroyo willow (Salix lasiolepis) and red alder (Alnus rubra) trees. In the surrounding areas, there are coast Douglas fir forests.

Integrated Management Plan

Goals for a Healthy Creek

The Integrated Watershed Management Plan (IWMP) suggests projects to help the creek. Its goal is to find balanced ways to manage the Pilarcitos Creek watershed. This means meeting the needs of the environment, public health, water supply, and the economy.

The plan focuses on six main goals:

• Protect and help steelhead trout and other native water animals and plants recover.
• Increase streamflows while still providing enough water for people.
• Manage the creek banks to reduce soil erosion and flood risks.
• Increase the number of native plants along the creek.
• Keep the water quality good.
• Encourage people and groups to work together.

For each goal, there are specific steps to follow. These goals and steps were agreed upon by the workgroup and the public. They form the basis for how the plan will be put into action.

Pilarcitos Restoration Workgroup

The Pilarcitos Restoration Workgroup continues to lead the efforts to put the IWMP into action. This group works together to find balanced solutions for managing the watershed.

Current members of the Workgroup include:

• California Department of Fish and Wildlife
• California State Parks
• City of Half Moon Bay
• Coastside County Water District
• Coastside Land Trust
• Committee for Green Foothills
• Midpeninsula Regional Open Space District
• National Marine Fisheries Service
• Peninsula Open Space Trust
• Pilarcitos Creek Advisory Committee
• San Francisco Public Utilities Commission
• San Mateo County
• San Mateo County Farm Bureau
• San Mateo County Resource Conservation District
• Sewer Authority Mid-Coastside
• Surfrider Foundation - San Mateo Chapter

The San Mateo County Resource Conservation District (RCD) organizes the Workgroup meetings.