A drone view of floodwaters from the Sacramento River overtopping the Tisdale Weir in Sutter County, California. An atmospheric river storm dumped heavy rain and snow across Northern California. An atmospheric river storm dumped heavy rain and snow across Northern California. Photo taken March 1, 2019. Florence Low / California Department of Water Resources, FOR EDITORIAL USE ONLY

CA WATER COMMISSION: Update on the Central Valley Flood Protection Plan

A drone view of floodwaters from the Sacramento River overtopping the Tisdale Weir in Sutter County, California. March 1, 2019.
Photo by Florence Low / DWR

While considerable progress has been made to improve flood management in the Central Valley, the vast region still faces significant flood risk. Approximately 1 million Californians live and work in the floodplains of the Central Valley, with approximately $80 billion worth of infrastructure, buildings, homes, and prime agricultural land at risk. It has been estimated that California needs to spend at least $34 billion to upgrade dams, levees, and other flood management infrastructure.  Accomplishing these upgrades within 25 years would mean spending $1.4 billion per year—roughly twice the current level of investment.

One of the California Water Commission’s statutory responsibilities is to advocate for federal funding for flood control projects; however, the Commission has not been involved in the federal flood advocacy for some time.  The Commission’s draft strategic plan includes a goal of determining whether there is a need to reactivate this role.  At the December meeting of the California Water Commission, commissioners were briefed by Darren Suen, Principal Civil Engineer and Policy Advisor for the Central Valley Flood Protection Board, who gave an overview of the Board’s responsibilities and its role in obtaining federal funding for flood control projects.


Darren Suen began with the history of the Central Valley Flood Protection Board.  During the Gold Rush period, people were settling in the valley and communities were forming.  Around 1850, there was a major flood.  After that, people were building levees to protect their own lands, but a battle of levees ensued where in order to protect their own lands, they would breach the levees of the neighbor’s lands, a story told in the book, Battling the Inland Sea.

Around 1905, Major Dabny of the Army Corps of Engineers led an independent commission to decide a plan of action.  There were a lot of debates on how to address the issue; some folks wanted to have places where water could come out of the channel, but ultimately the Commission went forward with a plan to try to keep all the water within the channel.

Nobody at the time thought that more than 250,000 cfs would come down the Sacramento River system; they didn’t have any data to actually validate that but that was their belief.  During the same year, river gauges were installed in the system, and luckily they had not moved forward with the actual construction of that system because in 1907 and 1909, there were massive floods.  What they realized after the river gauges were installed that 600,000 cfs had come through that system, which made them realize the plan wouldn’t work and would have to be revamped.

Next, Major Jackson with the Army Corps of Engineers developed the plan which included a series of flood bypasses and weirs in addition to the river system.  The entire flood system was meant to continue to allow the reclamation of lands for farming, but also to improve navigation within the channels, and by bringing those levees a little closer together, they would increase the velocity and then flush out the debris from the hydraulic mining that was occurring for the Gold Rush era.

The Jackson Plan was that authorized in 1910 and it was the first federal authorization of the State Plan of Flood Control.  In 1911, the Reclamation Board was formed, which was the predecessor to the Central Valley Flood Protection Board.

In the mid-20th century, construction was completed on Shasta Dam and Oroville Dam.  There have been significant flood events since then, most notably in 1986, 1997, and the recent storms in February of 2017.  The storms in 1997 generated estimates of 1 million cfs coming through the system.

The overall message here is that from the very beginning in the 1850s and early 1900s, the estimation of these peak flows continued to be underestimated, so it’s why all of us working in flood management need to be vigilant in continuing to monitor the system and improve upon this system,” Mr. Suen said.

The mission of the Central Valley Flood Protection Board is to reduce the risk of catastrophic flooding in this region.  On the map, the red lines are the boundaries of the Central Valley Flood Protection Board which is the tributaries and the Sacramento-San Joaquin River systems.  The land shown in green is the Sacramento-San Joaquin Drainage District or SSJDD, which was originally formed to leverage capital to construct the earliest levees.

It’s a unique function that this board has,” he said.  “Very few state entities have land management authority and the Board is one of them.”


The seven voting members of the Board are Governor-appointed and Senate confirmed. Board members are chosen for their expertise in the areas of flood control, engineering, water law, hydrology, and environmental stewardship in order to provide a knowledgeable review and discussion of flood management issues brought before them.  There are also two ex-officio members (non-voting) from the legislature who are the chairs of the Assembly Water, Parks and Wildlife Committee and the Senate Natural Resources and Water Committee.  The board meets on the fourth Friday of every month.  There is a coordinating committee that meets monthly to work with state and federal partners and stakeholder groups to talk about issues in a more engaging fashion.  They also conduct workshops as needed on any topic that might be pertinent at that time.

Water Code section 8710 speaks to the broadness of the authority of the Board, stating that the Board has authority over every plan of reclamation, flood control, drainage, improvement, including the construction, enlargement, or alteration of any levee in the Sacramento or San Joaquin Rivers or any of their tributaries.  The Board oversees 1600 miles of State Plan of Flood Control levees and 210,000 acres over 19 counties in the Sacramento-San Joaquin Drainage District.

The Board’s programs are mostly regulatory in nature.

In terms of federal advocacy, the Board is involved with US Army Corps of Engineers Section 408 applications.

With Section 408, the Army Corps recognized that sometimes there needed to be private projects in the system so it allowed for a process that non-federal entities projects could apply and be reviewed by the Army Corps of Engineers in order to proceed or go to construction.  The applicants need to demonstrate it’s not injurious to the system and that it doesn’t impair the function of that system.

Mr. Suen explained that the Board as the non-federal sponsor went with the original authorization of the plan and remains the non-federal sponsor for the Corps.  As such, it coordinates those Section 408 applications and signs on to project partnership agreements with the Corps any time the state and other local flood agencies want to enter into an agreement to do capital projects.


The Central Valley Flood Protection Act of 2008 (SB-5) renamed the Reclamation Board to the Central Valley Flood Protection Board.  In that legislation was an aspiration to achieve a 200-year level protection for the urban areas in the system and a mandate for DWR to develop the Central Valley Flood Protection Plan and the Board to adopt it.  The plan is to be updated every 5 years.  The first Central Valley Flood Protection Plan was adopted in 2012 and updated in 2017.

For the 2017 update, the Board did a lot of stakeholder outreach and engagement on both the Sacramento and San Joaquin river systems.  They formed six regional groups, three on the Sacramento River system and three on the San Joaquin system, who then developed regional flood management plans.

Each one recognized they had their own individual challenges so having them all provide input into the update made the plan a much better plan than the original from 2012,” said Mr. Suen.  “There was a lot of praise for the plan by the stakeholder groups and even by professional organizations as well.”

The 2017 update of the Central Valley Flood Protection Plan included an update to the investment strategy to fund the enhancements to the flood system to protect high risk communities and to also achieve the State Plan of Flood Control design capacity which it was originally designed for.

Back in the early 1900s when that plan was first authorized, there was no CEQA, no Endangered Species Act, and no habitat requirements at the time, so we’re asking a lot more of the flood system than what it was originally designed for, so how do we balance that,” he said.  “The plan includes a conservation strategy which is a science based approach to insert ecosystem functions into flood projects, so again, getting back to the multi-benefit type of mindset.  I think this plan did a good job in highlighting that.”

By statute, the plan must be updated every five years, so the 2022 update is just around the corner.  Mr. Suen said that they are partnering with DWR with the new Division of Multi-benefit Initiatives and working to develop a budget and a scope for what the next update will look like in 2022.

The Central Valley Flood Protection Plan focuses on eight policy issues that are needed to be addressed for future flood management initiatives:

Land use and floodplain management:  This can be described as keeping people away from water.  “For example, we don’t necessarily control land use authority but what can we do to better educate local governments in how they are planning out their communities to minimize flood risk,” he said.

Residual risk management: This is keeping water away from people, such as emergency response.

Hydraulic and ecosystem baselining:  This is critical when large infrastructure projects that years even decades to implement in its entirety are under consideration.

Operations and maintenance:  Taking care of what we have.  A lot of levees, weirs, bypasses, and pumps were built over 100 years ago and we need to maintain them.

Developing multi-benefit projects

Effective governance and coordination of federal agencies can be lumped together into how do we all work together.  “When it comes to flood management, it’s all about a team effort so we all have our respective roles, responsibilities, and authorities, but everybody knows that in order to get anything done, we’ve got to work across those,” said Mr. Suen.

Finance: How are we going to pay for it, which is always the question, he said.


With respect to implementing the plan, funding is an issue, so they are conducting a feasibility study to study the possibility of repurposing the Sacramento San Joaquin Drainage District, originally formed decades ago to fund capital improvements, to be a source of funds for operations and maintenance of the system.

Colusa Weir releases overflow waters of the Sacramento River into the Butte Basin in Colusa County, March 2019.
Photo by Zack Cunningham / DWR

Mr. Suen acknowledged there’s a lot to that conversation.  Some local communities have already done Prop 218 assessments so what would that mean for them?  What is the value of the land to be protected and does the economics make it worthwhile? Is there support in the legislature to repurpose this assessment district, different from the drainage district itself which is a land entity?

There’s a lot to get into and but we were directed by the legislature to find ways to be a relief to the general fund, so we hope that this can be one avenue,” he said.  “So stay tuned.  It’s just getting underway.”

The second important point is the Yolo Bypass-Cache Slough partnership.  Mr. Suen likened the Yolo Bypass to a single pallet that a lot of artists want to participate in and there are a lot of opportunities to utilize the flood bypasses to benefit the ecosystem while also enhancing flood management.

However, there are difficulties with looking at things incrementally, he pointed out.  “If I lower the hydraulic baseline by making the system wider, but then come in later with a habitat restoration project that increases roughness and therefore raises the hydraulic baseline, looking at those things incrementally, the former one is ok but the other one is not okay,” he said.  “But if we’re able to develop a system where we can look at all of it in its entirety and have a baseline that is taking into account these different projects over time … If we just look at it incrementally, it will be difficult for us to get through that 408 process, but if we’re able to look at things in a programmatic way and make consistency determinations for that programmatic permit, than we can streamline things faster and we can accomplish a lot more.”

The partnership can address a lot of concepts in the Central Valley Flood Protection Plan by bringing federal, state, and local agencies together with stakeholders who are affected by agriculture and property rights to look at things holistically which will hopefully make it possible to do a lot more and faster, he said.

Floodwaters from the Sacramento River overtop the Tisdale Weir in Sutter County, March 2019.
Photo by Florence Low / DWR

Mr. Suen then closed with some comments about federal funding.  Once federal earmarks were eliminated, it changed the whole dynamic for federal advocacy.

Today, a lot of the funding is driven by the staff at the Army Corps of Engineers and the needs of the local, meaning non-federal and also non-state entities – those agencies are implementing projects, such as the Sacramento Flood Control Agency, what can they actually accomplish during a budget year.   The state helps coordinate that and provides its input to the Army Corps, but the decision itself is often recommended up through the Army Corps, so we don’t really have much of a role in asking for money like it used to be.  They are trying to bring earmarks back, we understand, so there’s conversations about that, but I don’t have any significant news on that.”

Vice Chair Carol Baker asks about the governance, particularly as it relates to operations and maintenance.

Mr. Suen replied that when the system was developed, the federal government basically had the state (or the Board) take on the role to ensure that the facilities are maintained properly.  The Board then passed the role on to local agencies and required them to keep it maintained or the Board would enforce upon that as well.  In many cases, these local areas are farmers who hire professionals for certain things, but a lot of times, they are just trying to take care of their own lands.

Sometimes it gets to the point where they are not able to do it, then they come to the state and ask to become a maintenance area.  This is not done through the board; it is done through the Department of Water Resources Division of Flood Management Flood Maintenance Office.  They come in and assess fees in order to raise money, but it then becomes the state’s responsibility.

Governance wise, ultimately the Board is responsible for State Plan of Flood Control facilities that we the state gave the assurance to the federal government that we would take care of,” he said.


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