Pasadena’s Public Works Updates City’s Municipal Services Committee about Devil’s Gate Project on Tuesday

The City of Pasadena’s Department of Public Works will present an update on Los Angeles County’s sediment removal project at Devil’s Gate, currently on hold after a judge ruled in March that the project’s Final Environment Impact Report (FEIR) does not ensure effective mitigation measures that would prevent damage to the natural habitat at the Hahamongna watershed area.

Public Works will present the update Tuesday in the Municipal Services Committee meeting which starts at 4 p.m. at the City Council Chamber at City Hall.

In the ruling last March, Judge James C. Chalfant of the Los Angeles Superior Court said the FEIR must be set aside until the Los Angeles County Flood Control District is able to say for certain “that mitigation would be effective,” and has been able to newly analyze any proposed habitat mitigation. The judge also sought that the district perform a feasibility analysis for the use of model year 2010 or later trucks when it starts digging sediment from Devil’s Gate.

As approved by the County Board of Supervisors in 2014, the LA Flood Control District has chosen Alternative 3, Configuration D, Option 2 of the Big Dig project, which entails removal of 2.4 million cubic yards of sediment from a little over 70 acres of the reservoir, and managing the remaining sediment in over 52 acres.

The project approval remains even after Judge Chalfant’s decision, only that the District needs to improve the FEIR by providing substantial evidence to support its target one-is-to-one ratio in its mitigation measures and the conclusion of less than significant impact to resources; confirming that the biological resource mitigations will be applied the Devil’s gate Water Conservation Project, should it go forward; and modifying a mitigation measure to mandate that all sediment removal trucks meet EPA emission standards for Model Year 2010 or later.

The City of Pasadena was given an opportunity to review and comment only on the recirculated portions of the FEIR after Chalfant’s decision, although all prior comments and responses remain. According to a preliminary report by the Public Works Department, City comments were submitted to the County in September. In addition to the comments, the City re-stated its position in support of a City Working Group’s alternative to the Big Dig project.

The City comments include its continued insistence that the District provide substantial evidence to support the 1:1 mitigation ratio and the conclusion of a less than significant impact to biological resources in the watershed area. It also said a “corrective re-grading” of the dig area that the District mentioned in the FEIR is not well defined; the City is requesting that the District work collaboratively with the City if this measure is necessary.

The City also maintained that the project’s “closing trails or installing barriers” measure needs specific criteria regarding when it would be implemented. It said all identified trails must be outside of the mitigation areas and therefore should not be closed during the dig; if there should be any closure, the City said it must be allowed to work collaboratively with LACFCD in advance.

The City also said the project’s tree replacement strategy is not clearly defined in the FEIR. The City is requesting likewise that the District work with the City to determine suitable tree planting locations.

The other comments by the City relate to seeking a clear mechanism to ensure application of mitigations measures, and a separate mitigation measure that specifically requires all other biological mitigation measures be applied.

The County is expected to respond to the City’s comments by early November. Prior to this, the County has scheduled at least three community meetings within this week to gather public input.

Before the end of November, the County must return to court to report on its compliance with the March ruling.

In the meantime, the Los Angeles County Department of Public Works conducts annual maintenance work at Devil’s Gate just to it retains its flood risk management function for the communities along the Arroyo Seco including Pasadena.

Since 2011, the County has been removing sediment, dead tree branches and vegetation from area immediately in front of the dam, hauling the sediment to Johnson Field for temporary storage and the green waste to the Scholl Canyon Landfill. It does this during the fall months typically in a four to six week duration.

The interim measure uses a maximum of 10 trucks per day using Windsor Avenue and a biologist is always on site to oversee all work activity. Trails within the reservoir remain open during these “little digs,” except for brief closures or detours with advance notice to users.

The Public Works Department says work for this upcoming storm season has been completed.

Between 2011 and 2017, the County has removed 48,000 cubic yards out of the dam through this interim maintenance measure, the Department said.