The Meaning of Hahamongna

The original settlers of the region were sometimes called the Hahamongna Indians. The word means "Flowing Waters, Fruitful Valley" in the native Tongva language.

Hahamongna News


Report on recent Hahamongna Advisory meeting





Mary Barrie


Friends of Hahamongna Blog


The following is a report on two items of interest which were discussed at the March 22 meeting of the Hahamongna Watershed Park Advisory Committee.

The first was the Hahamongna Basin Multi-use Project, a cooperative effort between the Los Angeles County Flood Control District, the City of Pasadena, and the Arroyo Seco Foundation. The project is one of 13 Greater Los Angeles Integrated Regional Water Management Plan projects submitted to the CA Department of Water Resources for possible Proposition 84 funding. Should funds be awarded, the grantee would be Los Angeles County Flood Control which would complete a Memo of Understanding (MOU) with the Arroyo Seco Foundation. The initial amount requested is $4,341,281 and the total project cost is estimated to be over $7 million.

According to the grant application, this project "will increase water supply, improve water quality, and improve ecosystem health..." Some of the project components include the removal of 250,000 cubic yards of accumulated sediment from the Hahamongna Basin and the use of this sediment to create 23 acres of open space outside the flood zone at the northern end of which the existing parking lot will be expanded south to accommodate 200 vehicles. Adjacent to the parking lot, the compacted fill will create a 4-acre level field to accommodate a future 2.4 acre multi-purpose field. (This sediment removal project is not the Los Angeles County Flood Control Post Station Fire Sediment Removal Project but rather an additional project to be completed after the County's project.)

Other project components in the Basin include raising the base elevation of the SCE power poles, restoring habitat, raising 3000 linear feet of the Perimeter Trail out of the area of frequent inundation, restoring Berkshire Creek, and widening an existing park road to allow for two way traffic.

Up in the Arroyo Seco Canyon, project components include replacing the intake dam with an inflatable dam, fish screens, habitat restoration, trail enhancements and the installation of a public restroom.

The staff presentation at the meeting emphasized that certain of the above components of the Hahamongna Basin Multi-use Project, such as the sediment removal to create the sports field and enlarged parking lot, would not be paid for by Prop 84 IRWMP funds. These projects such as the Sycamore Grove field and the Berkshire Creek restoration were identified as "Multi-benefit Projects." When questioned, staff stated that other funding sources for these projects had not yet been identified.

There followed a long and confusing discussion concerning future environmental documentation, the first of which was to be completed in June 2011 according to the grant application. Pasadena staff assured both Committee members and the public that this date was incorrect. There will be environmental impact reports done for the IRWMP-funded portion of the project, for the portion staff referred to as the "Multi-benefit Projects," and for the County Flood Control Post Station Fire Sediment Removal Project. How these environmental impact reports will be coordinated is unclear. Stay tuned for how to get involved when more information on this is made available.

If you are interested in learning more, take a look at the Prop 84 Implementation Grant Application which is available online. The work plan for the Hahamongna Basin Multi-use Plan is in Attachment 3. Work Plan 1 of 5. The link is

Staff also gave an update on the JPL east parking lot, all but 200 spaces of which is to become spreading basins. JPL is planning to move ahead with a $22 million parking structure on their own property. When this is built, the lab will no longer need the east lot parking in Hahamongna. Funding has not yet been approved by Congress, however.

The Advisory Committee passed a motion to recommend to the City Council that the Council urge JPL to plan its onsite parking garage so that the lab can also vacate the 214 space parking lot on the west side of Hahamongna (the lot immediately adjacent to the JPL campus). You may recall that the west side parking lot is the so-called "temporary" parking lot which was carved out of park open space in 1986 and which has always been slated to return to open space. The motion passed unanimously/

The next Hahamongna meeting will be held May 24, 2011. The March agenda item concerning the HWP Annex and Environmental Education Center Planning was held over until this meeting.