Featured Image (above) – Foreground: Part of the hills surrounding Tassajara Valley that would be protected if T Parks is approved. Highland Ridge and Morgan Territory Regional Preserve are visible in the background. Image credit: George Phillips

The Area at Risk

Save Mount Diablo (SMD) has defended the Tassajara Valley (Valley) and surrounding hills for over two decades. This rural area, characterized by rolling grassland and the important Tassajara Creek riparian corridor, is an agricultural buffer between protected open spaces in every direction.

A Long Embattled History

The public’s first major victory here was stopping the massive ‘Tassajara Valley Owners Property Association’ project in the late 1990’s. Under the leadership of former Contra Costa County (County) Supervisors Donna Gerber and Joe Canciamilla, SMD, the Sierra Club, Greenbelt Alliance, and hundreds of residents helped stop thousands of units proposed in the 4,900-acre project.

Then in 2000, we worked together to tighten the County Urban Limit Line (ULL; a line beyond which urban-style development can’t occur) to place the Valley and other places outside the line, increasing their protection.

In 2004, when Contra Costa County’s Transportation Sales Tax “Measure C” came up for renewal as “Measure J”, activists including SMD successfully included a provision that the County and all cities adopt voter-approved ULLs. In 2006, County voters and every city including San Ramon once again approved an ULL with the Valley outside the line.

In 2007, the ‘New Farm’ project proposed to build 186 houses and a cemetery over 771 acres of the Valley. Developers proposed to do this by changing the definition of what “urban” development is. If people accepted that development beyond the ULL wasn’t “urban”, then it wouldn’t matter if it was on one side of the line or the other. Thanks to the work of SMD, concerned officials, Valley and nearby city residents, no one was fooled. So much resistance was generated that the developer would later table ‘New Farm’.

In 2010, we achieved a great victory in San Ramon against Measure W, which would have greatly expanded San Ramon’s ULL to include the Valley and allow housing subdivisions over the whole area. With the help of San Ramon residents, we crushed it with 72% of voters saying “no” to developing 1,600 acres of the Valley.

Besides massive housing projects, there’s also a cemetery proposed on 220 acres of the Valley. Creekside Memorial Cemetery would impact rare plant and animal species, as well as the Valley aquifer. The local community was so concerned that when SMD led a hike in the summer of 2014 against this project, about 500 people, including local ranchers, showed up to signal their opposition! The cemetery project has gone quiet for a few years, but it may come back soon.

Right Now

Currently, the same developer that proposed ‘New Farm’ has worked for years on a very different project, ‘Tassajara Parks’ (T Parks). In 2013, ‘New Farm’ was tabled and the developer began meeting with SMD, cities and other stakeholders to see if a compromise could be reached: he would get a return on his investment, and we could greatly benefit the public by dramatically reducing project impacts and threats to the ULL.

T Parks proposes two main things:

1) adjust the current ULL to move 30 acres inside the line and build 125 houses there next to Tassajara Hills Elementary School, and

2) protection of 710 acres (92% of all the land involved in the project) as open space, most of which would connect with existing Hidden Valley Open Space areas just east of San Ramon.

Above: Map of the proposed Tassajara Parks project site area (marked by translucent green with yellow boundary line), including existing protected open space (marked in solid green).

So What’s the Controversy?

Normally, we’d say that any project protecting 92% of the land is a no-brainer in terms of the massive conservation benefits to be gained. Even more in this case, since the land to be protected with T Parks connects with existing protected lands. Also, building on just 30 acres, as opposed to spreading houses over 771 acres of the Valley, is a huge difference.

However, The Valley is a water-short area, and residents are concerned about groundwater effects. The 30 acres where houses would be built are also just outside the current ULL. What if allowing this project to adjust the ULL encourages other projects around the County?

What We’re Considering

SMD doesn’t view T Parks in such alarming terms. First, the proposal is perfectly legal. Right now the ULL can be adjusted by 30 acres or less (changing it by more than 30 acres requires a vote of the people) with a 4/5th’s vote of the County Board of Supervisors if certain requirements are met.

Second, T Parks would not use groundwater. Water would be piped in like other typical urban developments. There is no evidence that removing 30 acres of surface area would significantly impact groundwater recharge potential for the thousands of acres in the Valley.

Third, the ULL can already be moved, and by much more than 30 acres. If a developer’s measure is proposed and wins a vote of the people (as happened in Pittsburg and Antioch in 2005), thousands of acres could be brought within the ULL instead of just 30.

Fourth, the 30 acres proposed for development is right next to an already developed area. The rest of the project site that would be protected covers a huge swath of the Valley that possesses higher conservation values than what would be developed. The open space which would be protected would create a “green wall” along this part of the ULL, making it more permanent.

Fifth, after decades of battle, this is a much better project than what has been proposed before and is a good way to get a powerful developer out of the Valley by allowing him to develop just 4% of the 771 acres he owns here. If T Parks fails, nothing guarantees that something much worse won’t follow, and possibly succeed.

Sixth, such a lopsided ratio of protection (710 acres) for development (30 acres) is a very positive precedent. Given the location of proposed open space in such high-quality habitat for rare species, next to existing protected areas, the potential conservation benefits of T Parks are immense.

Finally, the developer is also proposing to help the Valley by creating an Agricultural Enhancement Preserve (AEP), which would get various jurisdictions on the same page about the area’s future, by providing millions of dollars for additional preservation and agricultural enhancement.

No formal position yet.

SMD has not yet taken a formal position on the T Parks project itself, but we already support the AEP and the proposed conservation benefits.

We continue to work out details on the AEP and the proposed mitigation fund. We’ll keep you posted!