The Lafayette Reservoir Tower Was Always Too Tall for Its Dam

How tall should a tower be when the dam it was built for was never finished? At Lafayette Reservoir, the answer turned out to be 40 feet shorter than the one that stood there for almost a century. The roughly 100-year-old outlet tower, long treated as the symbol of a city incorporated in 1968, was built for a dam that was never completed at its planned height. Crews spent this summer cutting it down to match.

Anyone who walked the Lakeside Nature Trail this fall has seen what's left: a shorter concrete stem wrapped in scaffolding, without the little operating house and roof that gave it its shape. The silhouette Lafayette adopted came from a 1920s engineering setback. The retrofit keeps the look of the top and finally makes the tower fit its dam.

A tower built for a bigger lake

According to the East Bay Municipal Utility District's project page, the original plan called for a dam 33 feet taller than the one standing today and a reservoir nearly three times as large. During construction of the earth-fill embankment, the soil couldn't hold that height and the embankment began to move. Engineers lowered the dam. By then the outlet tower had already been built in 1929 to match the bigger design.

So the tower stood tall over a smaller lake for decades. It also does real work. It's the reservoir's spillway and outlet, connected to conduits that run under the dam.

The height became a problem after the Oroville spillway emergency led to stricter dam safety rules. EBMUD says seismic studies found the tower and its conduits could fail in a major earthquake, and the state Division of Safety of Dams, known as DSOD, required a retrofit. The fix EBMUD chose removes the extra height the dam never needed.

Lafayette pushed for another option

The city didn't accept the shorter tower quietly. A volunteer technical committee argued the tower could keep its height with modest mild-steel reinforcement to its upper half. The City of Lafayette's project timeline traces how that effort played out.

Katz's letter cited DSOD's deadline and said EBMUD had already spent more than $500,000 evaluating alternatives. It also described the planned replacement, a lightweight metal operating house designed to evoke the existing top of the tower. A March 2025 city staff report concluded that EBMUD considered the matter closed.

EBMUD's board awarded the construction contract on November 25, 2025, for $14,490,490.

Thirteen rings off the top

Work started in May 2026 with road widening, temporary boat ramp improvements, a barge and scaffolding. The operating house came off in early July. Lamorinda Weekly reported that crews used cranes and a barge to remove the roof and operating house, then saw-cut concrete rings about 3 feet tall from the stem.

EBMUD's August stakeholder update, posted on the Lafayette Chamber of Commerce reservoir page, counted 13 rings in total and set August 21 as the target for reaching the new height. Thirteen rings at roughly 3 feet each comes to the 40 feet the tower was always over.

The debris left by truck, using the Acalanes Road on-ramp to Highway 24 so it never passed through downtown.

What goes back on top

The new top is meant to look familiar. EBMUD says the replacement operating house will be lightweight metal and closely resemble the old design.

Before it can go on, crews have to build new corbels, the supports, and a new floor inside the existing tower. The August update scheduled the operating house for installation by November 2026. After that come electrical work, testing and commissioning.

The rest of the job happens out of sight. EBMUD's August report to its board scheduled fall 2026 demolition at the valve vault on the dam face, where the spillway and outlet conduits run, with the conduit retrofits to follow in 2027.

"As the seasonal environmental work window closes later in the Fall of 2026, crews will pause work on the tower components and return during the next permitted work window in the Spring of 2027 to install the new underwater slide gates and electric motor operators."

That's from EBMUD's update on the Chamber page. The tower is expected back in full operation by fall 2027, and EBMUD's September 2026 board materials schedule the full Tower Safety Upgrade Project, conduits included, for completion by March 2028.

Walking the loop while the work goes on

The reservoir draws more than a million visitors a year, and construction work has been limited to weekdays to keep weekend disruption low. Here is what EBMUD has told visitors to expect:

• Trail crossings. Crews move equipment across the paved Lakeside Nature Trail to reach the park's exit road. Flaggers work at the main gate and along the trail, and pedestrians and drivers can see occasional 10- to 15-minute delays.
• Noise near the barge ramp. The tower work and EBMUD's wastewater collection system project have both been active this fall near the Lakeside Nature Trail and barge ramp area.
• Open recreation. Fishing, hiking and picnicking stay open, with changing conditions near the work sites. EBMUD's update said no vehicle closures were planned for the tower project.
• The usual routines. The paved Lakeside Nature Trail is 2.7 miles and the unpaved Rim Trail is 4.7 miles. Bikes, skates and scooters are allowed on the paved trail Tuesday and Thursday afternoons and Sunday mornings until noon. Boat rentals run from opening until 4 p.m., priced from $15 for up to an hour to $35 for five hours or more, according to EBMUD's Lafayette Reservoir recreation page.
• Parking. Daily parking for a car, motorcycle or small van is $7 under EBMUD's 2026 fee schedule. Some spaces may be used for equipment storage during key construction periods.

The Rim Trail gives the best view across the water to the tower. From up there, the scaffolding and the new, lower stem make the change in height easy to see.

The swallows, and the pieces that came down

Two loose ends from the old tower are still in motion. The first is the swallows that return to the tower each year. During the work, EBMUD put netting on the tower to keep birds from nesting, and at its February public meeting the utility said the swallows will be able to come back once construction is finished. A biological monitor has been on site each workday from May through October.

The second is the concrete itself. Residents asked whether pieces of the original tower could be saved, and EBMUD said it planned a historic token for the public. In September, according to EBMUD's monthly report to its board, staff met with Lafayette Councilmembers John McCormick and Jim Cervantes and City Manager Niroop Srivatsa about a commemorative display, covering its scope, budget and timeline. A follow-up meeting on September 18 was set to finalize the discussion. EBMUD staff are continuing to work with those city representatives on the final display.

That means part of the 1929 tower, the part built for a lake that never filled, should return to Lafayette as something people can see up close. Progress updates continue on EBMUD's tower project page.

If you have questions about the tower project or what's changing around the reservoir and downtown Lafayette, the team at DiMaggio Betta Group would love to hear from you. Get in Touch.