Valley Water District and Google collaborated on an infrastructure project to enhance flood mitigation in Sunnyvale, California. The established Sunnyvale West Channel was successfully enlarged to deliver updated 100-year flood protection and concurrently create prime habitat for local aquatic species. The image provided illustrates the Sunnyvale West Channel prior to the construction phase.

Three years after project completion, this aerial view documents the established conditions. The photograph clearly shows the widened channel and the successful recovery of the riparian vegetation.

The diversion project commenced with crews installing an approximately 1,500ft long high-density polyethylene (HDPE) welded culvert pipe, which was carefully pulled through the channel to its designated location.

Half of the Google Caribbean Offices, shown here under construction, can be seen in the background behind the Sunnyvale West Channel, where the flume diversion pipe is installed within the channel.

To facilitate flow management, a sluice gate had to be incorporated at each terminus of the diversion pipe, providing the crew with the mechanism for operational control.

Workers are shown here beginning to secure one of the sluice gates to the HDPE diversion pipe.

The installation process mandated the use of numerous bolts to achieve the required seal and structural integrity of the sluice gate connection.

The approximately 1,500ft long diversion flume pipe has been successfully positioned within the channel and is now prepared for the installation of AquaDams®.

The installation began with a 1.5ft tall AquaDam® unrolled across the channel from bank to bank, positioned beneath the HDPE diversion pipe. Following this, the crew installed the first single closed end (SCE) AquaDam®, measuring 14ft in height and 60ft in length, directly over the initial dam and the pipe. The AquaDam® roll was carefully lifted over the pipe, after which crew members guided the material down along both sides to ensure proper placement and sealing.

This image shows two 3in blue discharge hoses extending from one of the fill tubes of the 14ft tall SCE AquaDam®. Each fill-tube is roughly equal in diameter to the full height of the filled dam, allowing for efficient water transfer during deployment.

As the 14ft tall SCE AquaDam® fills, crew members walk along the length of the diversion pipe to ensure the dam material settles properly into place, promoting a more secure and stable installation.

Two excavators were used to help stabilize the pipe while the 14ft tall AquaDam® was being filled with water. As the dam filled, the increasing hydraulic head generated forces that acted against the pipe, attempting to displace it. The excavator buckets provided resistance, counteracting the pressure from the water within the AquaDam®.

The first 14ft tall SCE AquaDam® continues to fill with water, having now risen above the flume pipe. The dam has expanded sufficiently for the roll to extend fully across the channel, reaching the opposite bank.

In order to properly install a SCE AquaDam®, it is essential to have a starting bank that maintains the open end at a higher elevation than the full height of the AquaDam®. The open end and fill-tubes of an SCE AquaDam® must remain elevated above the dam's full height along its designated path. The AquaDam® will only reach its maximum height at the lowest point along its designated path. We are looking at the starting bank in this photo.

Before the AquaDam® completed filling, workers pulled the remaining length of the roll up the far bank to ensure full deployment and proper positioning.

With the successful installation of the first 14ft tall SCE AquaDam®, the project now moves to the next location for deployment of the second identical unit. This staggered cofferdam configuration positions one dam upstream and the subsequent dam downstream to isolate the work zone.

This location is designated for the deployment of the second 14ft tall SCE AquaDam®, where the project design incorporates two distinct sections of pipe. The crew completed the prerequisite step of installing a 1.5ft tall SCE AquaDam®, which is essential for creating an impervious base seal directly below the twin diversion pipes.

The second 14ft tall SCE AquaDam® is being transported to its designated starting bank. AquaDams® are shipped rolled like a carpet around a wooden beam, enclosed in a protective covering, and equipped with lifting ropes or straps to facilitate safe handling and placement.

Workers had already installed and partially filled the 1.5ft tall SCE AquaDam®. Based on prior experience, Aqua Dam Inc. recommends filling the shorter AquaDam® only after the larger unit has been installed, as this sequence typically yields better results. However, in this particular application, the early filling of the smaller dam proved effective.

During the installation of the 14ft tall SCE AquaDam®, heavy equipment was required to lift the rolled dam over the two diversion pipes as the unit was actively being filled with water. This approach ensured proper placement and minimized the risk of displacement during deployment.

With the second 14ft tall SCE AquaDam® now unrolled over the first diversion pipe, the crew has initiated the water-filling process. As with the initial installation, it was necessary to secure the pipe in place during filling to counteract the lateral forces generated by the increasing hydraulic pressure within the AquaDam®, which could otherwise displace the pipe.

The AquaDam® roll has now been positioned over the second diversion pipe and the unrolled portion continues to fill with water, gradually expanding to conform around the pipe and secure its placement within the channel.

This time, only a single excavator was required to stabilize the pipe while the AquaDam® was being filled with water.

To reinforce each 14ft tall SCE AquaDam® on the work area side of the cofferdams, additional support units measuring 8ft in height, 17ft in width, and 35ft in length were deployed. These support AquaDams® enhance structural stability and provide an added layer of security for the work zone during construction activities.

The first 14ft tall AquaDam® has been fully installed and filled. Notably, the dam reaches its maximum height only at the center of the channel, where the depth is greatest. This variation in elevation reflects the natural contour of the channel bed and demonstrates how the AquaDam® conforms to site-specific conditions during deployment.

The downstream 8ft tall SCE AquaDam® has been fully installed and filled. To ensure water retention and maintain internal pressure, workers have securely fastened the fill-tubes, effectively preventing any potential leakage from the dam.

At a later date, the 14ft tall AquaDam® cofferdam system was observed to be fully operational and performing effectively.

The second 14ft tall AquaDam®, positioned at the upstream boundary, has remained fully charged and is successfully maintaining the required water diversion.

This view captures the downstream end of the cofferdam system, looking out toward San Francisco Bay.

This view looks upstream from the impounded bay water side, with the AquaDam® system in the foreground. In the distance, the Google Caribbean Offices are visible, providing a recognizable backdrop to the successful cofferdam installation.

Upstream view toward the downtown Sunnyvale, California district.

An aerial image from Google Earth Pro highlights the dry work area successfully established between the two AquaDam® installations. This clear separation demonstrates the effectiveness of the staggered cofferdam configuration and flume pipe diversion technique. Outstanding work by everyone involved, your efforts have truly paid off.