Design Has Started at El Manto

Posted on Monday, June 12th, 2017






This year our restoration project is located at El Manto, just a short jog down from the 2016 site, Sacramento Bar. Late May, cbec started the pre-project survey and we hope to have a preliminary design for our project team to review next month.

Looking downstream to the project


The design will include a side channel carved in the southern bank for rearing habitat, with the excavated materials placed into the river for spawning habitat (to the left). Due to the wet year, we hope to be in the river during September when the flows will be down to 3,500. We also plan on jumping downstream of San Juan Rapids (picture to the right) to fix a stranding problem from a backwater area.

Downstream of El Manto and San Juan Rapids (off to the left). This backwater presents stranding issues, and we are planning on doing some light grading to fix that.

El Manto and San Juan Rapids at 35,000 cfs

During the high flows this winter, we were able to get this aerial of the inundated at 35,000cfs.

When designing a project, we aim to understand all aspects and possible consequences. We use many methods of data collection to get a handle on optimum design for fish and to model flood control. Mary Maret, from Sacramento County Parks, joined us to identify rare populations of native plants for so we could try to avoid them during design. cbec conducts a series of surveys and other data collection techniques in order to build a robust and accurate model of the existing condition. As with each of these projects, we aim to make only positive changes in the landscape.

cbec has installed stage monitors to validate their model by collecting depth information over time for different flows. To the left is Ben Taber collecting bathymetric RTK GPS elevation data. They also collected foot and drone based topographic data. A 2D hydraulic model will be developed and used to design the best habitat suitability (depth and flow)

Keep an eye out in September for this exciting project!

Foothill penstemon. Penstemon heterophyllus

PostedMonday, June 12th, 2017