Author Archives: Patti Ransdell

Moorhen Marsh Construction Update- Week of July 2, 2018

Recent work performed:

  • Dewatering and fish rescue in ponds A1, A2, B and Fat Slough
  • Vegetation removal and drying.
  • Turning soil with a long-reach excavator and dozers in dewatered pond beds to further dry the soil.
  • Installation of fused HDPE to divert water in Peyton Slough.
  • Installation of sandbag cofferdam at upstream end of Peyton Slough.

Upcoming work:

  • Excavation of keyways for new levees in ponds A-2 and A-1.
  • Begin new levee construction in ponds A2 and A-1.
  • Continue Vegetation removal and drying.
  • Continue turning soil with a long-reach excavator and dozers in dewatered pond beds to further dry the soil.
  • Installation of AquaDam at downstream end of Peyton Slough.
  • Dewatering of Peyton Slough.
  • Dredging of Peyton Slough.

Moorhen Marsh Closed to the Public As Phase B Work Commences

Moorhen Marsh is closed to the public as pre-construction activities related to Phase B work on the Moorhen Marsh Western Pond Turtle Habitat Enhancement Project begin.  Some of the pre-construction activities underway include pond dewatering, fish rescue, vegetation cutting and installation of the wildlife exclusion fence.  Currently, Moorhen Marsh is anticipated to be closed to the public through February 3, 2019.

The Moorhen Marsh Western Pond Turtle Habitat Enhancement Project will include wetland and riparian habitat improvements, installation of the new ADA trail, the construction of the viewing platform and board walk, a second dip-netting site for school students, and enhancements to wetland and riparian habitat to benefit western pond turtle, North American river otter, green heron, and black-crowned night heron.

Construction Updates- Week of March 19, 2018

The majority of Phase A construction is finished. Below are highlights of construction activities completed in February and early March:

  • Completed terrestrial plantings (except for dip netting area)
  • Installed irrigation system
  • Installed the retaining wall in the dip net area in Pond E
  • Hydro-seeded levee trails

The remaining tasks to complete Phase A are listed below and MVSD expects all work to be completed by April 6th:

  • Install decomposed granite between the vehicle bridge and dip netting area
  • Install landscape boulders and picnic bench at dip netting area
  • Install terrestrial plants around dip netting area
  • Install emergent vegetation in Ponds C, D, and E
  • Install canal gates
  • Fill Ponds C, D, and E

Construction Updates for the Week of November 27,2017

Following is a summary of main work items performed recently:

  • Completed reconstruction of the levees in ponds C, D and E, utilizing geo-grid.
  • Placed the finish soil over the reconstructed levee slopes.
  • Completed excavation and forming the deep water channels in ponds C, D and E.
  • Completed construction of the island in pond C and partial construction of the island in pond D.
  • Removed three of the existing canal gates and began piping extensions.
  • Cut/fill and grade pond bottoms to correct elevations.
  • Wallace-Kuhl (field geotechnical) took in-situ density tests and moisture contents for compacted levee and island construction.

Upcoming work:

  • Complete construction of the island in pond D.
  • Install pipe extensions at water control structures and canal gates.
  • Refurbish and reinstall existing canal gates
  • Install rip rap at water control structures and canal gates.
  • Final grading of pond bottoms to correct elevations.
  • Begin hardscape installation (retaining wall, basking logs etc.).
  • Begin installation of erosion control blanket on levee slopes.
  • Begin planting and seeding.

Construction Updates for the Week of November 6, 2017

Progress continued for the habitat enhancement project throughout October and into November for Phase A. The following highlights the construction tasks completed last month:

  • Completed reconstruction of 95% of all the levees in ponds C, D and E, utilizing geogrid.
  • Placed the majority of finish soil over the reconstructed levees.
  • Continued excavation and forming the deep water channels in ponds C, D and E.
  • Constructed the island keyways in ponds C and D.
  • Began construction of the islands in ponds C and D, utilizing geogrid.
  • Installed the two new water control structures between ponds C/D, and ponds D/E.
  • Cut/fill and grade pond bottoms to correct elevations.
  • Wallace-Kuhl (field geotechnical) took in-situ density tests and moisture contents for compacted levee keyways and levee reconstruction.
photo of a Western Pond Turtle

MVSD Publishes Management Recommendations in Scientific Journal – Western Wildlife

In conjunction with data collected during the Western Pond Turtle Study, consulting biologist Jeff Alvarez and District Biologist Kelly Davidson, along with biologist Gary Kittleson and reptile veterinarian Louisa Asseo, co-authored an article on the potential of injury and mortality to western pond turtles during upland vegetation maintenance activities like mowing and disking. The article was accepted for publication by the journal of the Western Section of the Wildlife Society, Western Wildlife, and was published online October 23rd.

Western Wildlife is an open-access, peer-reviewed journal that publishes original research, notes, reviews, perspectives, and correspondence on the ecology, natural history, management, and conservation biology of animals. You can access the current volume at the Western Wildlife website here: http://wwjournal.org/home/current_volume/.  You can access the article on our website at this link

 

Construction Completed through the week ending September 15, 2017

Following is a summary of main work items performed recently:

  • Completed approx. 80% of levee keyways in ponds C, D and E.
  • Partially excavated and formed the deep water channels in ponds C, D and E.
  • Imported and placed select fill for pond C east levee, where the levee was seeping from raised slough water levels.
  • Began reconstruction of the levees in ponds E and D utilizing geogrid.
  • Continued moisture conditioning pond soils.
  • Continued dewatering local ponding water in ponds C, D and E.
  • Wallace-Kuhl (field geotechnical) took in-situ density tests and moisture contents for compacted levee keyways and levee reconstruction.

Upcoming work:

  • Complete levee keyways in ponds C, D and E.
  • Continue excavation and forming the deep water channels in ponds C, D and E.
  • Continue reconstruction of the levees in ponds E, D and C utilizing geogrid.
  • Cut/fill and grade pond bottoms to correct elevations.
  • Start removing and replacing water control structures.

 

Construction Update for the Week ending September 1, 2017

Following is a summary of the main work items performed in Moorhen Marsh recently:

  • The contractor continued drying (wind-rowing and disking) pond soils to correct moisture content.
  • The contractor continued dewatering local ponding water in ponds C, D and E.
  • Workers excavated some of the levee keyways in ponds C, D and E, installed fabric and backfilled and compacted.
  • The contractor began forming the deep water channel in pond E.
  • Wallace-Kuhl (field geotechnical) took in-situ density tests and moisture contents for compacted levee keyways and pond bottoms.

The following is a summary of upcoming work:

  • Continue drying (wind-rowing and disking) pond soils to correct moisture content.
  • Continue dewatering local ponding water in ponds C, D and E.
  • Complete the levee keyways in ponds C, D and E, including fabric installation and backfilling/compacting.
  • Continue forming the deep water channels in the pond bottoms.
  • Begin levee reconstruction using geogrid.
  • Import fill material for east levee of pond C.

Construction Update- Week of August 14, 2017

  • Last week, (week of August 7) the contractor had to deal with high water levels in Peyton Slough causing water to leak into pond C.
  • The main work items last week involved dewatering pond C and re-drying the soils there.
  • The contractor also continued to dry/moisture condition soils in ponds D and E.
  • This week (Week of August 14) the contractor plans to continue drying/moisture conditioning the soils in ponds D and E and will hopefully be doing some grading/compaction for the new ponds.
  • This week the contractor will continue to dewater pond C and may be able to start work on the pond C levee if suitable import material is located to cap the levee.

Coast Cleanup – Invasive Plant Removal in McNabney Marsh

Saturday, September 16

9:30 am – 11:30 am

Please join us on Coast Cleanup Day – September 16 – to remove invasive stinkwort (Dittrichia graveolens) from the edges of McNabney Marsh. Stinkwort was first reported in California (Santa Clara County) in 1984. It has now spread to 36 counties including Contra Costa. Stinkwort is not palatable, can be poisonous to livestock, and can cause contact dermatitis in people. It is found primarily along roadsides and other disturbed sites. Unlike many annuals, stinkwort flowers and produces seeds from September to December – so this is a good time to remove it. If you are up for a little work, you can help us make a big difference in the spread of this invasive plant. Reservations and signed liability forms are REQUIRED. We will provide: latex gloves, plastic bags, water, and a pizza lunch at the end of the day. Participants bring: work gloves, a hat, and sunscreen and wear long pants and closed-toed shoes. A mat or knee pads are also recommended. For more info and to RSVP, contact Heidi Petty at: hpetty@ccrcd.org.