Planning and Research, Office of
(Office of Planning and Research)
Tinsley Island Bank Stabilization Project
NOE - Notice of Exemption
The project is limited to stabilizing a portion of eroded bank on the northern portion of Tinsley Island using bio-engineering methods based on guidance from NMFS. The technique involves placement of a mix of rip-rap and natural soil material, placement of large woody debris and replanting of riparian vegetation.
The total size of the bank will be 215 linear feet by 25 feet wide (0.12) acre. Approximately 776 cubic yards (CY) of rip-rap will be placed below mean tide level to provide the base of the stabilized bank. Approximately 338 CY of 70/30 mixture of rip-rap and salvaged native soils will be placed on the rip-rap base. 41 CY of native topsoil will be placed over the 70/30 rip-rap/soil mixture. Geotextile fabric will be placed to prevent loss of rip-rap and soil materials. Construction will be completed from a barge with a barge mounted backhoe.
the existing slope will be covered with a 70/30 mixture of rip-rap and soil throughout the project design. The rip-rap and soil mixture will be covered with additional native soil. A 5:1 slope will be created for the planting bench to make a slope in the water. The top of the new stabilized bank will serve as a riparian planting bench. Herbaceous and hardwood plantings will be used (willow cuttings and native species). Riparian planting will be done by hand Tule plants and other native emergent vegetation will be used to plant the lower region of the sloped bench to create emergent shallow water habitat. Issuance of a Streambed Alteration Agreement Number 1600-2010-0009 pursuant to Fish and Game Code Section 1602.