Broad Spit Drift Cell
The Broad Spit Drift Cell (SPU 2059) is a drift cell covering the southwest side of Tarboo Bay from its southern divergence north, past broad spit, ending at the spits that frame Inner Tarboo Bay.
Nearshore Strategies Data Report
Cereghino et al 2012 completed a soundwide analysis to identify and describe beach sites in Puget Sounds as part of a nearshore ecosystem restoration strategy (using remote sensing data c. 2000-2006). The following narrative was developed to support distribution and use of analysis results:
- Beach Site 2059 is a 7.48 km long beach system containing 2384 meters of barrier beacha beach formed in the absence of a eroding bluff through transport (32%) and 16 creek mouths, one of 72 beach sites located in the Hood Canal Sub-basin. Based on these attributes it ranks 97 out of 100 in terms of size and complexity among all Puget Sound Beach systems. Over five generations of beach development, 5 percent of beach length now has some indicator of sedimentparticles of clay, silt, sand, gravel, or cobble, transported by water, are called sediment. supply degradation, and 1 percent of the nearshore zone has estimated impervious levels higher than 10 percent. Property boundaries now legally segment the shoreline with an average of one property every 93 meters. Based on these metrics, this site ranks 25 out of 100 in terms of estimated degradation among all beach sites in Puget Sound. The PSNERP Strategy Analysis places this site in Degradation Group D6, a group of 44 sites with below average parcel density but still minimal evidence of nearshore development. Based on this grouping we recommend this site for a protection-based strategy, where due to low levels of degradation, a concerted effort based on protection may preserve beach ecosystem processes, thereby maintaining a high level of ecosystem services. The site faces no risk from jetty development impounding sedimentparticles of clay, silt, sand, gravel, or cobble, transported by water, are called sediment., has no impacts from active shoreline railroad, and faces a slight risk from predicted future population growth.
- This site is among 518 littoral cells that contained barrier-type embayments. Historically this system contained 3 barrier-type embayments, with an embayment shoreline of 10.78 km, encompassing 31.6 hectares of tidal wetlands - considering the length of beach this is the equivelent of one embayment every 2.5 km. This system is one among 64 barrier embayment complexes in the Hood Canal Sub-basin. Based on these metrics this site ranks 81 out of 100 in terms of size and complexity among all Puget Sound barrier embayment systems. The PSNERP Strategy Analysis placed this site in Potential Group P9, a large group of 69 sites with large embayments and wetlands at a typical density, identified as noteworthy sites for their high potential to provide ecosystem services.
- Site 2059 currently has 3 embayment--the same as under historical conditions. This has been accompanied by a 25 percent loss of wetland area and a 28 percent loss of embayment length, based on comparison to historic maps. None of the remaining embayment shoreline length has evidence of shoreline modification. Based on these metrics, and the general development status of the drift cell, the PSNERP Strategy Analysis ranked this system 20 out of 100 and placed this site in Degradation Group D1, a very large group of 172 barrier embayment systems that appear relatively undegraded by either loss of length, shoreline development or loss of sedimentparticles of clay, silt, sand, gravel, or cobble, transported by water, are called sediment. supply in the surrounding drift cell. Based on this grouping, the site is recommended for a protection-based approach, where due to low levels of degradation, a concerted effort based on protection may preserve beach ecosystem processes, thereby maintaining a high level of ecosystem services.