Net Gain of Ecological Function Observed on            Bainbridge Island Shorelines from 1997 to 2010              Compile...
Docks and Overwater Structures        • 52 HPAs were issued from 1997 to 2010        • 8,796 square feet of opaque dock de...
Shoreline ModificationsWe found shoreline modification permits for bulkhead repairs, removals, replacement andinstallation...
Shoreline RestorationThe following were observed from sources reporting shoreline restorations on Bainbridge Island.Most a...
Upcoming SlideShare
Loading in …5
×

Cumulative Impact Summary 1997-2010 HPAs

327 views

Published on

Published in: News & Politics
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
327
On SlideShare
0
From Embeds
0
Number of Embeds
9
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Cumulative Impact Summary 1997-2010 HPAs

  1. 1. Net Gain of Ecological Function Observed on Bainbridge Island Shorelines from 1997 to 2010 Compiled from Hydraulic Project Approvals (HPAs) issued by the Washington Department of Fish & Wildlife. by Albert Greiner for Bainbridge Shoreline Homeowners with editorial assistance by Ken SethneySummaryNew construction, damage repair, and restoration projects undertaken since our city’s ShorelineManagement Master Program was enacted, have resulted in a significant gain of shorelineecological function. When combining the data from overwater structures, shoreline modificationsand restoration projects, we have seen the following gains over the last thirteen years: • 750 linear feet reduction of hard shoreline armoring • 1,536 square feet reduction of opaque overwater structures • 523 feet of creosote treated wood bulkhead have been replaced • 583 creosote treated pilings have been or will be removed • 4,036 cubic yards of sand & gravel will nourish beaches • 28,518 square feet of native vegetation have been planted • 125,676 square feet of tideland have been or will be restored • 196,020 square feet of eelgrass have been or will be plantedConclusion“No net loss” was not the standard in 1996, but it is today. It is clear that existing policies aremore than adequate to mitigate loss and provide substantial gains.During their presentation at City Hall, Department of Ecology representatives made it clear that“no net loss” can be applied to an entire jurisdiction rather than a single project. Doing sospreads the incentives for and benefits of restoration across the entire island instead of focusingon individual homeowners or project developers.Tuesday, March 1, 2011 c 1 of 4
  2. 2. Docks and Overwater Structures • 52 HPAs were issued from 1997 to 2010 • 8,796 square feet of opaque dock deck was replaced with grated deck • 7,260 square feet of new opaque deck was installed • 1,772 square feet of new grated deck was installed • 283 creosote treated pilings were removed • 381 non-toxic pilings were installedAccording to the Army Corps. of Engineers, Washington Department of Fish & Wildlife (WDFW),and local planners, grated decking is better than opaque decking. Since 1996, we have seen anet reduction of 1,536 square feet of opaque overwater structures.1While examining the HPA documents, we observed that most decks and floats are less than 60feet long. The area of the island’s tidelands extending 60 feet from the ordinary high water markis approximately 16,790,400 square feet.2New overwater structures, both opaque and grated, total 9,032 square feet.3 This constitutes achange of about 0.054% or 5.4 hundredths of one percent in thirteen years, or 4 thousandths ofone percent per year.That amounts to one square foot of new dock surface for every 1,859 square feet of tidelandarea 60 feet from the OHWM. Summary: Any loss of ecological function caused by such a minute yearly change is far outweighed by the net reduction in opaque overwater structures.1 7,260 square feet - 8,796 square feet = -1,536 square feet2 53 miles X 5,280 feet/mile X 60 feet = 16,790,400 square feet3 1,772 square feet + 7,260 square feet = 9,032 square feetTuesday, March 1, 2011 c 2 of 4
  3. 3. Shoreline ModificationsWe found shoreline modification permits for bulkhead repairs, removals, replacement andinstallations, plus restoration permits for private shorelines. • 68 permits were issued from 1997 to 2010 4 • 1,690 linear feet of new rock bulkhead was installed • 507 linear feet of soft armoring was installed • 405 linear feet of concrete bulkhead was replaced by lower reflectivity rock bulkhead • 523 feet of creosote treated wood bulkhead was replaced by rock bulkhead • 17,036 square feet of tideland gained due to bulkhead removals & landward relocations • 2,806 linear feet of beach was improved by installing large woody debris • 5,018 square feet of native vegetation was restored • 4,036 cubic yards of beach nourishment (aka “fish mix”) has been required as mitigation over various time periods This is equal to 230 tandem wheeled dump truck loads, enough to spread 4.5 inches of sand and gravel over the island’s entire tideland area.The net permitted gain of 1,690 feet of angular rock armoring is 0.6% of the island’s 53 miles ofshoreline.5 This is slightly more than 1/16th of an inch per foot of shoreline, and amounts to anarmoring rate of 130 feet per year.Approximately 50 percent of Bainbridge Island’s shoreline has been modified in the past.6 At130 feet per year, it would take 1,076 years to modify the remaining 50 percent if it were lawfulto do so.7 However, this ignores the restoration projects mentioned below which have (or will)result in a 750 foot net reduction of shoreline armoring. Summary: Any loss of ecological function caused by such a minute yearly change is far outweighed by moving structures landward, installation of soft armoring and woody debris, and beach nourishment requirements.4 We noted a large spike in bulkhead repairs following the severe 2005-6 winter storm.5 1,690 feet / ( 53 miles x 5,280 feet/mile ) = .006 = 0.6%6 Herrera, Addendum to the Summary of Science Report for Bainbridge Island, pg 147 50% x (( 53 miles x 5,280 feet/mile ) / 130 feet/year ) = 1,076 yearsTuesday, March 1, 2011 c 3 of 4
  4. 4. Shoreline RestorationThe following were observed from sources reporting shoreline restorations on Bainbridge Island.Most are classified as active projects. Blakely Harbor Park restoration goals are included butthat project is still being studied as to feasibility. We were unable to find data on the WaterfrontPark shoreline restoration, so bulkhead removal and shoreline restoration for that project is notincluded in the following numbers. • 2,440 linear feet of shoreline armoring removed • 108,640 square feet of tidelands/marsh restored • 870 cubic yards of debris removed from tidelands • 23,500 square feet of nearshore vegetation restored to native species • 196,020 square feet of eelgrass planed • 300+ creosote treated pilings removed • 435 linear feet of shoreline received large woody debris • 265 feet of jetty to be removed (Blakely) • 2,750 square foot structure to be removed (Blakely) Summary: Restoration is intended to cause a net gain of ecological function. With limited information, we have been able to track these significant gains.Limitations of Data Included • Hydraulic Project Approval (HPA) data was furnished under a public records request made to the Department of Fish and Wildlife. • All shoreline work requires an HPA before any city permit may be issued. • Many HPAs are not specific as to tideland gains, so only those gains cited or calculable from applications are included. There are more gains than totaled here. • Many HPOs do not specify numbers of piles removed, so only those pilings enumerated are included. More pilings have been removed than totaled here. • The permits mentioned were HPA permits, not Bainbridge Island city permits. • HPA permits do not show completion dates, so there is no confirmation that the permitted work was actually completed. • Personal communication from a COBI staff member indicates COBI has no reliable way of reporting project completion.Tuesday, March 1, 2011 c 4 of 4

×