Is shoreline development having positive or negative impacts on ecological function?

Preliminary analysis of net gain or loss of shoreline ecological function under the current Shoreline Master Program (SMP).

by Albert Greiner, Director, Bainbridge Shoreline Homeowners

Summary

City and state planners, environmental organizations, and a variety of paid consultants would like us to believe that shade caused by docks and over-water structures is harmful to early-stage salmon. They ignore the fact that many aquatic species prefer shade, unless they are arguing for the preservation or restoration of view-blocking, “native” vegetation.

These good folks would also like us to believe that by preventing erosion of our shoreline properties, bulkheads keep vital environmental elements (sand & gravel) from reaching the beach and providing habitat for a variety of aquatic plants and animals.

Since January 2008, almost 6,600 square feet of opaque dock decking has been replaced with grated decking that enables light to reach the water below. During this time, 1,126 square feet of new grated deck was permitted, as was 1,490 square feet of new opaque decking.

These additions amount to 16 thousandths of one percent of the total area accessible to sun-loving fish during the time a maximum high tide covers all of this area. As for “cumulative impacts”, it would take one hundred years to shade, or partially shade, an additional 1.6% of the Island’s shoreline.

Also since January 2008, there has been a net gain of 510 feet of new shoreline armoring. This amounts to 18 hundredths of one percent of the island’s shoreline. At this rate, another 18 percent of the shoreline would be armored in 100 years. However, mitigation agreements required by the HPA’s will provide systematic placement of sand & gravel on the armored beaches providing “no net loss”.

But wait, there’s more! (smile) When we combine the data from shoreline permits and restoration projects, we see that there has actually been a net reduction of 1,930 lineal feet of shoreline armoring over the last few years.

Based on this preliminary analysis, we recommend that the updated Bainbridge Island Shoreline Master Program should include a requirement that the City’s planning staff keep a running total of additions, changes and restoration factors. It’s the only way we will ever know if there is a net loss or net gain in environmental function as defined by the Department of Ecology.

Docks and Over-water Structures

Based on a review of Washington Department of Fish and Wildlife (WDFW) Hydraulic Project Approvals (HPA) issued from January 2008 to July 2010 for Bainbridge Island docks and over-water structures:

• 25 HPA’s were issued in this period
• 6,598 square feet of opaque dock decking was replaced with grated decking
• 1,126 square feet of new grated deck was installed
• 1,490 square feet of new opaque deck was installed

In addition:

• 117 creosoted pilings were removed
• 141 concrete or steel piling were installed

This represents a reduction of 5,108 square feet of opaque overwater deck, and a gain of 7,724 square feet of grated overwater decking.

For perspective, most decks and floats are less than 60’ long. The square footage of the island’s tidelands and waters 60’ from the ordinary high water mark (OHWM) is approximately 53 miles x 5,280 feet per mile x 60 feet, which equals 16.8 million square feet.

Thus, the new opaque and grated decking (2,616 square feet) constitutes a reduction of about 0.016% or 16 thousandths of one percent of the total area accessible to full-sun-loving fish during the time a maximum high tide covers all of this area. As for “cumulative impacts”, it would take one hundred years to shade, or partially shade, an additional 1.6% of the Island’s shoreline.

Bulkheads — aka Shoreline Armoring

Using WDFW Hydraulic Project Approvals issued from January 2008 to July 2010 for Bainbridge Island shoreline modifications (bulkhead repairs, removals, replacements & installations — also permitting restoration of private shorelines):

• There were also 25 of these HPA permits issued in this period.
• 11,944 square feet of new tideland was exposed due to removal of bulkheads or relocating existing bulkheads landward
• A net gain of 323 lineal feet of new rock bulkheads was installed.
• A net gain of 187 linear feet of soft armoring was installed
• 386 lineal feet of shoreline received large woody debris (large logs with root balls attached) installed in front of bulkheads
• As mitigation, property owners agreed to deposit 1,574.5 cubic yards of approved “fish mix” sand & gravel over various time periods
• 200 linear feet of concrete bulkhead was replaced by lower reflectivity rock bulkhead

For perspective, the net gain of 510 feet of new shoreline armoring is 0.18% or 18 hundredths of one percent of the island’s 53 miles of shoreline.

Using data reporting shoreline restoration projects on Bainbridge Island, most classified as active projects:

• $5,742,690 was budgeted for restoration projects
• 2,440 linear feet of shoreline armoring were removed
• 108,640 square feet of tidelands/marsh were restored
• 870 cubic yards of debris was removed from tidelands
• 23,500 square feet of nearshore vegetation was restored to native plantings
• 196,020 square feet of eelgrass beds were planted
• 300+ piles were removed
• 435 linear feet of shoreline received deposits of “large woody debris”
• 265 feet of jetty to be removed (Blakely)
• 2,750 square feet structure to be removed (Blakely)

When combining the data from shoreline structure permits and restorations, we see that there has been a net reduction of 1,930 lineal feet of shoreline armoring over the last few years.

Note: Blakely Harbor Park restoration goals are included above, but I was unable to find data on the Waterfront Park shoreline restoration so any bulkhead removal and shoreline restoration there is not reflected in these numbers.

Open Space Acquisition

Using data regarding Open Space Commission Acquisitions from 2002-2007:

• 4,411 linear feet of Bainbridge shoreline was acquired and preserved with Open Space Bond money or other city funds.
• Shoreline and uplands acquired total 322.68 acres at a cost of $12,068,000.

Such acquisitions do not necessarily result in a gain or loss of ecological function unless the acquired areas are “restored”. However, it is assumed that the acquired lands provide ongoing ecological positive effects, just as it is claimed that bulkheads, docks and over-water structures cause ongoing harm.

There are limitations to this preliminary analysis.

No HPA data were available to me for 1997 to 2008. My request is now being processed by WDFW.

The permits included were HPA permits, not Bainbridge Island city permits. HPA permits do not show completion dates so I have no confirmation that the permitted work was actually done. Personal communication from a COBI staff member indicates COBI does not have accurate information on completions either.

Many permits are not specific as to tideland gains, so only those gains cited are included.

Many permits do not specify exact numbers of piles removed, so only those piling enumerated, or the minimum number cited, are included.

Some properties acquired by the OSC were acquired for less than fair market value, it’s claimed $2,107.140 was saved in this manner.

End Note

The permitted additions and restoration projects included thus far do not span the same years. They overlap but are not congruent. My goal is to obtain and analyze HPA data from HPA 1997-2007. I also hope to obtain data about restorations planned or completed by the Puget Sound Partnership, the Salmon Recovery Board, and others. Projects like Strawberry Cannery Park have been included even though they are not complete, as funding appears to be secure.

I hope the preliminary information can be used to point out that shoreline activity is not always harmful and that the city’s cumulative impact study should be structured to include all positive shoreline activities as well as purported negative impacts.