Background:
The primary design reference available for engineers to design public infrastructure projects within City of Ashland was developed in the early 1970s. There have been considerable changes in both the engineering design community's practices and the City's approach to development standards since then, and the document had become outdated. The City of Ashland typically adopts the Oregon Department of Transportation (ODOT) and/or the American Public Works Association (APWA) standards by default. The City of Medford faced a similar situation, and this problem was common to other communities in the Rogue Valley. In response to a growing need for standard engineering practices and a need to acknowledge specific elements for individual communities, engineers from Medford and Ashland Public Works Departments began meeting regularly to develop a standard that could fit both cities. The City of Eugene's manual was used as a starting point and the standards were modified to include information from many other sources.
Over the past two years, it has been staff's goal to develop a consistent and comprehensive set of engineering standards for public infrastructure improvements. The document that has been produced exceeds that expectation. Ashland's engineering staff along with the City Engineers of Medford, Jacksonville, and several other communities and special districts in the area, have worked together to build a consistent set of basic engineering standards. The standard is organized to allow specific agencies to incorporate their community specific requirements in a consistent manner without requiring approval of other participating communities or agencies. The document includes common standard details and specifications that participating communities utilize in common, thereby reducing bidding complexity and construction costs for typical Public Works construction projects. Private developers building public improvements will also be required to utilize these standards. Copies of the binder containing the revised Engineering Design Standards for Public Infrastructure Improvements may be reviewed in the engineering office. After distribution and adoption by Council, updates will be available to download from the Ashland website.
The term Public Improvement refers to roadwork, pipelines, bridges, subdivisions and other publicly owned facilities constructed in public utility easements or the public right of way. It does not generally pertain to building construction, parking lots, or site work done on tax lots, even if those lots are publicly owned. Those types of construction activities are generally governed by the Building Code and inspected by the Building Department. However, as required, the private developers may also be required to build portions of their developments to public improvement standards.
While most of the new standards contain information that has changed in only small ways, several significant changes are present:
| 1. |
Storm drainage systems in Ashland will be required to include a water quality improvement component if the increase in impervious area resulting from a project exceeds a threshold of 5,000 square feet (SF).
In parts of the city where the storm drain system is presently undersized, the preferred method of improving water quality will be through "detention", which refers to systems that slow down the flow of water leaving a site, thereby allowing suspended solids to settle out before the water can reach the natural stream flow. These systems are already widely in use, and they not only improve water quality, but also improve the conveyance capacity of our storm drain system.
In parts of the city where the storm drain system is adequately sized, bio-swales and other accepted natural methods of improving water quality are the preferred method. The requirements currently exceed minimum standards, but these measures were introduced in the City's 1999 Storm Water and Drainage Master Plan and will contribute towards meeting anticipated NPDES phase 2 requirements. |
| 2. |
New requirements for additional preservation of historical markers and unique historical public works structures are included to prevent disturbing Ashland's history. |
| 3. |
Ashland's water system construction standards have been tightened, and although we retain some unique characteristics, they will more closely match Medford Water Commission standards. |
| 4. |
The Ashland Electric Department has recently changed from previously providing new facility construction to now requiring that private developers construct new electrical distribution system facilities. This required new performance standards be developed for that work with the City reviewing design, construction and inspections. The electric department has done most of that work, but the standard is included with this manual to facilitate distribution and improve awareness of the changes. |
| 5. |
Landscaping Standards developed for the Ashland's Parks Department are now being implemented citywide. Tree protection, erosion control, and other environmental protection efforts initiated by various commissions and the Community Development Department are emphasized in the specifications to ensure that implementation of these requirements is clearer and easier. |
| 6. |
Electronic As-Built Survey drawings will now be required upon completion for all public improvements in order to obtain accurate location information that can be readily incorporated into our GIS system and made readily available to the public through the Jackson County Smartmap system (www.smartmap.org). |
In August of 2003, the draft was released to the local engineering community for review and comment, and in December, a group of those engineers proposed that a comprehensive review be undertaken by a representative group of local engineers, developers, surveyors, and contractors. A technical advisory group (TAG) was proposed and then formed, and their review is nearing completion. Representatives from the Rogue Valley Sewer Services (formerly known as BCVSA) are also participating, and the relatively recently consolidated ODOT/APWA standard construction specifications have been incorporated into the document to provide as much standardization and coordination with state agencies as practical/possible. The Technical Advisory Group has proposed to continue to meet on a regular basis to review updates to the manual to keep it current and useable. The Public Works Director would be responsible ultimately for accepting any proposed revisions. |
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