I’ll be doing some renovations to my property which may be subject to the new development requirements for managing stormwater on-site. Do I get a discount and is there any way that I can retrofit my property to manage more stormwater than I would otherwise be required to?
A: When it rains, stormwater flows from roofs, roads, parking lots, and other hard surfaces. This stormwater runoff contributes to stream pollution and habitat destruction, and costs the city millions of dollars to manage each year. By properly self-managing stormwater on your property, you help mimic nature and reduce stormwater’s damaging effects.
A: No. Property owners that manage a portion of their stormwater will still qualify for partial stormwater discounts. In fact, slowly incorporating new stormwater management facilities as your time and budget allows is encouraged. Simply re-register each time you make stormwater improvements to your property.
A: Your stormwater charges help pay for a comprehensive system of stormwater management and drainage services throughout the City of Portland. The charge includes costs for maintaining stormwater sumps, drainage ditches, storm sewers, and keeping Portland ’s streets clear of flooding. It also covers the costs of programs that keep stormwater pollutants from entering Portland ’s rivers and streams. The discount reflects the amount of stormwater that private properties contribute to the overall stormwater system (equivalent to 100% of the on-site stormwater charge, which is equal to 35% of the sum of the total stormwater charges).
A: The Clean River Rewards stormwater discount program is separate from previous discount programs. Current ratepayers must register their properties since property ownership or other site conditions may have changed. Once a property is registered, you will not have to re-register unless site conditions or ratepayer information changes.
A: Not necessarily. The Downspout Disconnection Program focused on downspouts that are simple to disconnect and require little additional site work. There might be more complex solutions that would work for your site such as re-hanging a gutter to disconnect to an appropriately landscaped area, or re-grading the area adjacent to your downspout so that stormwater flows away from your building. You may need to take additional steps in order to make sure that on-site stormwater management can be done safely. Partial Clean River Reward credits are also offered to properties that have any of the following conditions:
- Four (4) or more trees that are 15 feet tall or larger
- Any portion of a building covered with an ecoroof
- Less than 1,000 square feet of total hard/impervious area
A: Many east county properties already have drywells that manage their stormwater. In some areas of Portland, you may have to implement some additional safety measures or alternative stormwater management options to ensure appropriate onsite stormwater management. Refer to the city’s Site Assessment Guide and the Stormwater Solutions Handbook for other stormwater management options that may work for your site. The city also offers on-site technical assistance that can help ratepayers determine suitable stormwater options for their site.
About the Discount
A: No. Directly discharging stormwater to a stream can harm stream and watershed health. The Clean River Rewards discount is intended to reward property owners that dispose of stormwater on-site, thereby lessening the impact on the environment. Even holding and re-releasing, or slowing water as it leaves your site provides benefits and would qualify for a partial discount. For example, before releasing to a stream, detain your water in a flow-through stormwater planter. Managing stormwater runoff before it flows to streams helps reduce pollution and erosion problems that impact our watersheds, and in turn enhances urban wildlife habitat.
A : It depends on several site specific factors. The best solution is to call for assistance at 503-823-1371. We will help you with your situation and the registration process.
A: Not through the regular registration form, but the tree discount is appealable. For residential customers, the total tree canopy (the reach of the branches) must be equivalent to at least 200 square feet to appeal the tree credit. Attach a letter to your registration form asking for the tree discount because you have sufficient tree canopy to qualify for the tree discount. Program staff will check your property on aerial maps and get back to you to tell you if you qualify.
A. Yes, if the trees are located on your tax lot.
A: Yes, as long as the overflow is managed on-site as well. Considering the average Portland home generates about 22,500 gallons of stormwater per year, rain barrels and cisterns usually do not have enough stormwater capacity to be considered stand-alone stormwater disposal options.
Q: I’ll be doing some renovations to my property which may be subject to the new development requirements for managing stormwater on-site. Do I get a discount and is there any way that I can retrofit my property to manage more stormwater than I would otherwise be required to?
A: Yes. The discount applies to all properties that manage stormwater onsite, regardless of circumstance. When you are making changes to your site, such as adding a garage or extending your house into a back lot, you will be required as part of the building permit process to add stormwater management facilities for runoff created by the new impervious surfaces you add. Renovation is a perfect time to add stormwater facilities. If you have to build a facility to meet permitting requirements then consider over-sizing the facility to take runoff from the existing rooftops and paved areas as well. The discount is based on a sliding scale according to how much stormwater you manage, so the more you manage on-site, the bigger your discount.
A: Yes. However, drywells typically have a life expectancy of 20 to 30 years, so be sure that they are still functioning properly. Also note that any new underground stormwater facilities (such as drywells and soakage trenches) must be registered with the Oregon Department of Environmental Quality under the Underground Injection Control (UIC) Program. If you have a commercial site there may be additional requirements as part of that registration.
About Stormwater Facilities
A : Drywell and soakage trenches will eventually clog with debris from stormwater runoff and no longer function properly. When a drywell or soakage trench fails, you will know because it will likely overflow at your downspout. The overflow could also be from clogged standpipes or other failed plumbing. You might see moisture and dampness in your basement near the downspout, or depressions and settling in areas over your drywell or pipe system. Small sink holes and other settling is a sign that the drywell, soakage trench, or pipe has collapsed and needs replacement. If you must replace a failing system, consider using surface facilities for runoff management. They have longer life expectancies, are easier to access for maintenance, can blend in with your landscaping, and do not require registration with the Oregon Department of Environmental Quality.
A: Several stormwater management solutions will work on most sites. To understand what facilities might work at your site, read the Site Assessment Guide and Stormwater Solutions Handbook. Then choose one or more facilities that best suit your site and budget. The city offers on-site technical assistance that can help ratepayers determine suitable stormwater options for their site.
A: A simple infiltration test will determine if there is adequate soil infiltration:
- Dig a 24” round and 24” deep hole and fill it to the top with water
- Allow the water to completely drain out
- Re-fill the hole with water and mark the top of the water level
- Wait one hour and measure how far the water level drops.
- If the water level has dropped 2” or more in that first hour, your soils are good enough to handle a stormwater facility that soaks in or infiltrates water.
A: When infiltration is not possible, flow-through or lined stormwater facilities can help slow and clean stormwater before it leaves your site. Holding, re-releasing, and slowing water as it leaves your site provides benefits and would qualify for a partial discount. You may also be able to install an oversized infiltration facility to accommodate poorly draining soils, or amend your soil by adding sand and gravel to improve drainage. If you choose to use infiltration facilities in poorly draining soils, you will likely need a professional engineer or soil scientist to sign off on your city permit application.
A: Possibly. Simple solutions such as disconnecting your downspout or minor changes to your landscape do not require a city permit. However, if your facility requires underground piping, major excavation, structure alterations, or infiltration facilities in poorly draining soils, you will need to contact the permit center and obtain the appropriate permits. Before you build, check out the Stormwater Retrofit Permits and Inspections brochure to see if your project will need a permit. When in doubt, call the permit center for additional information at 503-823-7300.
A: No, stormwater management improvements alone will not trigger requirements to upgrade existing development that does not meet current zoning requirements. This exemption allows property owners to retrofit their property with on-site stormwater facilities without the burden of bringing the entire site into compliance with the city’s zoning code (City Code 33.258.070.D.2.a.4).
A: If your facility drains within 48 hours, the length of time it takes for most mosquito larvae to hatch, the eggs dry up and die. Remember to test your soil for adequate drainage to avoid creating a potential mosquito problem. If you design a pond-like system for aesthetic reasons, you may need to manage and control potential mosquito habitat.
A : It may be possible to remove parking lot spaces to install a stormwater management facility, but it is best to check with the Planning and Zoning office first (503-823-7526) to find out if there are special land use conditions related to the parking lot. All surface parking lots must provide landscaping, so a retrofit that includes a surface stormwater facility, such as a bioswale, would meet landscaping and stormwater objectives better than an underground system. Instead of removing parking lot spaces, you can reconfigure your parking lot to utilize available unused areas. More often than not parking spaces and access drives are oversized according to current standards. Resizing and reconfiguring your parking lot can open up space for a stormwater management facility. Planning and Zoning can help you with the reconfiguration, or you can get parking lot dimension information online (City Code 33.266).
A: Installing a swale or other on-site facilities on properties where stormwater is currently conveyed directly to a stream via a pipe may be allowed depending on factors such as slope, tree removal, disturbance, and existing pipe size. Since a permit would be required for this type of work, you should contact the Bureau of Development Services Planning and Zoning at 503-823-7526 for more information and help.
A: Your options may be limited. Discharging stormwater to steep slopes increases the speed of stormwater runoff resulting in erosion. Steep slopes also limit stormwater infiltration and can create negative impacts to neighboring properties. Flow-through stormwater systems that temporarily slow and retain stormwater may be the best solution when dealing with steep slopes. The city also offers on-site technical assistance that can help ratepayers determine suitable stormwater options for their site.
A: If your roof is relatively flat and already supports a rock ballast or gravel layer (at least 3” thick) or the building was planned for additional floors, then it's likely a good candidate for an ecoroof. To be certain, however, the city requires that you consult a certified professional or produce design documents that prove your roof can hold the additional weight before permitting of an ecoroof installation. As a safety measure, designed stamped drawings from a structural engineer are usually required for ecoroof retrofits.