http://waterbydesign.com.au/forum/ WSUD en-US Sat, 04 Feb 2012 14:57:54 +0000 http://bbpress.org/?v=1.0.2 q http://waterbydesign.com.au/forum/search.php http://waterbydesign.com.au/forum/topic.php?id=375#post-639 Mon, 23 Jan 2012 14:00:08 +0000 Andrew O'Neill 639@http://waterbydesign.com.au/forum/ <p> Smidy,<br /> See link to a paper which discusses disposal of plant material that is contaminated with heavy metals: <a href="http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=9100FZE1.txt">nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=9100FZE1.txt</a> </p> http://waterbydesign.com.au/forum/topic.php?id=375#post-638 Mon, 23 Jan 2012 13:00:08 +0000 Andrew O'Neill 638@http://waterbydesign.com.au/forum/ <p>Hi Smidy, Interesting question but a bit more information would be really helpful:</p> <p> - what sort of system is it? (stormwater, wastewater, other industrial?)<br /> - what sort of plants do you have, in particular, which ones do you suspect or know are taking up toxins?<br /> - when you say toxins, are you talking about metals or something else?<br /> - if metals, which ones? (Pb, Hg, Zn, Cu or others?) </p> <p>There will be different processes and disposal requirements based on the answers to these questions. </p> <p>Phytoremediation has been very well studied particularly in the US. There are a lot of resources available from the USEPA.</p> <p> cheers,<br /> Andrew </p> http://waterbydesign.com.au/forum/topic.php?id=375#post-637 Fri, 20 Jan 2012 20:32:31 +0000 SMIDY 637@http://waterbydesign.com.au/forum/ <p>Hi, I am new to this topic. I am wondering if plants that take up toxins are safe to dispose of in green waste or is there somewhere they should go? Is there a website someone can point me to for this topic if it is not a definite thing?</p> http://waterbydesign.com.au/forum/topic.php?id=374#post-636 Wed, 18 Jan 2012 10:46:22 +0000 Andrew O'Neill 636@http://waterbydesign.com.au/forum/ <p>Hi again,</p> <p>The Queensland Development Code Mandatory Part (MP) 4.3 requires alternative water use for flushing toilets and other uses (<a href="http://dlgp.qld.gov.au/resources/laws/queensland-development-code/current-parts/mp-4-3-alternative-water-sources-commercial-buildings.pdf" title="Queensland Development Code MP 4.3">http://dlgp.qld.gov.au/resources/laws/queensland-development-code/current-parts/mp-4-3-alternative-water-sources-commercial-buildings.pdf</a>). &nbsp;This doesn't need to be rainwater but it reasonable to assume at a preliminary stage that this would be used. &nbsp;You will need to estimate the required roof areas to toilets (for number of pedestals per GFA, you can eitehr use the acceptable solutions in the QDC, or you can check up the Building Code of Australia). &nbsp;The main thing to note here is that including rainwater harvesting for toilet flushing in commercial and industrial developments using this approach doesn't make a big difference to the performance of your treatment train (i.e. does not dramatically reduce the size of bioretention or other treatment technology used). &nbsp;If you want to do a more "enhanced" rainwater/stormwater harvesting strategy, this can provide greater benefits, but requires some more detailed thinking about where the demands are going to come from, and how the water will be treated and used appropriately.</p> <p>Hope this helps.</p> <p>Andrew</p> http://waterbydesign.com.au/forum/topic.php?id=374#post-635 Wed, 18 Jan 2012 10:35:09 +0000 Andrew O'Neill 635@http://waterbydesign.com.au/forum/ <br /> http://waterbydesign.com.au/forum/topic.php?id=373#post-634 Tue, 17 Jan 2012 16:45:03 +0000 stormw 634@http://waterbydesign.com.au/forum/ <p>Thanks Andrew for your reply.</p> http://waterbydesign.com.au/forum/topic.php?id=374#post-633 Tue, 17 Jan 2012 16:44:16 +0000 stormw 633@http://waterbydesign.com.au/forum/ <p>Hi,</p> <p>I am aware that in the MUSIC modelling guidelies p26, it says that situations vary for industrial/commercial rainwater tank reuse. Is there however, a recommended reuse value for preliminary design of industrial/commerical developments, where the operation for post-development is unknown at this stage?</p> <p>Thanks.</p> http://waterbydesign.com.au/forum/topic.php?id=373#post-632 Tue, 17 Jan 2012 15:20:43 +0000 Andrew O'Neill 632@http://waterbydesign.com.au/forum/ <p>Hi there,</p> <p>It really makes no difference what you put for the baseflow PE values for roof nodes. I would recommend that you put zero to make it really clear to anyone looking at the model later on that this is deliberate as there are no baseflows from roof areas.</p> <p>cheers,</p> <p>Andrew</p> http://waterbydesign.com.au/forum/topic.php?id=373#post-631 Tue, 17 Jan 2012 13:00:26 +0000 stormw 631@http://waterbydesign.com.au/forum/ <p>Hi,</p> <p>On page 16 of the MUSIC modelling guidelines, Table 3.8 lists the pollutant export parameters for split catchment land use.</p> <p>The baseflow parameters for roof surfaces is N/A. What are we suppose to input into MUSIC? Do we use zero, or adopt the baseflow values for 'lumped' catchment land use on the following page, Table 3.9?</p> <p>Thanks.</p> http://waterbydesign.com.au/forum/topic.php?id=364#post-624 Mon, 05 Dec 2011 11:36:24 +0000 Jack Mullaly 624@http://waterbydesign.com.au/forum/ <p>Two common issues which limit the size of bioretention basins are:</p> <ul> <li>Constructability</li> <li>Dealing with flows</li> </ul> <p><strong>Constructability</strong>. A number of issues present themselves when constructing larger basins. A commonly stated one is the ability to lay the various media without crushing the underdrainage or unsuitably compacting the previous layers. I suspect there is further discussion of this in the C&amp;E guidelines.</p> <p><strong>Dealing with flows</strong>. Again multiple issues here. Large basins are built to treat larger catchments and thus receive larger inflows. When this inflow is concentrated, scour around the inlet is a difficult problem. Equally, due to the porosity of the filter media, in small rain events, those plants furthest away from the inlet receive significantly less water than those closest. This often results in plant death due to a lack of water, increased weed incursion and ultimately higher maintenance costs.</p> <p>Maximum sizes in the order of 1000 to 1200m2 are often quoted. However its possible to build smaller systems which suffer the same problems, and larger systems which don't. It all comes down to smart design and good construction.</p> <p>Hope that helps</p> <p>Thanks</p> <p>Jack</p> http://waterbydesign.com.au/forum/topic.php?id=364#post-621 Fri, 02 Dec 2011 14:04:49 +0000 Tilake 621@http://waterbydesign.com.au/forum/ <p>Any thoughts or suggestions regarding the acceptable maximum size of a single Bio-retention basin....?</p> http://waterbydesign.com.au/forum/topic.php?id=363#post-620 Wed, 30 Nov 2011 07:41:04 +0000 amy4551 620@http://waterbydesign.com.au/forum/ <p>Does anyone know, or can anyone point me in the direction of a paper that describes how the values for swales in MUSIC were derived?</p> <p>Any help is much appreciated.</p> http://waterbydesign.com.au/forum/topic.php?id=362#post-619 Tue, 29 Nov 2011 14:06:52 +0000 JJ 619@http://waterbydesign.com.au/forum/ <p>BenniG,</p> <p>ECES has helped design and construct many swale systems , some having light vegetation, others with turf, and some with mainly rock having a sediment forebay, so it seems there is more than enough design options to create a very effective absorption swale. We have used modular cells as a collection and re use tank below these swales, very effectively for many years, some of which collect and store many megalitres for re use. Please contact ECES P/L. 07 32857000 - <a href="http://www.eces.com.au">http://www.eces.com.au</a></p> http://waterbydesign.com.au/forum/topic.php?id=361#post-618 Thu, 24 Nov 2011 12:42:12 +0000 brettibbo 618@http://waterbydesign.com.au/forum/ <p>We have developed checklists for the maintenance and operation of constructed stormwater wetlands for use by council. Did not really get involved with the costing but I imagine if you allocated hours against the checklist then you could come up with a reasonably accurate estimate. I know from experience that weed control can be an significant ongoing cost, particularly in poorly designed systems. I believe the key is good plant selection in the wetland from the beginning, including a range of species suitable to &nbsp;the conditions, different sizes, including ground covers and weed suppressents. If some time is invested in getting these established then ongoing costs associated with weed management can be reduced. Weeds are great at recolonizing disturbed areas, if, for instance, there is a spill event in the catchment that knocks out an area of vegetation then weeds are first to establish and spread from there. Most urban waterways contain sections with heavy weed growth, these areas provide a source of seed to colonize any disturbed downstream areas. Having a weed management and re-vegetation plan that extends up the catchment would be great, but of course also involves significant $$$</p> http://waterbydesign.com.au/forum/topic.php?id=362#post-617 Fri, 28 Oct 2011 17:19:37 +0000 BenniG 617@http://waterbydesign.com.au/forum/ <p>Hi all,</p> <p>Just doing some weekend googling on how others across Australia (or even the globe) look at a couple of issues in areas that are effected by cyclones and winters that might consist of 1 or 3 days a year.</p> <p>I'm working in WA's Pilbara region where your winter can be short as two days but&nbsp;you get 200-300mm of rain in one down pour.</p> <p>Anyone point me in the direction of examples of where other similar geographical locations deal with designing/using/maintaing large open swales with little to no rain for 99% of the year (and no spare potable water to irrigate) and/or options for capturing all that water and reusing?</p> <p>Thanks a heap</p> http://waterbydesign.com.au/forum/topic.php?id=361#post-616 Fri, 21 Oct 2011 20:06:05 +0000 Jack Mullaly 616@http://waterbydesign.com.au/forum/ <p>Hi,</p> <p>LCC has undertaken some work recently identifying the costs associated with maintaining WSUD systems. To date this has primarily this has focused on bioretention systems as they represent the majority of our assets. Regardless I would be very interested in discussing wetland maintenance costs, and seeing if some of the principles from each type of system can be applied to the other.</p> <p>Please feel free to contact me at: <a href="mailto:jackmullaly@logan.qld.gov.au">jackmullaly@logan.qld.gov.au</a></p> <p>Cheers</p> http://waterbydesign.com.au/forum/topic.php?id=361#post-615 Fri, 21 Oct 2011 12:39:39 +0000 parso 615@http://waterbydesign.com.au/forum/ <p>Hi, I am working with our maintenance staff to improve the way Constructed wetlands and the like are maintained. I am interested to know if anyone has costings for wetland veg maintenance? I am specifically talking about the process of manual weed removal of aquatic weeds, etc using bush regen principals. I understand it would be difficult to come up with a rate to cover all situation (weed density, area, access etc) however if anyone has had to develop a cost for budgeting purposes I would love to hear from you.</p> <p>Thanks.</p> http://waterbydesign.com.au/forum/topic.php?id=357#post-614 Thu, 20 Oct 2011 14:50:14 +0000 Dale 614@http://waterbydesign.com.au/forum/ <p>Hi Aleks.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Given your GPT will have no significant effect on flow rates (none modelled by MUSIC), you could simply apply the same high flow bypass to the GPT and the tank.</p> <p>For other treatment systems that do affect flow rates, there is a method to split flows. This is explained in Tips and tricks on the eWater website. It is also taught at the Advanced MUSIC training course.</p> <p>In terms of your treatment system design I presume that you are not reusing water for spray irrigation or any kind of indoor use including toilet flushing. The GPT will only reliably remove litter and some sediment as well as small amounts of nutrients. There may be a risk of the downstream system clogging given the limited sediment removal and the reuse water will contain other contaminants and pathogens given the limited treatment provided. For reuse systems it is advisable to adopt a multiple barrier approach incorporating additional treatment systems if possible, such as swales, rain gardens, and in some cases disinfection.</p> <p>Regards,</p> <p>Dale</p> http://waterbydesign.com.au/forum/topic.php?id=360#post-613 Thu, 20 Oct 2011 14:35:19 +0000 Tom 613@http://waterbydesign.com.au/forum/ <p>Hi,</p> <p>I'm wondering if there is any intention to update the list of suitable plants for use in WSUD systems, as the current version dates from 2006, and since then there has no doubt been significant experience gained as to which plants are more suited to the use (particularly in bioretention systems, which seem to be the dominant WSUD device out there). We have found that some of the species on the list are definately not suited to use, not only in WSUD systems but SE Qld humidity in general (i.e Lomandra Tanika, Lomandra Katrinus, Themeda Mingo). As this document is heavily referenced by councils and professionals it would greatly assist the industry if it was updated to ensure appropriate plants get used and to minimse plant failure.</p> <p>Thanks, Tom.</p> http://waterbydesign.com.au/forum/topic.php?id=357#post-610 Mon, 10 Oct 2011 09:20:18 +0000 Aleks 610@http://waterbydesign.com.au/forum/ <p>Hey All,</p> <p>Im working on some stormwater harvesting projects in Victoria and i am using MUSIC to test our own models and assumptions to harvest stormwater.</p> <p>The MUSIC model i have put together is such:&nbsp;</p> <p>Catchment -&gt; GPT -&gt; Hydrodynamic Separator -&gt; tank (with Demand)</p> <p>My issues are that the GPT and HS only have a treatable flow of 0.2 m3/s, this is the flow we need to meet our desired harvest volumes.</p> <p>My problem is that MUSIC cant split flows so the model is innaccurate in telling me how much rubbish is removed and how much &nbsp;volume we have harvested. eg:</p> <p>1m3/s comes down the catchment, i design the GPT and HS with a peak flow of 0.2m3/s, but MUSIC assumes that all the flow reaches the tank.</p> <p>Has anybody figured out a way to split flows in MUSIC or a method that can help my above problem?</p> <p>&nbsp;</p> <p>Aleks&nbsp;</p> <p>&nbsp;</p> http://waterbydesign.com.au/forum/topic.php?id=215#post-609 Wed, 05 Oct 2011 12:43:20 +0000 swilliams 609@http://waterbydesign.com.au/forum/ <p>Hi Alan</p> <p>Can you please advise when you will be publish the guideline for "Accepting Ownership of Vegetated Stormwater Assets&rdquo;</p> <p>Will this include the testing required for the Filter Media once material has been installed?</p> http://waterbydesign.com.au/forum/topic.php?id=215#post-608 Wed, 05 Oct 2011 12:41:17 +0000 swilliams 608@http://waterbydesign.com.au/forum/ <p>Riversands can supply Bioretention Filter Media that meets all of the primary requirements under the FAWB and Healthy&nbsp; Watereways Guidleines with Organics &gt;3%. They supply testing results to demonstrate the requirements of the guidelines and only produce to the latest specifications. The transistion layers and gravel layers can also be supplied.</p> <p>Phone 07 3287 6444</p> http://waterbydesign.com.au/forum/topic.php?id=215#post-607 Wed, 05 Oct 2011 12:34:57 +0000 swilliams 607@http://waterbydesign.com.au/forum/ <p>Riversands can supply Bioretention Filter Media that meets all of the primary requirements under the FAWB and Healthy&nbsp; Watereways Guidleines with Organics &gt;3%. They supply testing results to demonstrate the requirements of the guidelines and only produce to the latest specifications. The transistion layers and gravel layers can also be supplied.</p> <p>Phone 07 3287 6444</p> http://waterbydesign.com.au/forum/topic.php?id=355#post-606 Fri, 30 Sep 2011 15:17:20 +0000 Andrew O'Neill 606@http://waterbydesign.com.au/forum/ <p>Hi Katie,</p> <p>Further to Alan's response above, please see my 2 cents worth on this topic.</p> <p>The technology shows promise in certain situations as part of a holistic approach to sustainable water quality and quantity management. &nbsp;Published documents (see below) suggest that porous asphalt has a relatively high failure rate due to poor construction, construction phase sediment, and poor maintenance regimes.</p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <strong>MUSIC testing.</strong>&nbsp; With regard to modelling setup and assumptions, the <a href="../musicguide/">SEQ MUSIC Modelling Guidelines</a> deal with pervious pavement in Section 4.11.&nbsp; The guideline recommends using a media filtration node with no extended detention (see the Guideline for detailed assumptions).&nbsp; We set up a simple model that consisted of a 3m wide road with a 1m wide pervious strip (bike lane or similar) along the edge.&nbsp; When run with 1 yr of 6-min data (Brisbane) we found sediment load reductions in the range you suggested (~80%).</p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <strong>Soil.</strong> The underlying soil requires relatively high infiltration capacity. For example, the <a href="http://www.epa.gov/npdes/pubs/porouspa.pdf">USEPA fact sheet</a> suggests &gt;13 mm/h.&nbsp; In addition, infiltration into sodic or dispersive soils should be avoided.</p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <strong>Maintenance.</strong> Maintenance should also include vacuum sweeping and high pressure hosing 3-4 times per year which means that it might not be feasible in high traffic areas due to the inconvenience caused during maintenance.</p> <p>For these reasons, porous asphalt is a technology that probably has a place in the suite of technologies to manage urban water, but has potentially quite limited scope for implementation (due to traffic, clogging, maintenance issues).&nbsp; In addition, there may be some risks with some infiltration of partly treated stormwater into sensitive groundwater tables. &nbsp;Note that there is research currently being undertaken by researchers at <a href="http://www.watersensitivecities.org.au/?page_id=2827">Monash / Water Sensitive Cities</a> which may yield some answers to these questions and more local context to this discussion. &nbsp;I haven't contacted them about their progress but this could be a useful next step for you if you want to know where the science on this topic is at right now.</p> <p><strong>Some useful information sources:</strong></p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; USEPA<strong>: </strong><a href="http://www.epa.gov/npdes/pubs/porouspa.pdf">http://www.epa.gov/npdes/pubs/porouspa.pdf</a><strong></strong></p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Melbourne water<strong>: </strong><a href="http://wsud.melbournewater.com.au/content/treatment_measures/porous_paving.asp">http://wsud.melbournewater.com.au/content/treatment_measures/porous_paving.asp</a>)</p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Monash / Water sensitive cities research by Fern Yong with Ana Deletic and Tim Fletcher: <a href="http://www.watersensitivecities.org.au/?page_id=2827">http://www.watersensitivecities.org.au/?page_id=2827</a></p> <p>&middot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Western Australia Department of Water: <a href="http://www.water.wa.gov.au/PublicationStore/first/84987.pdf">http://www.water.wa.gov.au/PublicationStore/first/84987.pdf</a></p> <p>Hope that this is useful. &nbsp;Please do post back if this didn't answer your question and we can keep the discussion going.</p> <p>regards,</p> <p>Andrew</p> http://waterbydesign.com.au/forum/topic.php?id=355#post-605 Wed, 28 Sep 2011 11:42:22 +0000 alanhoban 605@http://waterbydesign.com.au/forum/ <p>Katie,</p> <p>I don't doubt that this would effectively capture sediment from minor runoff events. However because it cannot be cleaned out but rather needs to be replaced I&nbsp;have reservations about it's lifecycle cost compared to other ways of capturing coarse sediment (such as sediment forebays). On the other hand, if it is installed on road verges and would otherwise be replaced as part of routine road re-surfacing, perhaps the net additional cost required to deliver improved water quality outcomes isn't that much.</p> <p>Also, instances of high sediment loading-which are common with our poor erosion and sediment control practices-would greatly reduce the lifespan of the asphalt, so I think it's application would need to be limited to relatively low sediment situations.</p> <p>Alan</p> <p>&nbsp;</p> http://waterbydesign.com.au/forum/topic.php?id=307#post-604 Thu, 22 Sep 2011 09:25:51 +0000 Sarah Jones 604@http://waterbydesign.com.au/forum/ <p>Hi Kelly,&nbsp;</p> <p>I was unable to find a clear definition in relevant legislation or policy, so I sought clarification from the Water Quality and Accounting team in the Department of Environment and Resource Management who look after SPP 4/10. They have an email address for enquries about the policy&nbsp;<a href="mailto:spphealthywaters@derm.qld.gov.au">spphealthywaters@derm.qld.gov.au</a>, which I suggest your policy department seek a formal response from.&nbsp;</p> <p>Warm regards,&nbsp;</p> <p>Sarah Jones&nbsp;</p> <p>&nbsp;</p> http://waterbydesign.com.au/forum/topic.php?id=307#post-603 Wed, 21 Sep 2011 17:49:16 +0000 Kellaie 603@http://waterbydesign.com.au/forum/ <p>Hi Sarah,</p> <p>Thank you for the clarification. Would it be possible to let us know where the definition of the "dwelling" was taken from? We have add few questions from our policy department and we need to justify this statement.</p> <p>Many thanks.</p> <p>Kelly</p> http://waterbydesign.com.au/forum/topic.php?id=354#post-602 Wed, 21 Sep 2011 13:30:53 +0000 Tilake 602@http://waterbydesign.com.au/forum/ <p>Sorry about m2 I copied from a word document display differently.</p> http://waterbydesign.com.au/forum/topic.php?id=354#post-601 Wed, 21 Sep 2011 13:13:01 +0000 Tilake 601@http://waterbydesign.com.au/forum/ <p>Katie and Alan, thanks for your input.</p> <p>I agree with your suggestion that the best option is diversion.</p> <p>But, the question I am referring is basically to a development site having an external catchment where diversion is not generally practical or not preferred.</p> <p>If I put my question in a different way; for an example if we consider 1.0 ha of development (say 50% impervious), without any other devices (assumed for simplicity), a Bio-retention basin with a filter area of 200 m&lt;sup&gt;2&lt;/sup&gt; (surface area 250 m&lt;sup&gt;2&lt;/sup&gt;, filter depth 0.4 m, extended detention 0.3 m) will be required to achieve load reduction targets.</p> <p>Now, suppose we have an external catchment of 0.2 ha that flows into the basin mixing with the flow from the site.</p> <p>My question is &lsquo;what is the Bio-retention filter area required for the subject development..? Is it 200 m&lt;sup&gt;2&lt;/sup&gt; or more or less..?</p> <p>According to my thinking it cannot be more than 200 m&lt;sup&gt;2&lt;/sup&gt; as the development doesn&rsquo;t actually need to treat the external catchment. If that is correct, it should be 200 m&lt;sup&gt;2&lt;/sup&gt; or less.</p> <p>A filter area significantly less than 200 m&lt;sup&gt;2&lt;/sup&gt;&lt;sup&gt; &lt;/sup&gt;doesn&rsquo;t sound like good.</p> <p>However, I tried few trials with lesser areas and found that Bio-retention filter area of 140 m&lt;sup&gt;2&lt;/sup&gt; will satisfy the criteria indicated by Alan. When I checked the same area with Katie&rsquo;s second option, it indeed gave negative values as Katie mentioned. So, that method cannot be validated.</p> <p>I would appreciate more views.</p> <p>Tilake</p> http://waterbydesign.com.au/forum/topic.php?id=356#post-600 Tue, 20 Sep 2011 12:30:16 +0000 mmena 600@http://waterbydesign.com.au/forum/ <p>hello all, I'm looking for a simple conceptual model or diagram that shows the effect of several detention ponds in the output hydrograph of a basin. It must be nice and simply because it's for the city mayor to understand. Thanks a lot! Maria</p> http://waterbydesign.com.au/forum/topic.php?id=354#post-599 Mon, 19 Sep 2011 21:08:19 +0000 alanhoban 599@http://waterbydesign.com.au/forum/ <p>Katie, I think you're on the right track.</p> <p>You either need to manage the upstream catchment so that it does not enter your site's stormwater drainage and treatment systems.</p> <p>Or, if the upstream catchments enter your sites stormwater drainage and treatment systems, account for this runoff. Whilst it may be relatively 'clean' it will still affect the treatment performance of&nbsp;your treatment systems because treatment efficacy is related to pollutant concentrations, and you are also change the hydrologic performance of the systems.</p> <p>I'm not quite sure how you end up with negative&nbsp;pollutant loads???&nbsp; Can you explain the circumstances?</p> <p>Another approach to subtracting the upstream loads is to calculate the net load reduction you'd need to achieve the objectives on your site assuming it has no external catchment (in kg rather than as a % reduction). You can then model the whole system (upstream catchment + development site) and design your treatment measures to achieve this level of reduction.&nbsp;</p> <p>It is important when planning this that you understand the zoning of the upstream land and how it might be developed in the future as this may affect your strategy. For example if it is to be developed down the track, you'd want to avoid risks of sediment laden waters smothering your treatment measures and this may make you think more about a diversion option.</p> <p>Cheers Alan.</p> <p>&nbsp;&nbsp;&nbsp;</p> http://waterbydesign.com.au/forum/topic.php?id=311#post-598 Thu, 15 Sep 2011 13:57:02 +0000 Mike Wicks 598@http://waterbydesign.com.au/forum/ <p>Hi Marty, just wanted give an update that Stormwater360 performance data for TSS,TP &amp; TN was been published in accordance with the Music Modelling Guidelines&nbsp;on 14th September in AWA's water journal. It is currently only available in hardcopy but should be on the web shortly. For more info you can go to <a href="http://www.awa.asn.au">http://www.awa.asn.au</a>&nbsp;or contact Stormwater360.</p> <p>Regards,</p> <p>mike.</p> http://waterbydesign.com.au/forum/topic.php?id=354#post-597 Wed, 14 Sep 2011 09:32:32 +0000 katiefletcher 597@http://waterbydesign.com.au/forum/ <p>I've had this same issue several times and the answer has never been 100% clear.</p> <p>The problem is that with the current load-based reduction WQOs that if we are adding in a large external 'clean' catchment (often undisturbed bushland or similar) then it becomes nearly impossible to meet the objectives as you are trying to improve on a very clean inflow.</p> <p>We've had two suggestions to deal with this.&nbsp; Firstly, the obvious answer would be to divert the 'clean' external flows and keep in separate clean and dirty water systems.&nbsp; This will allow for you to treat your own water in isolation but requires additional earthworks and potentially will increase costs.</p> <p>Second option, where you can't separate, is to include the external catchment in your model but exclude the pollutants from your results (i.e. remove the load from the external catchment from both the input and output sides of your overall results and calculate the performance by hand). In this way the treatment measures are operating as they would which may be at a reduced capacity but you are excluding the load from the external catchment from your performance assessment.</p> <p>I'm keen to hear if anyone else has any thoughts on this second method and the validity.&nbsp; For some catchments this simply doesn't work as you end up with negative pollutant loads!&nbsp; Any other alternatives?</p> <p>Katie</p> http://waterbydesign.com.au/forum/topic.php?id=355#post-596 Wed, 14 Sep 2011 08:35:40 +0000 katiefletcher 596@http://waterbydesign.com.au/forum/ <p>Morning All</p> <p>We are currently reviewing some literature on the use of porous asphalt (specifically open graded asphalt) in highway or other conditions and the value as a water quality treatment measure.</p> <p>Tests undertaken in France the United States indicate that sediment load reductions of between 65% and 95% can be achieved simply through capture and storage of sediment in the voids of the pavement which are then removed via routine replacement of the asphalt at roughly 10 year intervals.</p> <p>This was something new to us and we had not heard of it's value as a treatment measure in Australian conditions but it clearly has the potential to greatly change the way we approach the treatment train and show improvement in the treatment performance above what is currently modelled in MUSIC through standard means.</p> <p>I'd appreciate any input from other WSUD people and the WBD design team as to whether this has previously been considered and if there have been any studies undertaken here.&nbsp; If so, could this be reasnoably modelled in MUSIC using a generic treatment node given a conservative estimate of the performance based on these prior studies and a calculated high-flow bypass based on pavement characteristics?</p> <p>Thanks all for your input!</p> <p>Katie</p> http://waterbydesign.com.au/forum/topic.php?id=350#post-595 Tue, 13 Sep 2011 10:51:50 +0000 Tilake 595@http://waterbydesign.com.au/forum/ <p>Dkoch</p> <p>The reason you are getting a low flow in split catchment is comparatively high ET loss in more pervious areas. The flow can be increased by adjusting the soil properties, but this may not be an appropriate way. You can also try reducing the impervious area rainfall threshold, but this will give only a little change. The only other way I see is to increase the impervious percentage (of nodes with pervious areas) to reflect more impervious percentage than the actual. If you have already used appropriate impervious percentages, Council&rsquo;s expectation is not a reasonable one.</p> <p>Tilake</p>