Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
DSpace
Fisher, Paul
Hu, Sabrina
Oh, John
This project aims to find out how to improve the health of Lost Lagoon and Beaver Lake in Stanley Park. Three aspects related to freshwater habitats which include water quality, stream invertebrates, and culverts are discussed. Water quality reflects the health of lakes directly by testing the chemical and physical parameters. Water temperature, pH, and nutrients level, for example, shows the measurable conditions of water quality. Stream invertebrate surveys, which assess invertebrate populations can be used to make inferences about long-term pollution levels and overall water quality have been conducted by SPES since 2018. Survey results were analysed in detail, looking for general patterns, and found a large portion of the survey results to be poor. The culvert system is used for both water movement and wildlife transportation in and out of the freshwater bodies. Outdated data on the culvert system was updated in this project allowing the exploration of possible approaches to improve the system and freshwater habitat conservation in Stanley Park. Over a span of eight months the team visited Stanley Park to collect water samples from Lost Lagoon and Beaver Lake, and collected data about culverts along trails and stream invertebrates. Based on the analysis of the data collected over this eight month span, and of data Stanley Park Ecology Society (SPES) collected since 2016, the freshwater habitat quality was found to be poor in both Beaver Lake and Lost Lagoon. Therefore, this project aims to give recommendations to SPES to improve the water conditions in Beaver Lake and Lost Lagoon. The data for water and culvert conditions in Stanley Park have been updated which benefits future research and helps to improve the freshwater habitats. Stream invertebrate surveys are an important part of the monitoring efforts, providing useful insight into water quality, but more survey locations should be added around beaver lake for a more thorough representation of the water quality entering Lost Lagoon. The current culvert system is in poor condition as about 40% of culverts are blocked by mud or debris, or the entrances or exits are buried underground. The culvert system needs to be restored and better maintained.
Recommendations to improve the large freshwater body ecosystems of Stanley Park based on water chemistry, stream invertebrates, and culvert data Paul Fisher, Sabrina Hu, and John Oh In partnership with the Stanley Park Ecology Society Department of Environmental Science, University of British Columbia ENVR 400 Student Capstone Project April 26, 2022 II Summary This project aims to find out how to improve the health of Lost Lagoon and Beaver Lake in Stanley Park. Three aspects related to freshwater habitats which include water quality, stream invertebrates, and culverts are discussed. Water quality reflects the health of lakes directly by testing the chemical and physical parameters. Water temperature, pH, and nutrients level, for example, shows the measurable conditions of water quality. Stream invertebrate surveys, which assess invertebrate populations can be used to make inferences about long-term pollution levels and overall water quality have been conducted by SPES since 2018. Survey results were analysed in detail, looking for general patterns, and found a large portion of the survey results to be poor. The culvert system is used for both water movement and wildlife transportation in and out of the freshwater bodies. Outdated data on the culvert system was updated in this project allowing the exploration of possible approaches to improve the system and freshwater habitat conservation in Stanley Park. Over a span of eight months the team visited Stanley Park to collect water samples from Lost Lagoon and Beaver Lake, and collected data about culverts along trails and stream invertebrates. Based on the analysis of the data collected over this eight month span, and of data Stanley Park Ecology Society (SPES) collected since 2016, the freshwater habitat quality was found to be poor in both Beaver Lake and Lost Lagoon. Therefore, this project aims to give recommendations to SPES to improve the water conditions in Beaver Lake and Lost Lagoon. The data for water and culvert conditions in Stanley Park have been updated which benefits future research and helps to improve the freshwater habitats. Stream invertebrate surveys are an important part of the monitoring efforts, providing useful insight into water quality, but more survey locations should be added around beaver lake for a more thorough representation of the water quality entering Lost Lagoon. The current culvert system is in poor condition as about 40% of culverts are blocked by mud or debris, or the entrances or exits are buried underground. The culvert system needs to be restored and better maintained. III Acknowledgments We gratefully acknowledge the Stanley Park Ecology Society and the ENVR 400 teaching teams for supporting us to research and study in Stanley Park. We are also thankful to Chris Payne who provided the water sample analysis. The team Paul Fisher Paul is a fourth-year undergraduate student in environmental science studying the land, air, water area of concentration. He has experience collecting water parameter data as well as stream invertebrate surveys. He is also knowledgeable about hydrology and water chemistry. Sabrina Hu Sabrina is a fourth-year undergraduate student majoring in Environmental Science. She is studying the land, air, and water concentration area. She has done a relevant water project in Deer Lake and is also familiar with the water measurement techniques. She has basic knowledge in using GIS software and R and is familiar with analysing data on Excel. John Oh John is a fourth-year undergraduate Environmental Science student studying in the concentration of Ecology and Conservation. With what he has learned in this concentration area, specifically conservation and restoration, he has gathered a plethora of skills that aided him in the success of this project. Skills would include remote sensing, experience in data analysis, and data collection. IV Table of contents 1. Introduction 1 1.1 Partner Organisation and Motivation for Project 1 1.2 Overview of Stanley Park 2 1.3 Water Quality 4 1.4 Stream invertebrates 5 1.5 Culverts 6 2. Research Objectives 7 3. Methods 7 3.1 Water Quality 8 3.1.1 In-situ measurements 8 3.1.2 Water sample collection 9 3.1.3 Assimilation of previous data 9 3.1.4 Data analysis 9 3.2 Stream invertebrate survey methods 10 3.2.1 Source data 10 3.2.2 Data analysis 12 3.3 Culverts 13 3.3.1 Culvert surveys 13 3.3.2 Data analysis 15 4 Results 18 4.1 Water quality 18 4.2 Stream invertebrates 26 4.3 Culverts 28 5. Discussion 30 5.1 Water quality 30 5.2 Stream Invertebrates 33 5.3 Culverts 35 6. Conclusions 37 7. Recommendations 38 8. References 39 Appendix 1: Water Quality 42 Appendix 2: Stream Invertebrates 43 Appendix 3: Culverts 44 Appendix 4: Project Process 57 V Table of figures Figure 1. Examples of the poor water quality in Lost Lagoon. 2 Figure 2. The locations of Beaver Lake and Lost Lagoon. 4 Figure 3. Water measurement locations in Lost Lagoon. 8 Figure 4. Water measurement locations in Beaver Lake 8 Figure 5. Stream invertebrate survey locations around Lost Lagoon. 11 Figure 6. Stream invertebrate survey locations around Beaver Lake. 11 Figure 7. Examples of the invertebrate taxa in each category of pollution tolerance. 12 Figure 8. Map of Stanley Park culverts. 14 Figure 9. Images of good and bad culverts. 16 Figure 10. Photos of the effects of blocked culverts. 17 Figure 11. Boxplot showing the summer water temperatures. 18 Figure 12. Average pH and DO (mg/L) of all survey locations 19 Figure 13. Phosphate and nitrite levels in Beaver Lake and Lost Lagoon. 20 Figure 14. Salinity in Beaver Lake boxplot. 22 Figure 15. Salinity in Lost Lagoon boxplot. 23 Figure 16. Salinity in Lost Lagoon through time. 23 Figure 17. Dissolved oxygen in Beaver Lake boxplot. 24 Figure 18. Dissolved oxygen in Lost Lagoon boxplot. 24 Figure 19. pH in Beaver Lake boxplot. 25 Figure 20. pH in Lost Lagoon boxplot. 25 Figure 21. Comparison of all stream invertebrate assessment categories. 26 Figure 22. Stream invertebrate survey seasonal comparison. 27 Figure 23. Spatial comparison of stream invertebrate surveys. 28 Figure 24. Percentage of culverts in each condition category. 29 Figure 25. Beaver lake culvert condition map. 29 Figure 26. Lost Lagoon culvert condition map. 30 Figure 27. Water temperature in Beaver Lake and Lost Lagoon over time. 42 Figure 28. Invertebrate survey results for each stream. 43 Figure 29. Seasonal comparison of invertebrate survey results. 43 Figure 30. Precedence diagram for the whole project. 57 Figure 31. Precedence diagram for the project proposal. 57 Figure 32. Precedence diagram for data collection and analysis. 58 Figure 33. Precedence diagram for literature search and final report. 58 Figure 34. Gantt chart of the predicted project timeline. 59 Table of tables Table 1. The criteria used to determine the condition of the culverts. 17 Table 2. Phosphate and nitrate in Beaver Lake. 25 Table 3. Phosphate and nitrate in Lost Lagoon. 25 Table 4. Measured and typical phosphate and nitrate levels. 42 Table 5. Condition and measurements of all surveyed culverts. 44 1 1. Introduction 1.1 Partner Organisation and Motivation for Project This project is in partnership with the Stanley Park Ecology Society (SPES), a registered charity since 1988. The organisation promotes awareness of and respect for the natural world through collaborative leadership in environmental education, research, and conservation in Stanley Park. For a sustainable development of the park, they identified the ecology knowledge gaps and designed monitoring and mapping programs to better understand the environmental changes in Stanley Park. They are also the primary land-based education interpretive services providers in Stanley Park. SPES provides educational events such as workshops, walks and webinars for all ages and abilities to learn about Stanley Park and the local ecosystem. This project aims to contribute towards its goal of maintaining and restoring Stanley Park’s ecosystems. Freshwater bodies are an essential ecosystem within the park. Protecting freshwater habitat is important for species conservation, migration planning, and environmental regulation (Bain et al., 1999). However, according to the 2020 State of the Park Report for the Ecological Integrity of Stanley Park (Comeau, 2020), the current status of their freshwater ecosystems is poor, with dissolved oxygen and water temperatures reaching unhealthy levels for wildlife in the park’s two largest freshwater bodies, Lost Lagoon (LL) and Beaver Lake (BL). Powerful illustrations of this are the recent massive die-off of carp in Lost Lagoon, the cause of which remains unknown, and the severe summer algae blooms (figure 1). It is urgent to understand the current state of the freshwater quality in more depth and find feasible solutions to improve the freshwater ecosystem in Stanley Park, thus preserving the aquatic life and their habitats, and the other aspects of the ecosystem that they support. This project aims to fill the gaps in knowledge of three aspects that relate the freshwater habitat quality in Stanley Park: water quality, stream invertebrates, and the culvert system. In particular, SPES currently has almost no up-to-date data on the culvert system, or the nutrients in Lost Lagoon and Beaver Lake. 2 Figure 1. Examples of the poor water quality in Lost Lagoon. Note the very high turbidity and presence of algae blooms indicating eutrophication. Photos were taken during summer by Peter Woods 1.2 Overview of Stanley Park Stanley Park is a large park next to Downtown Vancouver, which is mostly covered with coniferous forest of western hemlock, western redcedar, and Douglas-fir. The majority of the park’s perimeter is coastline, on all but the south side (figure 2). There is a small road along the perimeter of the park, as well as two small roads that cross the park. The Stanley Park Causeway (Highway 99) goes through the middle of the park, between Lost Lagoon and Beaver Lake and is one of only two roads connecting Vancouver to the North Shore, making it very busy. There is a vast network of trails throughout the park, most of which are gravel. These trails are raised to prevent them from flooding during winters, which disrupts the flow of water through the park. To mitigate this, a system of over 300 culverts has been installed to allow water to flow under the trails and roads. Lost Lagoon is an artificial lake that was once a tidal lagoon, sealed off from the ocean in 1916 when the Stanley Park Causeway was built (Worcester, 2010). Lost lagoon is situated between Downtown Vancouver and the rest of Stanley Park, so its southern and western edges are urbanised, with a golf course, tennis courts, and the city within 100 m of the concrete, south shore and natural west shore. The north side is bordered by forest, and a road just up a small hill from the rocky shore. Because of concerns of contaminants from vehicles on the Causeway entering the lagoon, a biofiltration pond is situated in its northeast corner. There are few aquatic plants in Lost Lagoon, but there are 3 substantial algae and cyanobacteria blooms in the summers (figure 1), contributing to fairly turbid waters all year long. Lost Lagoon is an important location for overwintering and breeding birds (Worcester, 2010). There are a number of small unnamed streams flowing into Lost Lagoon on its north side, and on its southwest side near the golf course, as well as Ceperley Creek, a very slow moving creek which drains a meadow on the West side of the lagoon. There is one outflow on the east side that flows through a pipe underneath the Causeway and into Coal Harbour. Beaver Lake is a natural wetland (Worcester, 2010), surrounded by forest on all sides and bordered by a gravel trail near or on its shore. The invasive fragrant water lily (Nymphaea odorata) is prolific in the lake, covering most of its surface in the summers. This has accelerated the rate of sedimentation in the lake, causing it to slowly get shallower, and contributing to eutrophication (Worcester, 2010). There are several small unnamed streams flowing into Beaver Lake, as well as North Creek, the largest inflow, on the northwest side, and Zoo creek on the east side. There is one outflow, Beaver Creek, on the northeast side, which drains through a concrete weir that maintains the lake’s water level and eventually into the ocean. A rough overview of the location of these streams can be seen in figure 2. 4 Figure 2. The locations of Beaver Lake and Lost Lagoon in Stanley Park, as well as the main inflows and outflows for Beaver Lake and Lost Lagoon. The Stanley Park Causeway is shown by the curved white line through the centre of the park (Comeau, 2020). 1.3 Water Quality One important indicator of freshwater habitat health is water quality. Water quality is the physical, chemical, and biological characteristics of water, which can be assessed by measuring these qualities or parameters (Ji, 2017). The most common water quality parameters measured include temperature, pH, nutrients level (ex. nitrate, nitrite, and phosphate), and dissolved oxygen (DO). Referring to British Columbia approved water quality guidelines, Stanley Park 2020 state report, and previous research (MacKinnon, 2018), basic water quality parameters such as temperature, pH, DO, phosphate, and nitrates were used in this project as indicators, as well as the N:P ratio. Many of these parameters are closely related to each other. For example, a high temperature can result in a low DO concentration in water as the solubility of oxygen decreases with temperature increase. 5 High pH in lakes usually occur more frequently and severely in waters with low total hardness (total concentrations of calcium and magnesium) thus moderating to high total alkalinity (capacity to neutralise acidity) (Wurts & Durborow, 1992). 1.4 Stream invertebrates Stream invertebrate surveys which analyse the invertebrate community diversity and structure, is a key component of evaluating the health of stream ecosystems and water quality (Marchant et al., 2006). It offers insight into the health of an ecosystem over a longer period of time than directly measuring physical or chemical variables, however, it does not provide information on the specific issues with water quality. Assessing the populations of species and community structure of stream invertebrates provides useful insight into freshwater quality and it is relatively easy to do. Some invertebrate taxa are more tolerant of poor water conditions such as pollution or low DO concentrations, while others are adapted to thrive only in very pristine environments. Therefore, if the tolerances of present taxa for poor water quality are known, the populations of these taxa or the invertebrate community makeup can be used to make inferences about the quality of the freshwater ecosystem (DFO, 1995; Marchant et al., 2006). For example, insects in the orders Ephemeroptera, Plecoptera, and Trichoptera (mayflies, stoneflies, and caddisflies, respectively) are particularly sensitive to pollutants, so their presence indicates very clean water (DFO, 1995). On the other hand, organisms in the order Oligochaeta (aquatic worms) or family Simuliidae (blackflies) are highly tolerant to pollutants, so their presence, and the absence of sensitive species indicate polluted water (DFO,1995). Since 2019, SPES has analysed stream invertebrates following the methods outlined in the streamkeepers handbook by the DFO (1995), which classifies organisms into three categories based on pollution tolerance. This assessment is very simple to conduct, making it excellent for routine bioassessments that can be conducted easily and quickly, and yields results that are easy to interpret. However, a consequence of this is that it is not particularly detailed or nuanced, classifying the water quality of survey sites as good, acceptable, marginal, or poor. Additionally, SPES has not analysed the broader patterns in the results of 6 past steam invertebrate surveys, instead looking mostly at the most recent or current results, and trends (Comeau, 2020). 1.5 Culverts Trails and roads present in the park have disrupted the natural movement of water and have generated a barrier effect restricting the movement of organisms and water (Yanes et al., 2011). Culverts have been used to help water pass through these obstacles, however traditional culverts possess flaws in their design. When culverts were first designed, they mainly addressed the limitation of water transportation with little consideration to wildlife usage (Eberhardt et al., 2011). A poorly designed and installed culvert can negatively affect wildlife passage and habitats (Culverts and Fish Passage, 2013). Organisms such as the red-backed salamander, rough-skinned newt, and the threespine stickleback (a native fish species), inhabit the park. Culverts in Stanley Park need to provide passage for these fish and amphibian species, not just water. Elements such as water velocity, elevated outlets, water depth, and debris and sediment accumulation are common causes of passage barriers and damage to habitats. High velocity occurs when the slope of the culvert is too high, when the width of the culvert is much narrower than the natural stream, or when the bed of a culvert is too smooth. This makes it difficult and exhausting for organisms to travel upstream or reside in the culvert, and promotes erosion and subsequent sedimentation. Erosion of the streambed can occur on the outlet of the culvert, especially when there is a drop at the end, which creates a pit in the streambed. Sedimentation, the settling of suspended particles, and the accumulation of debris can also occur during high water flows, especially just upstream of culverts that are not large enough or have a change of direction, causing water to slow down. When water in a stream slows down, sediments will fall out of suspension and accumulate at the area of reduced flow. Sedimentation may obstruct the culvert and cause damage to the habitat and hurt the food source of fish. British Columbia’s Ministry of Transportation and Infrastructure has created a guideline for proper culvert design and installation, which will be used as a reference when assessing the current state and condition of the culverts (Culverts and Fish Passage, 2013). 7 2. Research Objectives The primary objective of this report is to assess the freshwater quality in Stanley Park, and using this data, to suggest means for the Stanley Park Ecology Society (SPES) to improve the quality of the park’s freshwater habitat. To reach these objectives, the main research questions are outlined: 1. What will a detailed analysis of stream invertebrate survey data suggest about the overall long-term quality of the water? 2. What are the current and historical states of the water quality of Lost Lagoon and Beaver Lake? 3. What is the current state of the system of culverts surrounding Beaver Lake and Lost Lagoon? 4. How can the health of freshwater habitats in Lost Lagoon and Beaver Lake be improved? Answering these questions will allow better management of the ecosystem services that Stanley Park provides for people in Vancouver, such as its value as a recreational resource, as well as animals that reside in the park. 3. Methods In the methods section, approaches to assess water quality, culvert system condition, and stream invertebrate surveys in Lost Lagoon and Beaver Lake are explained in detail. Water quality testing was divided into two parts, the first part was in-situ measurements, using YSI probe to measure parameters. In the second part, water samples were collected in Lost Lagoon and Beaver Lake to analyse nutrients levels. For stream invertebrates, previous survey data was analysed. For the culvert system, the slope, size, and condition of culverts around Beaver Lake and Lost Lagoon were surveyed. After data collection, the current water quality of two lakes were analysed based on the water parameters and conditions of invertebrates and culvert system conditions. 8 3.1 Water Quality 3.1.1 In-situ measurements A YSI probe was used to measure water temperature, salinity, conductivity, dissolved oxygen, oxidation-reduction potential, pH, and air pressure. A YSI probe is a multiparameter metre which provides real time value of different parameters. The locations for measurements that SPES has historically used were also used for this report, which included 5 locations around Lost lagoon including one at the wood bridge over Ceperley Creek (figure 3), and 6 locations around Beaver Lake including one in Zoo Creek, and one in North Creek (figure 4). Figure 3. Locations of water measurements and sample collection in Lost Lagoon. Figure 4. Locations of water measurements and sample collection around Beaver Lake. 9 3.1.2 Water sample collection At all of the same locations as the YSI probe was used (figures 3 and 4), water samples were collected so that phosphate and nitrate concentrations could be analysed. Water was drawn into a large syringe, and a filter was placed on the nozzle. Water was then filtered into three 15 mL centrifuge vials for each sample location. If the filter became clogged before all three vials could be filled, it was replaced with a new one. Before filling the syringe at a new sample location, it was rinsed two to three times with the water at the new location to avoid dilution of samples and contamination between locations. A new syringe was used for each of Beaver Lake and Lost Lagoon. The filled vials were then sent to a lab for analysis. 3.1.3 Assimilation of previous data SPES has been collecting data on water quality fairly consistently on a monthly basis from most of the sampling locations since 2016 to 2018, depending on the location. This data included all the same parameters measured with the YSI probe. There was also some data from 2010 to 2012 that included the same parameters. However, this data was of limited use due to inconsistent sampling locations, and different naming conventions for the locations. The older data also had some measurements of phosphate and nitrates. Most of this data was spread out over multiple excel spreadsheets and needed to be organised. 3.1.4 Data analysis The data analysis included two parts. The first part was analysing the old data and new data from new surveys. All the targeted parameters such as pH, average DO, and salinity were plotted separately in scatter plots from 2016 to 2022. As stated before, the data from 2010 to 2012 could not be analysed with the newer data, so it was excluded from the analysis. Trend lines and R-square values were used to see if there were any significant trends over years. Phosphate and nitrates concentrations were analysed by Chris Payne at UBC. The nutrients level across the sampling locations in each lake were averaged and compared to values from similar streams and lakes. The N:P ratio of each lake was also calculated. If the ratio is larger than 16, the phenomenon of eutrophication is mostly controlled by the 10 concentration of phosphate (Weber & Deutsch, 2010). These parameters were also compared between sample locations within Beaver Lake and Lost Lagoon. To assess the water quality in Lost Lagoon and Beaver Lake, BC water quality guidelines ((British Columbia Approved Water Quality Guidelines : Aquatic Life, Wildlife & Agriculture : Summary Report, 2019) and other studies in Vancouver were used. A citizen science study assessed three types of watersheds including forested watersheds in Vancouver, which provides measurement results in phosphate, nitrate, pH, and so on (Shupe, 2017). For streams and lakes in this area, typical values for nitrates are between 0.31 (Shupe, 2017) and 0.432 ppm (Howell et al. 2014), and 0.03 ppm for phosphate (Howell et al. 2014; Shupe, 2017), and normal N:P ratios for similar creeks are between 20 and 40 (Hecky et al., 1993). 3.2 Stream invertebrate survey methods 3.2.1 Source data There is one surveyed stream relevant to Lost Lagoon, in Ceperley Creek, with two survey points, approximately 40 m apart, with the eastern point just beside the wooden bridge (figure 5). There are three surveyed streams relevant to Beaver Lake, all with two survey points (figure 6). Stream invertebrate surveys have been conducted by SPES consistently at all survey locations two times per year since the spring of 2019. There were also spring and fall surveys in 2014 and 2018 for Beaver Creek only. These surveys take place in the spring between mid-April and mid-June, and then again in the fall between late-September and early-October. 11 Figure 5. The stream invertebrate survey locations in Ceperley Creek which flows into Lost Lagoon, shown by CC-1 and CC-2. Part of the golf course can be seen on the south side of the map. Figure 6. The stream invertebrate survey locations in the streams that flow into and out of Beaver Lake, shown by NC-1 and NC-2 in North Creek, ZC-1 and ZC-2 in Zoo Creek, and BC-1 and BC-2 in Beaver Creek. Surveys are conducted following the methods in chapter 4 of The Streamkeepers Handbook (DFO, 1995), using one to three 30x30 cm quadrats, from which invertebrates are collected, sorted by taxa and then counted. There are three pollution tolerance categories 12 for invertebrates (figure 7). The number of taxa present, and number of individuals are counted in each of these categories, for each broad taxon. Figure 7. A few examples of the taxa in each category of pollution tolerance (DFO, 1995). 3.2.2 Data analysis With this population data of stream invertebrates, a pollution tolerance index, EPT (Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies)) index, EPT ratio, and the predominant taxon ratio are calculated using the methods from chapter 4 of The Streamkeepers Handbook (DFO, 1995). The latter three of these are measures of 13 diversity related to water quality, the foremost is a measure of pollution. From these indexes, ratings of poor, marginal, acceptable, and good are assigned; each also has a corresponding value of 1 to 4, respectively. These values are then averaged to give an overall rating for each survey, with ‘poor’ corresponding to 1-1.75; ‘marginal,’ 1.75-2.5; ‘acceptable,’ 2.5-3.25; and ‘good,’ 3.25-4. Counts of the ratings for each of these categories and the overall rating were then made to compare the results between years, streams, and seasons. The surveys from the two locations in each surveyed creek were treated as a single location due to their proximity. 3.3 Culverts 3.3.1 Culvert surveys Most of the culverts in Stanley Park were surveyed in 2008 to create a database of their coordinates. Some of these also had very brief descriptions of their condition and/or location. Only culverts that carried water towards Beaver Lake and Lost Lagoon were surveyed, as these would have the greatest effect on the freshwater habitat and water quality (figure 8). Measurements of slope, and diameter, or height and width of these culverts were taken. Photos of most of the culverts were taken and labelled using the number assigned to them from the 2008 surveys; the photos were also noted as the upstream or downstream end in the photos. Photos were only not taken if the culverts appeared to be in perfect working condition or missing. 14 Figure 8. Map of Stanley Park culverts. Red points represent surveyed culverts in this project, and grey points represent unsurveyed culverts. To measure slope, there were two methods used. For the first method, used for most culverts, a straight cut of wood, approximately 1 m long, and 2 cm wide and tall, was placed most of the way inside the culvert against its ceiling. Against the short end of the stick that was protruding from the culvert, an iPhone was placed, and the slope was measured using the measure phone application; this gave the angle to 1°. The second and more precise method that was used to measure culvert slope could only be used on culverts that satisfied all of the following conditions: 1) were not blocked so water could flow freely through, 2) there is little to no flow through the culvert, and 3) the culvert was either partially or completely submerged at both ends. These conditions ensured that the water’s surface could be used as a baseline to measure from. The total length of the culvert was measured, as well as the depth of the water inside the culvert (or the distance from the water surface to the top of the culvert if it was fully submerged). This allowed us to calculate the rise over run of the culvert, which could then be converted to degrees, yielding a much more precise measurement than the method using an iPhone. For some culverts, one end of the pipe was flared or tapered, if this was the case, measurements to the water surface were taken in an area of consistent diameter, as close to the end as possible. 15 For culverts that did not have any soil or gravel inside them, the inside diameter was measured using a ruler or measuring tape. For culverts that were partially filled with soil or gravel, the inside width, and inside height (from soil to top of culvert) were measured using the same implements. For culverts that had different sizes at each end, only the measurements of the smaller end were recorded, as this is what has a greater effect on flow rate and capacity. If one end of the culvert was less than half buried or filled, the diameter was also measured. Some culverts were found which were not surveyed in 2008 or labelled. Coordinates for these were recorded and a code was assigned. Notes were also taken on the culvert condition and added to the descriptions of the culverts from 2008. These could include whether or not the culvert was blocked, if one or both ends were buried, if there was water flowing through the culvert, if there was flooding or evidence of water flowing over the trail near a culvert, and anything else that seemed important or noteworthy. 3.3.2 Data analysis The condition of the culverts were divided into three levels: poor, fair, and good. There has not been a criteria made for culverts in non-fish bearing streams, therefore one has been made for this report using culvert designs recommended by the Government of British Columbia (Culverts and Fish Passage, 2013). Figure 9 depicts the difference between examples of a good and poor culvert. Culverts that were on the 2008 map, but are no longer present in 2022 were not given a rating. 16 Figure 9. Left: Image depicting a good culvert with good flow and no obstructions, and a small amount of gravel lining the bottom. Right: A culvert in poor condition that is completely blocked by mud and gravel, impeding water flow. Photos were taken in February 2022. The culvert condition scale has been based on five criteria (table 1): the surrounding of the culvert entrance and exit, the amount of erosion and sedimentation present, the slope and the presence of a perched outlet, amount of substrate inside the culvert, and the water flow. The entrance and exit must be clear so that water can flow in and out of the culvert. When large amounts of erosion is present the surrounding environment will start to degrade. Erosion occurs downstream when the flow velocity increases at a perched outlet. An example of erosion can be seen in figure 10. Therefore, the slope should be less than 3° to avoid increasing flow velocity and minimise substrate wash out and a drop off should be reduced. Substrates within culverts provide a passage for amphibians and other species. They also help reduce the water velocity by creating turbulence. Lastly, the water flow should not be impeded and should flow without obstruction. 17 Table 1. The criteria used to determine the condition of the culverts. The culvert is considered poor if it meets one or more of the criteria under that category. The culvert is considered fair or good if it meets all of the criteria under each respective category. This criteria was made for this project using information from the BC culvert design guidelines. Figure 10. Left: An example of water pooling on the upstream side of a blocked culvert. This culvert is on Bridle Path, north of Lost Lagoon in February, 2022. Right: An example of the trail erosion that can be caused by water flowing over the trail due to a blocked culvert. The gravel fills the drainage ditch, compromising its ability to carry water, forcing more water over the trail. This photo is on Hansen Trail, north of Beaver lake in January, 2022. 18 4 Results 4.1 Water quality Generally, there is no significant change in water quality parameters over the period that the data covers. The maximum summer water temperature has been assessed as too high in recent years by Comeau in the 2020 State of the Park Report, with maximum temperatures slightly higher in Lost Lagoon than in Beaver Lake. Summer was defined as the period for which the average daily high since 2007 is greater than 15°C, which is May 1 to September 30 (UBC ESB Rooftop Weather Summary, n.d.). Temperature from all available data within this period for both Lost Lagoon and Beaver Lake was analysed, with similar results to Comeau (2020), which can be seen in figure 11. The median water temperature in Lost lagoon for this period was 20.8°C, just below the threshold of 21°C that SPES uses for poor (too high), nearly 50% of data points in this period were too high. The water temperature in Beaver Lake was also high, with a median of 17.7°C, which is considered good by SPES, but almost 25% of data points were over 21°C. Figure 11. Boxplot showing the summer (May 1 to September 30) temperatures from all available data in Beaver Lake and Lost Lagoon. Outliers are shown by dots. The pH shows that the water in LL is more basic than BL (figure 12). Since the end of 2017, the pH of BL has become more variable and started to increase up to 10. The pH of BL is relatively more stable over time; however, it reached a very low value at 4.5 in 2018. The average DO shows a larger difference between BL and LL. In 2017, both lakes had average 19 DO around 8 mg/L, then started to diverge. LL has a higher level of DO, while the DO of BL has a decreasing trend. Figure 12. Average pH and DO (mg/L) of all survey locations in Lost Lagoon (blue) and Beaver Lake (orange) for each day that the data were collected since 2016. Linear trend lines and R squared values for both data sets were shown. DO stands for dissolved oxygen. From the box plot of nutrients (figure 13), it shows that both phosphate and nitrogen oxides are higher in BL. The nutrients level in BL is more variable across survey locations, up to 0.08 ppm for phosphate and 4.3 ppm for nitrate and nitrite. After comparing the nutrients data with other studies, the phosphate levels of BL and LL were found to be in the same range, but nitrate and nitrite levels are higher, especially for BL. BL has a lower pH while LL has higher one compared to Shupe’s 2017 study (Table 4, in appendix). 20 Figure 13. The comparison of phosphate (left), and nitrite (right) levels (ppm) between Beaver Lake (orange) and Lost Lagoon (blue). Note the different scales for the y-axis between the two graphs. Data was collected by UBC students in ENVR 400 in Stanley Park on March 2nd, 2022. In Beaver Lake, nitrate concentrations were slightly or much greater than the typical values for similar bodies of water of 0.31 to 0.43 ppm (Howell et al., 2014; Shupe, 2017), depending on location. At the outflow and Zoo Creek, it was only slightly greater, while at the west and east docks and the bog, nitrates were 2-4 times greater than normal. The outlier for nitrates was at the main inflow, North Creek, where it was 10-14 times higher than what is considered normal. The phosphate concentrations were, for the most part, in line with those from Shupe (2017) and Howell et al. (2014) of 0.29 to 0.30 ppm. Hecky et al. (1993) found the N:P ratio in temperate lakes to be between 20 and 40. All locations in Beaver Lake aside from Zoo Creek and the outflow had N:P ratios greater than this, particularly at North Creek (table 2). Values lower than this likely suggest nitrogen limitation, while values higher than this suggest an excess addition of nitrogen, and phosphorus limitation. The particularly high nitrate, N:P ratio and normal-low phosphate at North Creek suggest a substantial source of nitrate upstream that should be investigated. 21 Table 2. The phosphate and nitrate concentrations (ppm), and the nitrogen to phosphorus ratio (calculated using molarity) in Beaver Lake. Inflows are shown by the light blue rows. Only the data collected in March, 2022 is shown. Location PO4 (ppm) NO2 + NO3 (ppm) N:P North Creek 0.012 4.35 581.5 Outflow 0.080 0.79 12.9 West dock 0.029 1.20 66.5 East dock 0.026 1.48 89.9 Bog 0.040 1.01 40.3 Zoo creek 0.026 0.56 34.8 Both the nitrate and phosphate concentrations at the inflows of Lost lagoon are similar to or higher than those from Shupe (2017) and Howell et al. (2014), which can be seen in table 3. The same is true for the N:P ratio at the inflows compared to Hecky et al. (1993). The main body of Lost Lagoon, however, has slightly low phosphate, and extremely low nitrate and N:P ratios. This suggests that the nitrate that exists at the Ceperley Creek inflow is almost completely used up, probably by algae and cyanobacteria by the time it reaches the eastern half of the lagoon. The stone bridge, the area with high nitrate in Lost Lagoon is very close to the golf course, which may be a potential source of the nitrogen that contributes to eutrophication, if fertilisers are used to maintain the lawn. An additional, likely significant source of nutrients for both Lost Lagoon and Beaver Lake is birds. Both bodies of water are important for birds (Worcester, 2010), and the grass fields in and around Stanley Park are often covered with lots of faeces from geese. The nutrients from this can be carried into streams, and subsequently Beaver Lake and Lost Lagoon by rainwater. Table 3. The phosphate and nitrate concentrations (ppm), and the nitrogen to phosphorus ratio (calculated using molarity) in Lost Lagoon. Inflows are shown by the light blue rows. Only the data collected in March 2022 is shown. Location PO4 (ppm) NO2 + NO3 (ppm) N:P Ceperley Creek 0.042 0.693 26.6 Stone bridge 0.039 1.32 54.6 North side 0.013 0.027 3.4 South side 0.012 0.045 5.8 Outflow 0.012 0.033 4.4 22 There was no obvious spatial pattern in the salinity for Beaver Lake for all of the data that was collected since 2017 (figure 14). Lost Lagoon on the other hand had an obvious spatial pattern in salinity from all of the data (figure 15). In general, the sample locations farther from the ocean (or the outflow) had the lowest salinity. This suggests that there is some source of salt on the east side of Lost Lagoon. One possibility of this source is the ocean which could indicate a problem with a mechanism that prevents seawater from flowing into Lost Lagoon through its outflow. Another possible source is road salt from the Stanley Park Causeway and concrete walking paths on the east side of Lost Lagoon. No obvious seasonal pattern in the salinity was found, which would be expected if the source of salt was road salt which is used in winter months. This makes the latter possibility seem less likely, however, there are gaps in data during many winters, which may hide seasonal trends. It is important to further investigate this source of salt, as it has been increasing since 2017 (figure 16). Figure 14. Boxplot shows the salinity (ppm) at each of the sampling locations in Beaver Lake from 2017 to 2022. Outliers are shown by dots. 23 Figure 15. Boxplot shows the salinity (ppm) at each of the sampling locations in Lost Lagoon from 2017 to 2022. Outliers are shown by dots. Figure 16. Scatterplot shows the salinity at the outflow (orange), north side (yellow), and south side (green) sampling locations in Lost Lagoon. A linear trend line is fitted to each data series. The dissolved oxygen in Beaver Lake is greatest at the main inflow (North creek), and second highest in the bog, which is also an inflow, but is broad and is not confined to a single stream. The DO is generally much lower at the east and west docks and the outflow of Beaver Lake, and is quite similar between these three locations (figure 17). This is likely due to the relative lack of organic matter from algae (i.e. eutrophication is not occurring yet) in the inflows. Organic matter increases the oxygen demand, causing oxygen to be consumed 24 as it decomposes. The main body of beaver lake shows signs of eutrophication (Worcester, 2010), meaning it has excessive primary productivity, and therefore excessive organic matter which must decompose. Since the decomposition of this organic matter consumes oxygen, it makes sense that the DO in the main body of Beaver Lake is lower. The DO in Lost Lagoon is more similar throughout, but is generally slightly higher in the main body of the lake (north side, south side, and outflow), than at the inflow (Ceperley Creek and the stone bridge), which can be seen in figure 18. Lost Lagoon is also eutrophic (Comeau, 2020; Worcester, 2010), which explains the low DO throughout. Figure 17. Boxplot shows the DO (ppm) at each of the sampling locations in Beaver Lake from 2017 to 2022. Outliers are shown by dots. Figure 18. Boxplot shows the DO (ppm) at each of the sampling locations in Lost Lagoon from 2017 to 2022. Outliers are shown by dots. 25 The pH was similar throughout for each body of water. In Beaver Lake the pH was slightly higher at North Creek and the bog (figure 19). The opposite was true in Lost Lagoon, where the inflow (Ceperley Creek and under the stone bridge) had slightly a greater pH, overall (figure 20). Figure 19. Boxplot shows the pH at each of the sampling locations in Beaver Lake from 2017 to 2022. Outliers are shown by dots. Figure 20. Boxplot shows the pH at each of the sampling locations in Lost Lagoon from 2017 to 2022. 26 4.2 Stream invertebrates After the analysis of all survey locations over the total period, including 2014 and 2018 to 2021, the overall rating was not good (figure 21). The majority of surveys across both bodies of water reported poor or marginal with 41.5% being rated as poor, and 38% being rated as marginal. Only 13% and 8% of surveys reported ratings of acceptable and good, respectively. EPT surveys were similar, with more than 55% and 70% of surveys assessing the EPT index and ratio, respectively, as poor, and less than 10% of surveys reporting both categories as good. The Pollution Tolerance Index was slightly better, with only 21% of surveys assessing this category as poor. However, this category could be better, as only 21% of surveys assessed it as good. The category which had the best ratings was the Predominant Taxon Ratio with most assessments as good (20%) and acceptable (46%), meaning for most surveys, the predominant taxon made up less than 60% of the individuals, or that communities were relatively diverse, regardless of the pollution tolerance. Figure 21. Comparison of all assessments. The proportion of stream invertebrate surveys results in each category for all surveys. The overall column is the average rating from the four other columns The categories, Poor, marginal, acceptable, and good results are shown by progressively lighter colours, respectively. 27 Overall, ratings from stream invertebrate surveys were better in the spring than in the fall; this was true for all categories except the predominant taxon ratio, for which ratings were slightly better in the fall. The overall ratings were particularly bad in the fall surveys, with 48% of surveys assessing this category as poor, 37% as marginal, and only 4% as good (figure 22A). The pollution tolerance index ratings were similar, but not as bad, both with less than 25% of assessments as poor, and 38% and 37% of assessments being acceptable and good for the spring and fall, respectively (figure 22B). Figure 22. Seasonal comparisons. The proportion of stream invertebrate survey results in each category for all surveys in the fall (left columns, and spring (right columns). The overall assessments are shown by (A), the pollution tolerance assessments are shown by (B). The survey location which had the best ratings was Zoo Creek, an inflow to Beaver Lake. In this location, 20%, 40%, 30% and 10% of surveys had overall ratings of good, acceptable, marginal, and poor, respectively (figure 23A). Beaver Creek, Beaver Lake’s outflow, and Ceperley Creek, Lost Lagoon’s nearly stagnant inflow had the worst overall ratings. The pollution tolerance index followed a similar pattern, with the best assessment results in Zoo Creek, where 20%, 20% and 60% of survey assessments were marginal, acceptable, and good, respectively, and no survey assessments were poor (figure 23B). 28 Beaver Creek had the worst ratings, where 35%, 55%, 5%, and 5% of surveys were poor, marginal, acceptable, and good, respectively. Refer to figures 5 and 6. Figure 23. The proportion of stream invertebrate survey results in each category for all surveys in each of the surveyed creeks, Ceperley Creek (CC), Beaver Creek (BC), Zoo Creek (ZC), and North Creek (NC). The overall assessments are shown by (A), the pollution tolerance assessments are shown by (B). 4.3 Culverts After the culvert data analysis, the condition of the culvert has been determined to be poor in general. In total, ninety-four culverts were surveyed and 39 (41.5%) were rated poor, 36 (38.3%) were rated fair, and 19 (20.2%) were rated good (figure 24). In Beaver Lake, 25 culverts were surveyed. Out of the 25, 56% were given a poor rating and only three culverts were in good condition. In Lost Lagoon, a total of 69 culverts were surveyed. The largest proportion of culverts were rated as fair, 40.6%, but still a significant amount was rated poor, 36.2%. However, compared to Beaver Lake, Lost Lagoon has a much greater proportion of good culverts with a percentage of 23.2%. In general, most of the blocked culverts were smaller culverts near gravel trails (figures 10). Most of the culverts that were poorly constructed were larger and placed on streams. Figures 25 and 26 show the locations of surveyed culverts and their condition around Beaver Lake and Lost Lagoon, respectively. 29 Figure 24. The percentage of poor (red), fair (yellow), and good (blue) culverts in Beaver Lake and Lost Lagoon. Only the culverts that flow into the lake or lagoon were surveyed. Beaver Lake has 25 culverts and Lost Lagoon has 69 culverts for a total of 94. The culvert data was collected during February to March of 2022. Figure 25. A map of the surveyed culverts surrounding Beaver Lake. Labels indicate the culvert number while the colour visually depicts their condition; the legend shows the relationship between the colour and condition of the culvert. The culvert data was collected during February to March of 2022. 30 Figure 26. A map of the surveyed culverts surrounding Lost Lagoon. The colour visually depicts their condition; the legend shows the relationship between the colour and condition of the culvert. The culvert data was collected during February to March of 2022. 5. Discussion 5.1 Water quality The thresholds of water temperature, pH, and DO were established in the Stanley Park State of the Park report in 2020 (Comeau, 2020). The critical water temperature was set at 21°C, if the maximum summer water temperature exceeds this threshold it will be considered poor. In 2016, the recorded water temperature in both LL and BL was under 21°C. However, since 2017, the yearly maximum temperature has exceeded 21 °C. The water temperature in LL reached the highest at 29.3 °C in 2018, and 26.2 °C in BL in 2020. The increase in water temperature is likely due to several reasons. The first is the shallow water depth in both Beaver Lake and Lost Lagoon, which is at most between 1.5 and 2 m (Worcester, 2010). Shallow lakes are generally closely tied to the air temperature due to a high surface area to volume ratio, allowing them to heat up with the air and solar radiation quickly (Johnson et al., 2014). The rapid infilling of Beaver Lake (Comeau, 2020) will exacerbate this problem in the future. Another reason for the high water temperatures is 31 the high turbidity of the water in both bodies, particularly Lost Lagoon. More turbid water does not allow sunlight to penetrate as deep, so incoming solar radiation is absorbed by the shallower surface layer, which heats up quickly, rather than being absorbed by the entire water column. Considering the increasing frequency of extreme weather appearing these years, more extreme maximum water temperatures are expected in both lakes. To decrease the water temperature, increase vegetation shading helps to reduce the solar insolation (Null & Elmore, 2017). The temperature in Lost Lagoon is likely greater than in Beaver lake for three main reasons. The first is the turbidity of the water; Lost lagoon is more turbid than Beaver lake, particularly in the summer when algae blooms are present. The second is the proliferation of fragrant water lilies in Beaver Lake (Worcester, 2010) which covers most of the surface during summers, shading the water column from solar radiation. The third is related to the amount of trees which shade the lakes. Beaver Lake is surrounded by conifers on all sides, whereas Lost Lagoon is only forested on the north side. The tall conifers cast large shadows on the lakes, and Lost Lagoon receives very little of this shade in the summer. According to the SPES state report, if the minimum DO in summer is lower than 6 mg/L, then it is considered poor. From figure 11, more than half of the data from BL was lower than 5 mg/L, while in LL most of the data points were higher than 8 mg/L. For all life stages of animals other than buried embryo or alevin, the instantaneous minimum DO in the water column is suggested to be above 5 mg/L (British Columbia Approved Water Quality Guidelines : Aquatic Life, Wildlife & Agriculture : Summary Report, 2019). However, for a long-term scale, the DO level should be higher than 8 mg/L. The DO level in BL was mostly lower than this, so hypoxic conditions for fish species and other aquatic organisms existed. From figure 16, the DO level was much lower in three locations, indicating the existence of dead zones in BL where hypoxia is more likely to happen (Kirchman & UPSO eCollections, 2021). Fish may tolerate hypoxia but with increased stress, reducing fitness, which could result in the reduction of fish populations in BL. The water quality is considered poor if the pH is too acidic or too basic. Since late 2019, the maximum pH in LL was consistently basic, exceeding 9. The pH of BL varies, but was fairly acidic in 2018 with the pH measured below 5. High pH is one of the main parameters that cause the dominance of the phytoplankton community by cyanobacteria 32 (Lund, 1965; King, 1970; Hutchinson, 1967; Brock, 1973). The massive algae blooms in LL in summers may partially be due to the high pH. To bring the pH in both lakes back to normal range, one approach is to adjust the wetland ecosystems. According to the post-restoration monitoring of water quality in Pashan Lake in South Africa, changes in bird diversity greatly affected the chemical conditions related to pH (Yardi et al., 2019). However, the potential disturbance brought by invasive species is a concern, so native plants are preferable. Therefore, more safe approaches and further research on pH restoration needs to be done. As introduced before, high alkalinity is tightly related to high total hardness. To lower the pH in LL, reducing the source of calcium and magnesium is important. The natural sources of alkalinity usually come from rock and land surrounding the lake, so controlling the erosion of the soil and rocks around the lake helps to solve the issue. The acceptable range of total phosphorus levels is from 0.005 to 0.015 ppm (Yardi et al., 2019). Based on the nutrients analysis results, 7 out of 11 sample locations in both LL and BL had a higher phosphate concentration. In terms of nitrates, the long-term average range of concentration to protect aquatic wildlife is between 3 and 32.8 ppm (Nordin & Pommen, 2001). However, only one sample from BL was in this range. Similar studies done in Lake Huron and Vancouver wetland watersheds revealed similar nutrient levels (Shupe, 2017; Howell, et al., 2014). Due to the limitation of nutrients data, the analysis results can only be treated as a single datapoint, and not extrapolated to other times of the year. Because the nutrients levels in a waterbody have spatial and temporal variability (Shupe, 2017), the water samples collected for this report may not be a good representation of the normal conditions in Beaver Lake and Lost Lagoon. The long-term water quality cannot be defined as poor or good based on the limited data. To improve the water quality, consistent long-term nutrients monitoring is needed to provide more useful information for effective management. The very high nitrates found in North Creek are a particularly important metric to investigate further, as this could be a significant source of the eutrophication in Beaver Lake, if it is this routinely higher than other locations. The cause for the high concentration of nitrates at this location could not be determined as there is no obvious source upstream. 33 5.2 Stream Invertebrates The spring and fall stream invertebrate surveys give a good insight into the water quality of the streams leading into Beaver Lake, and in Beaver Lake via surveys in Beaver Creek, its outflow. Due to the time-integrated results of stream invertebrate surveys (Marchant et al., 2006), the spring and fall survey times are sufficient to monitor the invertebrate communities and make inferences on the water quality. The timing of the spring survey allows insight into the water quality over the winter, and the timing of the fall survey allows insight into the water quality over the summer. The fall survey is particularly important because of the tendency for algae blooms to occur in the summer months (figure 1), particularly in Lost Lagoon (MacKinnon, 2018). The tendency for worse overall and pollution assessments in the fall compared to the spring may be due to the summer algae blooms, the temperature, precipitation, or some other factor. This possibility could be explored with more information on the physical parameters of water and nutrient concentrations gathered through future monitoring. The mid-April to mid-June spring survey occurs at the end of a long period of consistent rainfall and cooler temperatures, just before average daily highs exceed 20°C (UBC ESB Rooftop Weather Summary, n.d.). The late-September to early-October fall surveys occur at the end of the dry period in the summer, just after the onset of fall rains, and at the end of elevated temperatures (UBC ESB Rooftop Weather Summary, n.d.). The warmer temperatures, as well as greater availability of sunlight prior to the fall surveys may promote the summer algae blooms, which in turn may cause the worsened stream invertebrate survey scores. However, this likely would not be the case in the surveys from Beaver Lake’s inflows as these tend to have water with lower turbidity, indicating lower concentrations of algae. The nitrate concentration was found to be high in the inflows for BL and LL, which is a potential source of the nutrients causing eutrophication. The precipitation and temperature may play a greater role in the observed seasonal discrepancy. The low precipitation in the summers, prior to the fall survey, caused lower flow and water levels in the surveyed creeks which may allow pollutants to become more concentrated in the smaller volume of water, as well as stagnant water due to less flushing. The three survey locations relevant to Beaver Lake which include two inflows and the outflow allow inference to be made on where water quality issues may be originating 34 from. For example, the slightly better assessments in Zoo Creek compared to North Creek indicate that North Creek may be a greater contributor to the poor water quality in Beaver Lake, especially considering that it is a much larger input of water than Zoo Creek. The surveys at the outflow of Beaver Lake in Beaver Creek can be compared to the results from inflow surveys. The worse assessment scores in the outflow compared to the inflow indicate that something is happening in Beaver Lake, not upstream of it, to reduce the water quality, which affects the stream invertebrate community downstream. This sort of comparison cannot be made for Lost Lagoon, as there is only one surveyed creek, Ceperley Creek, which is an inflow. It would be impossible to conduct stream invertebrate surveys in the outflow of Lost lagoon because the outflow is immediately directed underground and into the ocean. However, useful information could be found from surveying more creeks flowing into Lost Lagoon, which could be compared to the surveys in Ceperley Creek, and could give insight into where Lost Lagoon’s pollution may be coming from. There is an ephemeral stream on the southwest side of lost lagoon (MacKinnon, 2018) which carries water that flowed over the Stanley Park Pitch and Putt Course which could yield informative invertebrate surveys in the spring, though may not be flowing sufficiently in the fall. Golf courses require chemicals to maintain a high-quality lawn for a good playing surface, the effects of which may be detectable through the invertebrate population in this stream. There are also two streams that were observed to have similar flows to Zoo Creek in February 2022 north of Lost Lagoon that flow into long culverts to cross underneath North Lagoon Drive close to the west end of Lost Lagoon. Stream invertebrate surveys conducted in one or both of these creeks could also provide useful information on the water quality flowing into Lost Lagoon, however, these creeks may be ephemeral, only persisting during rainy periods. Regardless, they could at least provide useful insight during the spring surveys. Because measurements taken with the YSI probe do not include nutrients or other pollutants, it is difficult to get a sense of the pollutants present that affect the stream invertebrate populations and surveys. This is one of the weaknesses of stream invertebrate surveys, they just show the symptoms of pollution in an invertebrate population, not the causes. With more consistent sampling of nutrients in streams, particularly in North Creek and Beaver Creek (or the outflow of Beaver Lake), and in Ceperley Creek, it is possible that a 35 relationship could be found between nutrient levels and the results from future stream invertebrate surveys. Inorganic pollutants from the vehicles on the Stanley Park Causeway that enter the streams could also influence the stream invertebrate survey results, and the water quality in Lost Lagoon and Beaver Lake, but there is very little data on the concentration of these. The biofiltration pond was built in Lost Lagoon to reduce the pollutants entering the main body, as the Causeway is very close to the lagoon with little vegetation separating the two (Worcester, 2010). Beaver Lake is much farther from the causeway, with plenty of forest to absorb pollutants before most of the water reaches the lake, however, North Creek flows directly under the Causeway (see figure 2) north of Beaver Lake, potentially allowing pollutants to enter Beaver Lake through North Creek. This, combined with the relatively poor stream invertebrate survey ratings (figure 22) are cause for further investigation into the inorganic pollutants entering Beaver Lake through North Creek. 5.3 Culverts Since 2008, when the culverts were last surveyed, there does not appear to have been any significant improvements to the culvert system. Many culverts surrounding Beaver Lake and Lost Lagoon are in need of replacement or repair to restore their functionality. Figures 24, 25, and 26 depicts the current overall quality of the culvert system. Even though the culverts at Lost Lagoon are proportionally better than the culverts at Beaver Lake both areas could be improved. Most of the poor culverts in both areas are blocked by mud or debris, or the entrances or exits are buried underground. Some culverts were found to be physically damaged from fallen rocks, branches, or rusting. Flooding was also observed on the upstream side of the trail where culverts were severely blocked. This would cause pools of water to overflow and run over the trail, causing erosion. Erosion was also visible in some of the poor culverts. Culvert #75 currently shows the most severe case of erosion seen through the surveyed culverts. The downstream end has an elevated outlet along with a high water exit velocity, causing degradation to the surrounding environment. A sharp turn is present right in front of the culvert outlet, heightening the effects of erosion underneath an 36 adjacent tree’s root mass. Figure 10 also shows areas of erosion seen around the trails. Restoration work should be conducted as soon as possible to minimise the impact of erosion on the site and adjacent ecosystems (Culverts and Fish Passage, 2013). The material of the culvert does not seem to have a large impact on the water flow, though plastic culverts with no gravel inside likely had higher flow rates. Additionally, corrugated metal culverts appear to collect gravel along the bottom better than those with smooth interiors, which reduces flow rates. There was a mix of plastic, metal, and concrete culverts around Lost Lagoon and Beaver Lake. All three types of materials had culverts in all three condition ratings. This shows that they can all be used in an effective way in different scenarios. Properly maintaining these culverts seem to play a greater role in keeping them functioning efficiently. For this report, the diameter of the culvert and its significance could not be analysed. It is recommended that the diameter or width of the culvert is similar to the natural stream size (Culverts and Fish Passage, 2013). This is to reduce disturbances to the stream's natural flow rate. With more data collection and analysis, it would be possible to determine the relationship between water flow and culvert size. Further research is necessary to fully understand the impact that the culvert system has on the fresh water bodies. With the current data, there does not seem to be any spatial relationship between the condition of the culverts and water quality. However, due to the poor condition of the current culvert system it is difficult to conduct reliable and accurate research on the relationship between the culvert system and the water quality of the freshwater bodies. Therefore, it is recommended that the poor culverts are restored, cleaned, and maintained to improve the water and organism passage of both freshwater bodies. The fair culverts should be occasionally inspected to see if their condition has deteriorated. The good culverts should also be inspected but do not need to be as often as the fair culverts. It is also recommended that the other culverts around the park are surveyed. 37 6. Conclusions The current state of water quality in Lost Lagoon and Beaver Lake is poor. The DO in BL was below the safe value, while LL had a pH above the safe value. The high pH and water temperature in summer possibly contributed to the high carp mortality in the fall of 2021. Compared to Shupe’s study (2017), the average nutrient levels of both lakes are in the normal range, but show some extreme values on a finer spatial scale. Considering the water quality guidelines for aquatic wildlife protection in BC, both lakes have poor nutrient conditions. The stream invertebrate surveys provide an important piece of information for the long-term water quality in the surveyed streams. These surveys should be continued on the current schedule, as the spring and fall surveys provide adequate coverage of the time between surveys. The survey locations relevant to Beaver Lake provide enough insight into water quality by including surveys in most of the major inflows and outflows of Beaver Lake. There is, however, a lack of survey coverage for Lost Lagoon. A survey in the outflow would be impossible, but adding a survey location to the ephemeral creek on the southwest side and/or the creeks on the north (figure 2) side that flow under North Lagoon Drive would provide useful information. This will be an efficient and cost-effective way to increase the coverage of water quality data, as these stream invertebrate surveys take only one to two days to complete, and require few instruments or equipment (DFO, 1995). These could be conducted by volunteers, like the current stream invertebrate surveys, and with the existing equipment, therefore, adding little to no additional cost. The current state of many culverts around Lost Lagoon and Beaver Lake are poor. More than half of the culverts surveyed in Beaver Lake are rated as poor and only three out of 25 have been rated as good. In Lost Lagoon, 36.2% of the surveyed culverts have been rated poor, 40.6% as fair, and 23.2% as good. Further research is necessary to fully understand the impact that the culvert system has on the freshwater bodies. In its current condition there could be potential impacts on Lost Lagoon and Beaver Lake such as greater trail erosion and complete blockage of all culverts. 38 7. Recommendations Below are recommendations for improving the water quality in both lakes: 1. For the future protection of freshwater habitats, more nutrients level tests are recommended. By observing the differences in nutrients levels at different sample locations in each lake, the sources of contamination can be better understood. 2. Utilise the spatial differences of nutrients level to trace the contamination sources. Ceperley Creek and Stone bridge in Lost Lagoon, North Creek, Bog, and Zoo Creek in Beaver Lake are recommended to be considered. 3. To decrease the water temperature in summer, planting more vegetation around Lost Lagoon, particularly on the concrete south shore helps to provide more shade that reduces the solar radiation, thus cooling the surface water in extreme weather. 4. Artificial floating islands (AFIs) are recommended in Lost Lagoon. AFIs have four functions in aquatic environments, including water purification, habitat enhancement, shoreline erosion protection, and improved landscape features (Mueller & Nakamura, 2008). Increase in aquatic plant species from AFIs helps to enhance the nutrient absorption, especially nitrogen, which can reduce the phytoplankton production and eutrophication. AFI also benefits aquatic life such as juvenile fish as it provides important shade for them to avoid high temperatures in summer. Below are general recommendations for culverts: 1. Restoration work should be prioritised to minimise the impact of erosion. For example, culverts 72, 75, and other poor culverts seen in figure 24 and 25. Broken culverts should be replaced while clogged culverts should be cleared. Culvert details are indicated in the Appendix (table 5). 2. Occasional inspections should be carried out to maintain the condition of the fair and good culverts. 3. Support further research that investigates the relationship between the culvert system and the water quality of the freshwater bodies. 4. Survey the rest of the culverts. 39 8. References Bain, M. B., Hughes, T. C., & Arend, K. K. (1999). Trends in Methods for Assessing Freshwater Habitats. Fisheries, 24(4), 16–21. https://doi.org/10.1577/1548-8446(1999)024<0016:TIMFAF>2.0.CO;2 British Columbia. Water Protection and Sustainability Branch, British Columbia. Ministry of Environment and Climate Change Strategy, & British Columbia Government EBook Collection. (2019). British columbia approved water quality guidelines: Aquatic life, wildlife & agriculture : Summary report. Ministry of Environment and Climate Change Strategy. Brock, T. D. 1973. Lower pH limit for the existence of blue-green algae: Evolutionary and ecological implications. Science, 179: 480-483. Comeau, A. (2020). State of the Park Report for the Ecological Integrity of Stanley Park. Stanley Park Ecology Society. https://stanleyparkecology.ca/wp-content/uploads/2021/07/SOPEI_Full_Oct2020.pdf Culverts and Fish Passage. (2013). BC Ministry of Transportation and Infrastructure. https://www2.gov.bc.ca/assets/gov/driving-and-transportation/transportationinfrastructure/engineering-standards-andguidelines/environment/references/3824_culvertfishpassage_infosheet.pdf?fbclid=IwAR3NK9lkD0z0E1ffC8U2acw-M5B9Js3sTD0qt5MIsWTaC3ZQS8n8G1Khy4A DFO. (1995). The streamkeepers handbook: A practical guide to stream and wetland care. Salmonid Enhancement Program, Department of Fisheries and Oceans. Eberhardt, A. L., Burdick, D. M., & Dionne, M. (2011). The Effects of Road Culverts on Nekton in New England Salt Marshes: Implications for Tidal Restoration. Restoration Ecology, 19(6), 776–785. https://doi.org/10.1111/j.1526-100X.2010.00721.x Johnson, M. F., Wilby, R. L., & Toone, J. A. (2014). Inferring air–water temperature relationships from river and catchment properties. Hydrological Processes, 28(6), 2912–2928. https://doi.org/10.1002/hyp.9842 40 Hecky, R. E., Campbell, P., & Hendzel, L. L. (1993). The stoichiometry of carbon, nitrogen, and phosphorus in particulate matter of lakes and oceans. Limnology and Oceanography, 38(4), 709–724. https://doi.org/10.4319/lo.1993.38.4.0709 Hutchinson, G. E. 1967. A Treatise on Limnology: Volume 2, Introduction to Lake Biology and the Limnoplankton. John Wiley and Sons, New York. Howell, E. T., Barton, D. R., Fietsch, C.-L., & Kaltenecker, G. (2014). Fine-scale nutrient enrichment and water quality on the rural shores of Southeast Lake Huron. Journal of Great Lakes Research, 40(1), 126–140. https://doi.org/10.1016/j.jglr.2013.12.009 King, D. L. 1970. The role of carbon in eutrophication. Journal of the Water Pollution Control Federation, 42: 2035-2051. Kirchman, D. L., & UPSO eCollections (University Press Scholarship Online). (2021). Dead zones: The loss of oxygen from rivers, lakes, seas, and the ocean. Oxford University Press. Lund, J. W. G. 1965. The ecology of the freshwater phytoplankton. Biological Reviews, 40: 231-293. MacKinnon, D. (2018). A restoration strategy for Lost Lagoon in Stanley Park, Vancouver, British Columbia. Simon Fraser University. Marchant, R., Norris, R. H., & Milligan, A. (2006). Evaluation and application of methods for biological assessment of streams: Summary of papers. Hydrobiologia, 572(1), 1–7. https://doi.org/10.1007/s10750-006-0382-y Mueller, G., & Nakamura, K. (2008). Review of the performance of the artificial floating island as a restoration tool for aquatic environments. World environmental and water resources congress 2008 (pp. 1-10). https://doi.org/10.1061/40976(316)276 Nordin, R. 2001 Update. Ambient Water Quality Criteria for Ammonia to Protect Marine Aquatic Life Overview Report. http://www.env.gov.bc.ca/wat/wq/BCguidelines/ammonia.html Null, S. E., Mouzon, N. R., & Elmore, L. R. (2017). Dissolved oxygen, stream temperature, and fish habitat response to environmental water purchases. Journal of Environmental Management, 197, 559-570. https://doi.org/10.1016/j.jenvman.2017.04.016 41 Shupe, S. M. (2017). High resolution stream water quality assessment in the Vancouver, British Columbia region: A citizen science study. The Science of the Total Environment, 603-604, 745-759. https://doi.org/10.1016/j.scitotenv.2017.02.195 UBC ESB Rooftop Weather Summary. (n.d.). Retrieved March 27, 2022, from https://weather.eos.ubc.ca/wxfcst/users/Guest/ubcrs_websiteLR.php?location=3510 Water quality and eutrophication. (2017). In Z. Ji (Ed.), Hydrodynamics and water quality (pp. 161-271). John Wiley & Sons, Inc. https://doi.org/10.1002/9781119371946.ch5 Wurts, W. A., & Durborow, R. M. (1992). Interactions of pH, carbon dioxide, alkalinity and hardness in fishponds. Southern Regional Aquaculture Center publication no. 464. Liming Fishponds 3. In Auburn University For. Worcester, R. (2010). State of the Park Report for the Ecological Integrity of Stanley Park (Stanley Park Ecology Society). https://stanleyparkecology.ca/wp-content/uploads/2021/07/SOPEI-Full-2010.pdf Yardi, K. D., Bharucha, E., & Girade, S. (2019). Post-restoration monitoring of water quality and avifaunal diversity of Pashan Lake, Pune, India using a citizen science approach. Freshwater Science, 38(2), 332–341. https://doi.org/10.1086/703440 Yanes, M., Velasco, J. M., & Suárez, F. (1995). Permeability of roads and railways to vertebrates: The importance of culverts. Biological Conservation, 71(3), 217–222. https://doi.org/10.1016/0006-3207(94)00028-O 42 Appendix 1: Water Quality Table 4. Comparison of inorganic phosphate (ppm), inorganic nitrogen oxides (ppm) except for ammonia, and pH between Beaver Lake, Lost Lagoon, forested watersheds in Vancouver (Shupe, 2017), and Lake Huron (Howell et al., 2014). Rows for Beaver Lake and Lost Lagoon show data collected for this project. PO4 (ppm) NO2 + NO3 (ppm) pH Shupe 0.03 0.31 7.3 Howell et al. 0.029 0.432 NA Beaver Lake 0.036 1.564 6.73 Lost Lagoon 0.024 0.424 9.05 Figure 27. Water temperature(°C) recorded in Beaver Lake (BL) and Lost Lagoon (LL). Blue marks represent LL, and orange marks represent BL. Data up to 2021 was collected by SPES. 2022 data was collected by ENVR 400 students. Note that from 2019 onwards, data was only collected during summer months, explaining the increasing trend. 43 Appendix 2: Stream Invertebrates Figure 28. The EPT index, EPT ratio, and predominant taxon ratio ratings for all stream invertebrate surveys from all creeks. Figure 29. The spring and fall The EPT index, EPT ratio, and predominant taxon ratio ratings for all stream invertebrate surveys from all creeks combined. 44 Appendix 3: Culverts Table 5. A table of the culverts surveyed for this project. The rough amount of substrate, measurements (width, height, slope), material, and extra comments was recorded. Each end of the culvert was given a rating of poor, fair, or good. The blue line indicates the division of culverts between Beaver Lake and Lost Lagoon. Above the line are the culverts surrounding Beaver Lake and below are the culverts surrounding Lost Lagoon. An overall rating was given to the culvert based on the lowest rating between the two ends of the culvert. Culvert # End (Upstream/ Downstream) Inside of the Culvert Width (cm) Height (cm) Slope (degrees) Material Comments Condition Overall Condition 151 D Half full Eff. 27 Eff. 11 0 plastic Filled with gravel Fair Fair 151 U Half full Eff. 31 Eff. 15.5 -3.4 plastic Filled with gravel Fair 152 D Clear 20 20 plastic Good Good 152 U Clear 20 20 plastic Good 153 D Full plastic Poor Poor 153 U Half full Eff. 10 Eff. 8 plastic Filled with mud End is broken Poor 154 D plastic Unable to measure because it is under rocks Visually looks good Good Good 154 U Clear 27 27 plastic Good 155 D Full 17 17 plastic Completely submerged under water Broken/crushed by rock Poor Poor 155 U Clear 17 17 plastic Completely submerged under water Poor 156 D Clear 13 13 plastic Good 45 156 U Full plastic Fully submerged in water Tall grass clogs the pipe creating a blockage Poor Poor 157 D Full plastic Poor Poor 157 U Clear 19 19 plastic Good 158 D Full Eff. 16 Eff. 7 Metal 75% filled with gravel Poor Poor 158 U Full Eff. 14.5 Eff. 4.5 3 Metal Good 159 Can't find 160 D Clear 14 14 plastic There is flow, but visibly buried in plant debris Poor Poor 160 U Can't find/Hidden 161 D Full plastic Can't measure Poor Poor 161 U Full plastic Can't measure Poor 163 D Clear 15 15 plastic Submerged in water, stagnant, doesn't appear to be blocked Fair Fair 163 U Half full 15 Eff. 8 plastic Good 162 a (white) D Clear 14 14 plastic Good 162 a (white) U Can't find/Hidden plastic Can't find Minimal to no water flow Clogged Poor Poor 46 162 b (green) D Clear 12 12 1 plastic Fair 162 b (green) U Clear plastic Hidden in reeds and mud Restricted by grass Fair Fair 164 a (lower) D Clear 15 15 plastic Submerged in water Good 164 a (lower) U Clear 15 15 plastic Clogged by leaf Poor Poor 164 b (higher) D Clear 15 15 plastic 5 cm above water level Good 164 b (higher) U Clear 15 15 plastic Clogged by leaf Water level not high enough Poor Poor 165 a D Clear 14.5 14.5 plastic Half submerged in water Good 165 a U Clear 14.5 14.5 4 plastic Half submerged in water Fair Fair 165 b D Clear 14.5 14.5 plastic Half submerged in water Fair Fair 165 b U Clear 14.5 14.5 plastic Half submerged in water Good 166 D Clear 14 14 plastic Submerged in water, no flow Poor Poor 166 U Full plastic Fully buried Poor 167 D Hidden plastic Hidden under wood board/soil Little to no flow Poor Poor 167 U Hidden plastic Can't find 47 170 a D Clear 15 15 plastic Water moves fast Fair Fair 170 a U Clear 15 15 4 plastic Fair 170 b D Clear 16 16 plastic Steep, minimal flow Fair Fair 170 b U Clear 16 16 plastic Channel is partially blocked with debris Fair 177 D Half full 25 Eff. 19 plastic Fair Fair 177 U Half full 3 plastic Fair 264 D Clear plastic Can't measure, hidden behind rocks Fair Fair 264 U Half full Eff. 13 Eff. 6 3 plastic Filled with gravel Fair 176 D Partially Full Eff. 13 Eff. 5 plastic Outflow blocked by gravel, log blocking water trail creating a water pool Poor Poor 176 U Half full 19 Eff. 13 plastic Filled with gravel Poor 131 a D Clear 38.5 38.5 1 plastic Algae on the bottom Comes from road Fair Fair 131 b D Clear 25 25 0 plastic Comes from road Can see oil coming through pipe Poor Poor 129 Can't find Hidden or submerged Comes from road 48 128 D Clear 20 Eff. 17 6 plastic Partially filled with gravel Fair Fair 128 U Clear 20 20 plastic No gravel Fair 127 D 15 15 plastic Outflow covered in tall grass Fair Fair 127 U plastic Hidden, unsure if coming from road or fully buried 66 D Clear 20 20 1 Metal Old, rusty, broken Poor Poor 66 U Metal Can't measure, grass clogging inflow, visually flow is okay Poor 65 D Clear 20 20 2 plastic plastic pipe joined together with metal pipe Fair 65 U Metal Old, rusty, broken Poor Poor 263 D Clear 40 Eff. 32 1 plastic Partially filled with gravel Good Good 263 U Clear 40 Eff. 30 plastic Partially filled with gravel Good 64 Not being used Been replaced Downstream end is visible, upstream buried/hidden 63 D Clear 15 Eff.14 0 plastic Small amount of dirt/gravel Fair Fair 63 U Clear 15 Eff. 11 plastic Partially filled with gravel Good 49 62 D Partially Full 15 Eff. 11 plastic Partially filled with gravel Good 62 U Half Full 15 Eff. 9 plastic Half full with gravel Fair Fair 71 D Clear 22 22 1 plastic Good 71 U Clear 22 22 plastic Inflow entrace blocked due to debris Poor Poor 72 D Clear 20 20 2 Concrete Drop off Erosion is present Poor Poor 72 U Clear 20 20 Concrete Poor 73 D Clear 20 20 3 Concrete Poor Poor 73 U Clear 20 20 Concrete Inflow entrance blocked due to debris (large branches) and mud This creates a pool and water cannot be properly drained Poor 74 D Clear 20 20 2 Good Good 74 U Clear 20 20 Good 75 D Clear 36 36 plastic Drop off, sharp right turn at the bottom causing erosion to the surrounding Poor Poor 75 U Clear 36 36 plastic Breaking but functionally good Poor 76 D Clear 20 20 3 plastic Good 50 76 U 20 20 plastic Inflow entrance has tree minimizing pathway, forms pool of water Fair Fair 70 D 16 16 1 plastic Exit has a hill of gravel blocking water from flowing down Fair Fair 70 U Partially full 16 16 plastic Good 69 D Clear 26 26 plastic Good 69 U plastic Big rock fallen on top of culvert slowing down/blocking water flow Poor Poor 68 D Clear 20 20 3 plastic Good 68 U Clear plastic Debris (sticks) in front of entrance blocking flow Poor Poor 67 D Clear 30 30 2 plastic Good Good 67 U Clear 30 30 2 plastic Good 126 a D Clear 15 15 4 plastic Fair Fair 126 a U Can't find plastic 126 D Full Eff. 9 Eff. 3.5 5 plastic Filled with gravel and dirt Poor Poor 126 U Half Full Eff. 11 Eff. 8 plastic Filled with gravel and dirt Fair 125 D Partially Full Eff. 11 Eff. 6 1 plastic Fair 125 U Can't find plastic Most likely buried Poor Poor 51 122 a D Clear 29.5 29.5 1 plastic Most of the water coming through this culvert Water coming from stream Upstream is caged Good Good 122 b (right) D Clear 15 15 1 plastic Coming from road Good Good 122 c (left) D Half Full Eff. 14 Eff. 7 0 plastic Coming from road Fair Fair 121 D Clear 15 15 0 plastic Algae visible at the bottom of the exit and inside the culvert Upstream buried on the other side of the trail Fair Fair 120 D Clear 15 15 0 plastic Fair Fair 119 Can't find Can't find Most likely buried by dirt/rocks 118 Can't find Can't find Could be under tall grass 117 D Clear 15 15 1 plastic Good Good 116 Can't find Can't find Could be under tall grass 115 a D Partially Full 30 Eff. 27 0 Concrete From stream on other side of the road Fair Fair 115 b D Half Full 15 15 plastic From road Good Good 113 D Clear 36 36 1 plastic Drop off Fair Fair 114 D Half Full plastic Under rock making it hard to reach to measure Fair Fair 52 114 U Clear 16 16 4 Fair 109 D Clear 30 30 3.5 Concrete Fair Fair 111/110 On other side of the road, caged 112 U Clear 3 culverts leading into one culvert connected to 109 Good Good 108 Removed No longer here, cleared for boardwalk 107 Removed No longer here, cleared for boardwalk 106 Removed No longer here, cleared for boardwalk 105 D Partially Full 85 Eff. 26 0 Metal Half a pipe to allow water flow under trail Fair Fair 105 U Partially Full Metal Pipe has no influence on flow Fair 104 Buried/ Removed Water pool where the upstream end should be 103 a D Can't find 103 a U Full 13 Poor Poor 103 b D Half Full 85 Eff. 25 Metal Half a pipe to allow water flow under trail Fair Fair 103 b U Half Full 85 Eff. 25 Metal Pipe has no influence on flow Fair 102 D Half Full 85 Eff. 28 Metal Half a pipe to allow water Fair Fair 53 flow under trail 102 U Half Full 85 Eff. 27 Metal Pipe has no influence on flow Fair 102 b D Half Full 85 Eff. 27 Metal Half a pipe to allow water flow under trail Fair Fair 102 b U Half Full 85 Eff. 28 Metal Pipe has no influence on flow Fair 77 D Full Completely buried No flow Poor Poor 77 U Full Culvert Buried Poor 77 b Recommendation Should make one here Currently water is flowing over trail 130 Couldn't measure 132 D Clear 15 15 4 plastic Significant drop Poor Poor 132 U plastic From road 258 D Full plastic Filled with ivy roots Broken Poor Poor 258 U plastic 135 D Clear 36 36 7 plastic Drop off Poor Poor 135 U plastic From road 259 D Partially Full 15 Eff. 10 4 plastic Exit covered in leaf debris Poor Poor 259 U plastic From road 54 260 D Clear 16 16 3 plastic Drop off Fair Fair 260 U plastic From road 136 D Partially Full 15 Eff. 10 4 plastic Fair Fair 136 U plastic 136 b D Clear plastic Top portion broken Couldn't measure Fair Fair 136 b U plastic 205 b D Clear Terracotta Top portion broken Could not measure due to high water level Fair Fair 205 D Metal Could not measure due to high water level Fair Fair 138 D Metal Looks steep Could not measure due to high water level Fair Fair 140 (white) D plastic Goes into Lagoon 140 (white) U 17 Eff. 14 9 plastic Can't measure Poor Poor 140 (green) D Clear plastic Slight drop off Fair 140 (green) U Clear 22 22 7 plastic Poor Poor 139 D Full 10 10 3 plastic Filled with mud and rocks Poor Poor 139 U Full plastic Buried/clogged Poor 55 Water flowing over trail 141 D plastic Culvert is broken, but functionally okay Fair Fair 141 U Can't find 142 D Clear 10 10 3 plastic Drop off Exposed Poor Poor 142 U Clear plastic Covered in twigs/debris Fair 143 D Full 14 Eff. 10 1 plastic Filled with mud, not working properly Poor Poor 143 U Can't find 262 D Clear 20 20 4 plastic Drop off Fair Fair 262 U Clear 20 20 plastic Fair 124 D Clear 25 25 3 plastic Good Good 124 U Clear 25 25 plastic Good 300 D Clear 14.5 14.5 1 plastic Good Good 300 U Clear 14.5 14.5 plastic Good 301 D Clear 10 10 3 plastic Good Good 301 U Clear 10 10 plastic Good 123 D Clear 4 plastic Both sides clear, but no water flow. Most likely means inside is clogged Upstream end has flooded Poor Poor 123 U Clear plastic Poor 56 101 D Clear 31 31 3 Concrete Two streams flowing in Unsure if connected to Lost Lagoon Good Good 101 U Clear 31 31 2 Concrete Good 100 D Clear 31 31 3 plastic Good Good 100 U Clear 31 31 plastic Good 81 (green) D Clear 21 21 1 plastic Drop off, higher than white Good Good 81 (green) U Clear 21 21 plastic Good 81 (white) D Clear 14 14 plastic Good Good 81 (white) U Clear 14 14 0 plastic Good 244 D Clear 30 30 1 plastic Fair Fair 244 U Clear 30 30 plastic Fair 80 D Clear plastic 80 U Clear 4 plastic Top is broken Poor Poor 245 D Clear 30 30 1 plastic Good Good 245 U Clear 30 30 plastic Good 79 Can't find 78 (two) D Clear 18 18 0 Metal Deposition of sand Poor Poor 78 (two) U Clear 18 18 Metal Poor 57 Appendix 4: Project Process Figure 30. Precedence diagram for the whole project. Figure 31. Precedence diagram for the proposal. Figure 32. Precedence diagram for the data collection and analysis. Figure 33. Precedence diagram for continued literature research and final report. 58 Figure 34. A Gantt chart showing the planned timeline of this project.
Report
eng
Unreviewed
Vancouver : University of British Columbia Library
Attribution-NonCommercial-NoDerivatives 4.0 International
Undergraduate
University of British Columbia. ENVR 400
Recommendations to improve the large freshwater body ecosystems of Stanley Park based on water chemistry, stream invertebrates, and culvert data
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