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Stormwater ManagementShana – Mayor, Members of the City Council, Planning & Zoning Commission members –Thank you for being here this evening to discuss the very important issue of stormwater management. This presentation has been developed for you by the Quality Development Focus Area Cabinet. I’ll explain more about the role and responsibility of this cabinet in a moment. I like to think of this group as our “bricks and mortar” team, which includes PW Director Bob Price, PDS Director Ken Baker, ED Director Greg Last, CS Director Chris Tribble and Community Relations Officer Pilar Schank. The members of the cabinet are here this evening to make the presentation and answer any questions you may have. Also present is Joe Walsh. Joe is the face of Streets and Drainage in the City of Southlake. Joe is available at any point this evening to answer any questions to what he sees in the field. Stormwater management and erosion control is a significant issue as identified in the last several citizen surveys, and is a very complex issue. During tonight’s presentation, we will be discussing policy, obligations, responsibilities and the legal framework as it pertains to the City of Southlake. We will be discussing the responsibility of both the City and private property owners. While the City of Southlake certainly has responsibility for certain aspects of stormwater management, we are not the answer to all of the questions. 1 Shana- This is the City of Southlake Strategy Map, adopted by the City Council and the guiding principle for resource management. As you will notice, “Quality Development” is one of the Council’s highest priorities. It is one of six focus areas. A staff team has been assigned to each of the focus areas to ensure that we develop initiatives to support these priorities. These groups, called Focus Area Cabinets, develop annual plans to make sure that we support this priority. Tonight’s discussion about drainage and storm water management is aligned with the city of Southlake strategy map in the area of quality development. From the perspective of Managing the Business, we will be addressing Council’s corporate objectives through implementing and sharing best practices across all departments. Also, our efforts in storm water management meet the city’s corporate objectives in the area of collaborating with select partners to implement service solutions. Investments made in storm drainage improvements fall in the corporate strategic objective of investing to provide and maintain high quality public assets. 2 Shana – We appreciate you taking time to meet with the staff tonight to discuss storm water and drainage in the City of Southlake. Staff often receives requests from citizens to address drainage issues which are, in reality, their responsibility. However, there are many drainage issues that do indeed fall into the realm of responsibility of the local government. First, we would like to discuss a few key terms in the area of drainage as a subject as well as drainage within the city of Southlake. Once we cover a basic terminology and confirm that we all are on an equal knowledge plane, we would like to discuss the need for drainage policy. As part of tonight’s discussion, we will be discussing the current drainage policy in the City of Southlake. We will be discussing federal programs that have been created to reduce flooding, and the requirements for those programs for which the City of Southlake participates in such as the National Flood Insurance Program, otherwise known as the NFIP. We will be discussing existing city regulations and procedures for dealing with drainage development and drainage related issues Later in the evening, we will be discussing the role of staff in drainage related matters. And, we will be visiting the roles of elected and appointed officials as well as the responsibility of private property owners in drainage related matters. We will discuss the processes employed by the city in the development of the city and discuss how drainage policy impacts those processes. Finally, toward the end of the evening, we will wrap up with the City Attorney discussing the Legal Framework of Federal, State and local laws and regulations. 3 4 So why is it that the City of Southlake needs drainage policy and regulations. Proper storm water and drainage policy can fulfill a number of needs for the citizens. The orderly development of any municipality is based upon good planning. When dealing with storm water, we, as municipal officials must be plan for certain periods of time when rainfall will be prevalent and must be dealt with. If proper drainage systems are not constructed for the anticipated runoff, then potential financial loss to property owners may result. Drainage policy also delineates the responsibilities of all of the stakeholders in the municipal drainage system: the elected and appointed officials, city staff and private property owners. It is important that the city communicate the responsibilities of these various stakeholders to each group. Failure to control the anticipated rainfall events can end up causing unnecessary property loss and costing everyone in the city and the region. That is the very reason that the North Central Texas Council of Governments has undertaken development of regional storm water management practices. NCTCOG refers to this program as ISWM or the Integrated Storm Water Management System. Southlake utilizes the ISWM manual and practices as does the City of Fort Worth and many other North Texas cities. Natural Resources such as water are key to our survival on this planet. Water is a scarce resource and we must take care of and protect our creeks and streams from pollution as these feed into our water drinking supplies. Sediment from construction sites, runoff from developed properties including fertilizers can choke off oxygen in our creeks and streams and upset the delicate ecosystems for our area’s wildlife. In 1972, the United States Congress passed legislation to protect our nation’s creeks and streams. This legislation is referred to as the Clean Water Act. It established many of the regulations that we are required to enforce today. Also, the Federal Government has established programs such as the National Flood Insurance Program to encourage municipalities, counties and states to restrict development within corridors established for the purpose of allowing water to runoff during rainfall events otherwise known as floodplains. Mortgage companies require property owners to purchase flood insurance on properties that are affected by these floodplains. Mortgage companies do this to mange their risk. Each of these above mentioned reasons suggest that there is value to underscore the importance municipal drainage policy and regulations. 5 Shana – This is a map of the city showing that the city of Southlake is drained by two major basins. Generally speaking, the area shown north of the red line drains toward Lake Grapevine. Please note that the blue arrows indicate the direction of flow. Likewise, the area to the south of the red line drains toward bear Creek, and ultimately to the Trinity River in the eastern portion of the Metroplex. At this point, I would like to turn the presentation over to Bob Price who will provide you with more specific information about these topics. 6 Bob - It has often been said that drainage is art more so than a science. In actuality, it is both, part art and part science. The portion of drainage to determine the quantity of water in a particular drainage basin is referred to as hydrology. The development of the quantity of water from a particular storm or rain event is based upon historical rainfall data collected over a number of years. All rainfall events vary in both intensity and duration. Because storm events vary in these two different ways, it is necessary for the science to be based upon statistical chances of occurrence. Hydraulics is the study of fluids. Hydraulics helps us to determine the actual flow characteristics of drainage. Any time, objects block the flow of water in the flood plain or any other path, the characteristics of the flow will change. This is where knowledge and experience of the design engineer comes into play. Many things such as density of housing, soil type, impervious area affect the amount of storm water runoff. By requiring a maximum impervious area for development, we can reduce the amount of runoff by allowing water to seep into the ground, under normal conditions. It should be noted, however, that in heavy rainfall periods, the amount of impervious area will impact the actual amount of runoff, very little. When the ground becomes saturated, all additional rainfall runs off while very little seeps into the ground. In Texas, storm water runoff is not currently required to be treated. Storm water runoff is not combined with sanitary sewer flows, as in other parts of the nation. As noted earlier, all storm water runoff, ends up either in Lake Grapevine or bear Creek. During periods of dry weather, we here in Southlake deal with runoff from excessive irrigation and groundwater. The source of the groundwater in our city is primarily a result of water traveling crevices in the ground. The fact that we have very sandy soil in the area also allows water to travel though the ground at subsurface levels. 7 Bob- We have provided you a list of definitions that you may wish to refer to during the evening’s discussion. If during our conversation this evening, I begin speaking in engineering-ease or use a term you are not familiar with, please do not hesitate to stop me. These terms and definitions are used in the National Flood Insurance Program, the ordinances of the City of Southlake and the regulations of the state and federal government. We can run through and highlight a few of these. If there are others that you wish to ask me to clarify, please do not hesitate to ask. Page 1 – Page 2 – Page 3 – Page 4 – Page 5 – We have also provided you with a set of frequently asked questions regarding the National Flood Insurance 8 Program and why it is important to the City of Southlake to enforce floodplain regulations. Bob – Here are just a couple more terms that often are misunderstood. They are key to any discussion related to drainage. These terms are the standards by which we require improvements to be designed. It should be noted that the values associated with each of these storm events are based upon historical rainfall records. A 100 year storm has a one in 100 or a 1% chance of occurrence in any given year. Likewise, a 10 year storm has a one and 10 or 10% percent chance of occurrence in any given year. And finally, a two-year storm has a one-half or 50% percent chance of occurrence in any given year. To give you some perspective, for a storm of a duration of 15 minutes, a two-year storm is approximately 3.9 inches of rainfall in an hour, a ten-year storm produces approximately 5 and ½ inches per hour and a one-hundred year storm produces 7.98 inches per hour. The intensity and duration determine the amount of water that we will need to deal with in a particular storm event. The next topic we would like to discuss is the differentiation between public and private water. Water is water, so how is it that some is private and some is public. Determining if water is public or private is determined by the property rights of the ground upon which the water is flowing. The basic premise of Texas Water Code is that water must be allowed to flow where it naturally flows. One cannot obstruct the flow of water. If water is flowing in a street, a borrow ditch, or a defined drainage easement, then the water is considered to be public. If the water is flowing on private property that is not platted or dedicated with a public drainage easement, the water is considered private. The City’s developer agreement spells out that Retention ponds are private amenities that are the responsibility of the private property owners, in many cases this is the Homeowners Association. Furthermore, specific responsibilities of maintenance are spelled out in the city’s drainage ordinance 605, adopted in 1994. We will discuss these various maintenance responsibilities more in depth a little later. The maintenance responsibilities outlined in the ordinance are consistent with those in other local municipalities. 9 Bob— Here is a visual representation of the differentiation of public and private water ways. As you can see, public and private water can exist right on top of each other. This is where things can get “muddy” on private versus City responsibility. Again we will discuss the specific maintenance responsibilities of the city and the private property owner a little later. Please note in the top view that the retention component of a pond is the responsibility of the HOA or private property owners adjacent to the pond. It is the detention component of the pond that the city is most concerned with from a drainage perspective. Is this portion of the retention pond that reduces impact on downstream properties. In the bottom view, you’ll notice that the public drainage easement flows through the private amenity referred to as the retention pond in the sketch. Again, the retention pond is a private amenity and the city does not hold any maintenance responsibility for it. 10 Bob— Detention basins are utilized in the city of Southlake in order to reduce the peak flow downstream. Detention ponds are designed for upstream fully developed conditions which occur during a 100 year storm event. Retention ponds permanently restrain the flow of water. Generally, retention ponds are for aesthetic purposes only. Remember, that the retention component of a pond is the responsibility of the HOA and/or landowner. Practice prior to the last 2 years has been to provide a discharge for the 100 year storm only. Starting approximately two years ago, Engineering staff has begun requiring staged discharges for the two, the ten and 100 year storm events. Prior to the implementation of this requirement, the ponds did not provide any detention for any storm event other than the 100 year storm. What that means is that detention ponds constructed prior to two years ago, do not detain water except in the largest of storms. 11 This picture the detention pond, may help to clarify some of the points that were made in previous slide. Please note the outfall structure. When a heavy rainfall event occurs, the water may build up in the pond and gradually flow out of the pond over an extended period of time. The lower box is pointing to the retention component, which is the responsibility of the age way for property owners Association for the development agreement. The top box refers to the detention component that the city is most concerned with from the drainage system perspective. 12 Bob– Two basic premises of the Texas for all to consider are that you cannot divert or block the natural flow of water. Is also important to realize that any individual and group of individuals cannot adversely impact any other property by restricting or changing the flow of water. 13 Bob – This slide demonstrates the floodplain, and that is utilized in the national flood insurance program and famous flood insurance rate maps. It is often thought that development may not occur within the floodplain. That is actually not correct. Please note that the floodplain consist of a floodway in a flood friendship on either side of the floodway. Together these three components comprise what is referred to as the 100 year floodplain. The area shown as the flood prevention can be reclaimed or filled according to FEMA’s rules. The area which is reclaimed is dependent upon the anticipated rise in water surface elevation upon filling. I have also indicated a picture of one of the Flood insurance rate maps for the City of Southlake on the left side of this slide. 14 15 Bob— The National Flood Insurance Program is administered by the Federal Emergency Management Agency, otherwise known as FEMA. Southlake has been a participant of the NFIP since 1974. As a participant in the National Flood Insurance Program, the City of Southlake is obligated to enforce floodplain development in accordance with rules and regulations of FEMA. For various improvements within the floodplain involving wetlands, the United States Army Corps of Engineers may also be involved. As mentioned above, the responsibility for the environmental protection of our creeks and streams was originally assigned to the Environmental l Protection Agency and subsequently delegated to the Texas Commission on Environmental Quality. Finally, the responsibility was passed onto the city of Southlake several years ago. The city is tasked with enforcement and protection of the water quality within the city’s creeks and streams through Phase 2 of the Clean Water Act. 16 Bob – The city of Southlake first established drainage standards in 1974 with the passage of Ordnance 217. Subsequently, the City of Southlake repealed 217 and adopted ordinance for 482 in 1980. Subsequent to that adoption, the city of Southlake again improved its drainage standard by adopting Ordinance 605. In 1995, the City of Southlake employed Cheatham and Associates to prepare a critical drainage structure study. With the development of the study, developments are required to pay a proportionate share of downstream drainage improvement costs. In 2006, the City Council adopted a storm water utility via the adoption of ordinance 900 and 901. The storm water utility provides funding for maintenance of the city’s drainage infrastructure and local and regional drainage improvement projects. As you may recall, based upon 2007 dollars, only 13% of the city’s drainage needs will be met over a 10-year time horizon of the storm drainage utility at the current rate of collection. In 2007, Phase II of the Clean Water Act was implemented by the Texas Commission on Environmental Quality. It is at that time that the City of Southlake became responsible for the protection of creeks and streams contained within the City of Southlake. In February of 2008, the City of Southlake was required to submit a storm water management plan for the next five years. CLICK and discuss SWMP. In October of 2008, the Southlake City Council adopted a new erosion control ordinance for construction activities. Many of the terms of this ordinance were already covered in the Texas construction general previously administered by the TCEQ. During 2009, staff will present new ordinances for council consideration, one dealing with illicit discharges, and one dealing with best management practices in dealing with drainage and floodplains. Both of these items are referred to as minimum control measures which must be addressed by the City of Southlake. 17 Bob— The slide outlines the development process, and begins to identify the roles of the staff and the elected and appointed officials. As you well know, during the preliminary review of the development as well as the development review committee process, the staff is tasked with reviewing the development to ensure that the master plans and development related standards are met. The developer and his development team is made aware of any noncompliance issues that the staff discovers. However, specific design issues are very difficult to identify as the plans presented at this stage are very preliminary. One may ask why the city would not require more in depth analysis by the developer’s engineer during the preliminary phase. The primary reason is one of economics. Due to the rigorous entitlement process here in Southlake, the risk of spending the cost dollars to engineer the development before the developer knows whether he has a viable project would be considered risky by some. As a result, the potential cost of development may be considered as being too great and may adversely impact land development within the city. During the site plan and zoning phase for particular developments, the Planning and Zoning commission and City Council become involved in the review and authorization of a particular development. Once the zoning and site plan are approved by the Planning and Zoning Commission and the City Council, the developer may choose to move forward with the development of construction documents. Upon a satisfactory review of the construction documents for public improvements, including drainage and possibly detention and/or retention, the construction plans are released for construction by city staff. The construction of the public improvements is inspected for compliance with the construction plans which are “released for construction” as well as city standards. 18 19 The role of staff is varied: It is the role of staff to draft proposed city policy relative to the development of the city as it is relates to drainage and other development issues. The staff acts as the floodplain administrator. The floodplain administrator is tasked with enforcing the development policy and regulations of the city. Participation in the National Flood Insurance program requires that we enforce minimum requirements relative to floodplain development. Staff is responsible for reviewing all developments for compliance with the city’s master plans, Federal and state Laws, local ordinances and regulations. Staff informs Council in staff development reports as to the ability of the proposed developments to address the above mentioned plans and laws. The City staff is also responsible for the administration of the City’s Storm Water Management Plan as submitted to the Texas Commission on Environmental Quality. Remember there are six minimum control measures that we are accountable to accomplish over a 5 year period. The city staff is responsible to develop and administer a Master Drainage Plan. The city of Southlake has developed a Preliminary Master Drainage Plan. This adoption of the Master Drainage Plan will take place during the Southlake 2030 20 Master Plan Development process. Focusing more specifically on the role of tea appointed and elected officials. The planning and zoning commission and city Council are responsible for considering the adoption and establishment of city ordinances, including drainage policy in the adoption of the master drainage plan. The development of a master drainage plan is underway, and will be part of the 2030 master plan update. During the entitlement phase and site plan approval process, it is the role of the appointed and elected officials to confirm that staff has determined that the city’s master plans, ordinances and regulations are being met by the development or variances are being approved. In addition, the City Council adopts a budget for the capital improvement program, including drainage related projects. The council also adopts a storm water utility operating budget each fiscal year. 21 Earlier in tonight’s discussion, I referred to Ordinance, 605, the city’s drainage ordinance and the maintenance responsibilities of the city as well as private property owners. In Section 9.02, The ordinance specifies the responsibilities of the city and private property owners. With respect to natural drainageways and drainage easements with no structures included. It is the responsibility of the private property owner to routinely maintain all creeks and streams and natural drainageways in all unimproved drainage easements on his or her property. This main show include periodic removal of fallen trees, limbs and underbrush, periodic ruffed mowing. Removal of trash and debris and general upkeep to maintain a positive flow of storm water within the drainageway or easement. With respect to drainage easements with surface structures it is be the responsibility of the city to maintain all surface structures within a drainage easement. The landowner shall maintain all portions of the drainage easement which are not improved. Finally, with respect to borrow ditches and culverts, maintenance of these items shall be the responsibility of the individual landowner despite these items being typically located within the right-of-way, which is dedicated to the city. The maintenance responsibility of the landowner shall include periodic removal of underbrush, periodic rough mowing, removal of trash and debris and general upkeep of the borrow ditch or culvert to maintain a positive flow of storm water within the borrow ditch or culvert. Maintenance shall also include periodic cleaning of culverts to remove all sediment or other hindrances to the flow of water. Culverts shall be replaced by the owner should any structural failure in the culvert potentially impede the flow of water. Paragraph D of this section of the ordinance states that failure on a landowner’s part to maintain drainage easements, drainageways and/or culverts in accordance with this section may have a lien placed on their property for work performed by the city to accomplish this task. 22 23 At this time, I will be have to open it up for discussion and or questions. Once we have completed the discussion, we will ask that the Council recess and reconvene in Executive Session for the purpose of discussing the legal framework of tonight’s discussion with the City Attorney. 24 25 26 27 28 29 •Stormwater utility allows you to solve existing problems as well as future problems; for example, impact fees can only be used to solve future problems. •Stormwater utility allows you to issue revenue bonds exclusive to the utility just like water and sewer bonds. 30 •From these sources, we identified: •402 localized projects •17 secondary projects •And 20 primary projects throughout the City •and which add up to $51.9M. 31 •$7M in capital drainage projects represents only 13% of the current problems that have been identified. 32 The EPA was specific in what general areas municipalities were to focus on during the development of a program to improve water quality. The general topics to address are: Public Works has developed the plan of action to -identifying goals -and measurements of those goals in annual increments. These goals are: -interdepartmental -and range from simple activities to complex organization. Each goal was chosen according to the -regulation guidelines, -the goal’s feasibility for Southlake, and -its apparent effectiveness. 33