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HomeMy WebLinkAbout2007.00.00 - Loggy Documentation of Differences of Wetland Ratings and AnalysisLooT L,o1q''l DOCUMENTATION OF DIFFERENCES OF WETLAND RATINGS AND ANALYSIS OF DRAINAGE DITCH CRITICAL AREA Part I Comparison Of Wetland Investigations The following covers the differences in characteristics of the wetland located on Carol Wise and your property (Parcels 001033006 and 0010033007) from our original field inventory study and to the decision by Rick Mraz, aWetland /Shorelands Specialist, who conducted a third party review and re- classified the wetland to a Class III from a Class IV and recommended the size of the wetland be expanded. As we discussed in your office the amount of wetland expansion will not greatly affect your project from the plan that your engineer has presented with the 80 foot buffer, As we discussed the increase is not worth the time and expense to fight the change with the City of Port Townsend.and Department of Ecology. We have made the adjustments to the wetland and buffer boundaries. You will have to have a qualified and licensed surveyor survey the location ofthe wetland and buffer boundaries. I do think that it is important to document apparent wetland hydrolory changes in the wetland from the Loggy Soil and Wetland Consulting inventory in August 2006 and the third party review (conducted on June 20, 2001) andreporting of the wetland hydrology. My main concern is the flooding and the interpretation that was made by the amount of algal mats reported by the third party and what Loggy Soil and Wetland consulting (David Loggy and Kimberly Meeham-Roulst) observed in the original inventory. At your request and I revisited the wetland on July 7,2007 What we found as far as ( -algal mats was what was detritus deposits of sediment and other debris along with the algal mats. The amount and area of detritus deposited in ttre wetland between the time of the initial review and the third party review is a very conspicuous wetland hydrology indicatorthat would be recognized by any wetland specialist regardless oflength ofexperience. This amount and extent of the very conspicuous algal mats and other deposited detritus were not present during the initial inventory. During ttre initial inventory detritus deposits included a very thin algal deposit were found in a very small area in the main drainage ditch at the lowest point in the wetland. The algal mats and other detritus material found during the initial inventory was insignificant compared to what was deposited sometime after the initial inventory. If flooding and impounding of water within the wetland was on a seasonal basis that appears to have happened after the inventory, this same amount or similar amounts of detritus would have been evident during the inventory. The amount and area of algal mats and other detritus materials present suggest a significant flood and impounding event above flooding and impounding events occurring in previous years, If this was the normal flooding and impounding conditions occurring yearly on the wetland, algal mats and other detritus deposited materials would be present in these amounts on a yearly basis. This amount of detritus deposit is going to be present for ieveral months, even into next year before they are removed by precipitation or by a subsequent flooding and impounding event. Based on the hydrology indicators we observed at the time of our inventory, our conclusion was that the wetland did not have significant flooding problems, at least not for several years and the area flooding and impounding was less than tA of the total wetland areafor at least 5 out of 10 years. We rated D. L4 as such, according to the indicators that we observed. As for rating D3.2 in the Hydrologic Functions section we did not observed any hydrology impounding indicators that merited impounding at or greater than 0.5 feet. If we had observed hydrology indicators indicating such cbnditions we would have rated as such. I still believe that the wetland should be a Class IV Wetland because the hydrology indicators found during the third party and are still present at this time, is a one time event and does not represent flooding and impounding of the wetland. It is evident that there was a large change in the hydrology in the wetland through increase water discharge to the wetland. There are two conditions which probably contributed to an increase height and duration of flooding and water impounding. In actuality it is probably a combination of causing the flooding, higher impounding and significant detritus deposit to occur. As we discussed you may have some recourse for the possible increased hydrology discharge onto and affecting your wetland. J s-^il I The first is an above average precipitation in November and December of 2006. Port Townsend records indicate precipitation in 2006 for November was 3.62 inches followed by 2.53 inches in December for a total precipitation of 6.51 for the two months. This is well above November's 52year meanof 2,49 inches and nearly the December 54 year mean of 2.57 inches. Total precipitation for the two month in 2006 was 1.45 inches more than the 58 year mean of 5.06 inch. From January thru June 2007 ihe precipitation for each month has been approximately one half of each month 58 year mean, Port Townsend can expect to exceed 4 inches of precipitation in November and 3.9 in December in one year in 10 (Jefferson County Soil Survey, 1975). Due to the difference in elevation (150 feet) and topographic conditions between the Port Townsend recording station and the wetland, the general area of the wetland could have exceeded 4 inches in November. One other major condition that can significantly increase or decrease the function of a wetland is to change the wetland's hydrology through changes in land management practices. When we did our study we looked for other wetlands in the vicinity that could affect the function and value of the wetland on your property. We paid special attention to the Molotsky property to the west of your property because aerial photographs indicated a ditch connecting to the ditch on your property. Our rbview of Molotsky property showed the ditch had not been maintained for years and represented more of swale than an incised drainage that is present on your property. The field was so over grazed that the only evidence ofany wetland areas present on the proper{y were one or two areas supporting individual and clumps of soft rush (Juncus effusus). Driving west on Hastings on May 7,2007, Kimberly and I observed a new excavated ditch on the Molotsky Property. On that date the ditch appeared to start from the most southern wetland on the property and went east to your property. The earth berm was quite obvious since vegetation growth was not very high. We do not know when the ditch was excavated but since you observed a backhoe excavating in the vicinity of the old ditch site on (date to be added), HAVE TO GET DATE FROM ANNE TO COMPLETE. Having the runoff from a high fall and winter precipitation period in (November and December) of 2006 plus with a new excayated ditch directly runoffto the ditch on your property is definitely a conduit directing increase surface and subsurface storm waters flow onto your property, Not only onto your property but ttrroughout the entire reach of a Port Townsend critical drainage conidor that terminates at Kai Tai Lagoon (Refer to Part II of this report for discussion on'ocritical drainage conidor"). In addition there would be quicker response to surface runoff increased flow from the wetland on the Molotsky property if the ditch entered one or more ofthe wetlands on the property. The new ditch would be the source bf additional sediment and other detrifus material discharged to your wetland during periods of intense precipitation resulting in rapid response runoff. At this time we have not found any culverts that would discharge runoff from the wetland north of Hastings Street onto yours' or Molotsky's properties. Kim thought that she had found a culvert just at the east side of the intersection of Thomas and Hastings Streets but it tum out that what she found was not a culvert. As we both know the presence of the ditch was masked by the height of the grass vegetation by the time of the third party review was conducted and the visit by Loggy Soil and Wetland Consulting on July 7,2007. Itwill be hard to really assess the physical characteristics of the ditch without gaining access to Molotsky property, which I can pretty much guarantee that access would be denied to both us. The ditch on Molotsky's property is in violation of Federal and State regulations of draining wetland if the ditch enters or occurs on the edge of the southern most wetland on the property. Although, the planning department related to you that they do not have regulations governing the re-excavation of the ditch. f fully disagree. First, a permit apparently was not secured to re-excavate a ditch that has not been maintained for several years (more than 5 years). I have discussed the conversion of drainage ditches to regulated wetland in Part II of the report. Under PTMC 19.05.040 "a critical area permit is required for a development proposal whenever a portion of the site is within the a critical area or required buffer area or whenever the director makes a finding that a development proposal is likely to significantly impact a 2 critical area (regardless of its location). The re-excavation of the ditch does and will affect wetland critical areas. Not only, ones on the Molotsky property but also the wetland on your property as represented by the significant increase in detritus deposits on your wetland compared to previous years. [E.,ruQ Now, if they cannot use Section 19.05.040 to enforce some charge of violation then DSD can suily bring regulatory pressure to bear through PTMC Section 19.05.090. The re-excavation of the ditch if it followed the old ditch line or within 25 feet on either side it occur in a documented and desigrated critical drainage corridor having a25 foot buffer on each side of the ditch which is govemed under PTMC 19.05.090 Critical area3 - Frequently flooded areas and critical drainage corridors. Under Section 19.05.090 D2 it states that "development shall not reduce the effective base flood storage volume. Effective storage capacily must be maintained. Filling of critical drainage corridors is prohibited." D2 does not speak specifically to drainage but if you'install or re-excavate a drain ditch, in this case in a critical drainage corridor you have to be reducing the effective base flood storage volume. What other reason would a person re-excavate a drainage ditch but to enhance drainage on the properly and discharge ofwater off the property. D5 of that section states that "no mechanized power equipment may enter or be used within i critical drainage corridor without the explicit approval of the DSD director. Your sighting of the backhoe on the property in or within the vicinity of the old ditch line indicates the use of equipment in the critical drainage corridor. An, finally, D8 under that section requires native and existing vegetation shall be maintained to the extent possible. If you effectively drain an areayou most likely will not be able to maintain native vegetation, especially dominant wetland species, an$ may change the overall existing vegetation community. J ) Part II Drainage Ditches and Applicable PTMC 19.05 Critical Areas The following information and discussion covers the drainage ditch on Molotsky and your properties. The old drainage ditch in question starts at the southeast corner of Thomas and Hastings Streets, crosses Molotsky'i property (Parcel 001033003) in a general southeast direction and enters on the southern portion ofparceiOOjO:IOOZwhereitthengoeseasttoandacrossParcel00l033009. Theditchexistsnearthe southeast corner of Parcel 001033009. The ditch is directly associated with 4 wetlands between the 3 parcels. Three of the wetlands are on the Molotsky propefty and one on Carol's and your properties. There are two places in the PTMC Chapter 19.05 that can address the ditch as a water conveyance and one section as a wetland. The first is under Section 19.05.080 Critical area2 - Fish and witdlife habitat conservation areas (PTMC Chapter 19.05). The ditch could be generally addressed as a stream or water conveyance under Section 10.05.080 B 6. This section identifies fish and wildlife habitat conseryation areas as "streams or waters of the state (see WAC 190-080 (sXaXvi)) that provide habitat to endangered or threatened species, or certain species that have been identified as being sensitive to habitat manipulation, as defined m WAC 222-16-030,Forest Practices Rules and Regulations". WAC 190-080 (5) (a) (vi) strictly refers to kelp and eelgrass beds and hening and smelt spawning areas and has no bearing on the present water conveyance structure. WAC 222-16-030 addresses the water typing system (Type l, 2,3, 4 and 5 Waters) appiieO by the Washington Department of Natural Resources (DNR) under forest practices application The state considers all water conveyance systems to be "natural waters" except it excludes water conveyance systems which are artificially constructed and actively maintained for irrigation (Section 222-16-031(6) (d). The entire drainage ditch crossing all three of the parcels meets Washington State Department of Natural Resources (WSDNR) meets the definition of "natural waters Q22'16-031(6) (d)"' As such the ditch does meet the requirements defining a Type 5 Water (WAC 222'16-031(5). I do not think that the city will want the ditch to be just classified as a Type 5 Water and be buffered as a Type 5 Water because ofihe other two sections covering water conveyances and wetlands may provide better and more logical way to manage the drainage way and provide more overall protection to city identified critical areas and facilities. . The second place that can cover the ditch is under Section 19.05.110 Critical area 5 - Wetlands. Usually, regulated wetlands do not include those artificial wetlands intentionally created from non wetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, waste water treatment facilities, farm ponds and landscape amenities and those created from road building after July l, 1990. These wetlands are considered facilities and require maintenance' Since most of the ditch was built within upland it would be considered non wetland facilities even if the ditch itself eventually developed wetland characteristics. Once these facilities are not maintained for a period of more than fivei5) yeari, yet still retain wetland characteristics, they revert to regulated wetland status ifthey meet the paiameteri of the regulated wetland definition. In the letter from Suzanne Wassmer sent you, it stated that according to Judy Surber, "it is likely that the sewer line would be considered "moderate" but it isn't specified in the Code, so we first need to review your proposal for the sewer line." Judy Surber may be approaching the management of the ditch as reverting to a regulated wetland because it has not been maintained foittre past 5 years. Because the ditch was established in upland the ditch probably will not classi$ as a wetland but the vegetation criteria for wetland would be very questionable. Soils along the side oithe ditch would be the defrning characteristic determining whether the ditch would be classified as a wetland now. If this would occur the ditch impact could classified as a moderate land use type assuming the word "moderate" in the email letter means land use type under the wetland rating system. Then the question is what Class of a wetland would the ditch rate out to be. For example if the ditch classifies as a Class IV Wetland, the buffer would be 40 feet on both sides of the ditch A wider width than a precedence setting 25 foot buffer for a critical drainage corridor discussed below. 4 The third place that covers stream or watercourses is under Section f 9.05.090 Critical area 3 - Frequently flooded areas and critical drainage corridors and the definition ofcritical drainage corridors (Section 19.05.020 Definitions). The term "critical drainage corridor" is "an area which has been determined (by the Port Townsend department of public works) to require more restrictive regulations than city-wide standards afford, in order to mitigate flooding, drainage, erosion or sedimentation problems which have resulted or will result from the cumulative impacts of development and urbanization". ' Critical drainage corridor is "defined as a year-round or intermittent naturally flowing watercourse which exhibits but is not limited to one or more of the following characteristics: l A stream or watercourse formed by nature or modified by humans; 2. Generally consisting of a defined channel with a bed for a substantial portion of its length on the lot;3. Watercourses which exhibit the above characteristics and have been channelized or piped and/or 4. Perched ponds, ravines or other natural drainage features. When considering the above broad requirements for a "critical drainage corridor" the ditch located on the Mclaughlin and Wise property (Parcels 001033007 and 001033006) does meet characteristic no. 3 to be considered a critical drainage conidor. Besides meeting the above characteristic (l-3) for qualifuing to be a critical drainage corridor, past inventory decisions and locations ofpresent channelized or piped watercourses support the ditch as being classified as a critical drainage corridor. I recommend that the ditch be classified as a critical drainage corridor for the following reasons. l. The ditch across Molotsky's property (Parcel 0010330033) before entering Parcels 001033007 and 001033006 was identified as a critical drainage corridor during a wetland inventory conducted on Molotsky's property (Coot Company, 1998). 2. When the ditch exits Carol's and your property (Parcels 001033007 and 001033006) it continues as an open drainage ditch to a wetland at the southwest corner of Hancock St. and 25* St. At this site the watercourie is piped along 25th Street to Sheridan St. From this intersection the drainage , corridor i, un op"n ditchio tqft Si From 196 St it is piped along Sheridan St to 16th St. From l6th St it is piped to a natural drainage to another section of 16tr St were it is piped to Kai Tai L.,a$oon' Only the sections for the west side of Parcel 0010330070 to the corner of Hancock and25"'Streets have not been offrcially designated or mapped on critical area maps as a critical drainage corridor although these sections are part ofthe overall critical drainage corridor. 3. In fact the ditch across the your propefty is part of a continuous critical drainage corridor with the identified head of the drainage starting at the corner of Thomas and Hastings Streets and ending at the Kai Tai Lagoon (See attached Map). I recommend that you obtain a copy of this complete map for Port Townsend Department of Public Works. The standard and guidelines for Critical drainage corridors are covered under Section 19.05.090 Critical area 3 -Frequently flooded areas and critical drainages corridors. Subsections include purpose, Classification, Regulated Development, and Performance Standards for Development, Buffers and Setbacks and Mitigation or compensation. If the ditch is classified as a critical drainage corridor Carol and you will have to meet or provide *re following to cross the critical drainage arei with your sewer line'from 25ft Street to your development' I think that this is the simplest process to get the sewer line from your development to 25"' street' L Your agent will have to provide a survey of the centerline of the drainage ditch with the application for a critical drainage corridor development permit. You or your agent will also have to indicate the watercourse corridor and centerline on the site plan and these areas have to be marked in the field prior to the pre-construction meeting 2. Your sewer line across the critical drainage corridor is not considered a critical facility, so you do not have to overcome that standard (critical facility, 19.05.090 Definitions). 3. Explicit approval from the DSD director will have to be received, before power equipment may enter or be used within the critical drainage coridor. This would probably be part of your development permit. This permitting will be much simpler than processing permits for a wetland 5 4. or stream crossing. One thing it will keep the permitting at the local level rather than having to possibly involve the feds and the state for wetland permitting and the state for hydraulic permit for crossingaType5water. Native and existing vegetation shall be maintained to the extent possible. If you trench through the ditch you will be disturbing the vegetation at the area of the crossing. If you tunnel under the ditch then will probably only be disturbing areas of pasture grasses within the critical drainage corridor buffer. Present vegetation in the area of the proposed crossing shown on engineering drawing consists of shrubs about 8 feet wide on both sides of the ditch. The shrubs include ocean spray (Holodiscus discolor), Nootka rose (Rosa Nutkana), common snowberry (Symphoricarpos albus) and hardhack (Spirea douglasii). Pasture beyond the shrubs on both sides ofthe ditch contain grasses consisting of 60% orchardgrass (Dactylis glomerata), 20% Reed canarygrass (Phalaris arundinacea), l07o Agrostis species, and l0%o Alopecurus sp' 5. The buffer will be defined on a site-specific basis with setbacks intended to protect life and property both on-site and off-site. The buffer will probably not be less than 25 feet but not more -on both sides of the ditch. A 25 footbuffer was established.on the ditch area on Molotsky property for the critical drainage corridor in 1998. The establishment of the buffer of 25 feet on iittr.t riO. of the ditch on Molotsky's property sets precedence in a way for the width of critical drainage conidor in this general area. 6. Your agent will probably be required to prepare a special report documenting that the proposed sewer line through or under the critical drainage corridor will not create a hazard to the property involved or to other properties located in drainage corridor' In the long run I think that it would be beneficial to both the city and the both of you to have the ditch classifiedis critical drainage corridor. It allows the city to meet its critical area goals to safeguard the public from threats to life or property associated with flooding, and preserves the natural function of flood areas and critical areas to store and control flood waters. It allow you to have the minimum buffer width allowable with relation to buffer width for the other two types of critical areas discussed in the previous paragraphs. 6 REFERENCES City of Port Townsend Municipal Code, A codification of the General Ordinances of the City of Townsend, Washington, Chapter 19.05, 1994. Port Townsend, Washington, Monthly Total Precipitation (inches) (456678), File last updated on Jul 25, 2006. Port Townsend, WashingtonNCDC L96l-1990 Monthly Normals Port Townsend, Washington, Period of Record General Climate Summary - Precipitation, Station: (456678) Port Townsend, From Year : 1948 to 2006. The Coot Company, Wetland Inventory For The D Molotsky Properly, Tax Parcel ID No. 0010330033, November 1998. 7